10302017

1

Filarial worm

Trichina worm

Lecture 6

Medical Parasitology Course (MLAB 362)

Dr Mohamed A El-Sakhawy

1

Tissue and Blood Residing

Nematodes

Common Characteristics

Biohelminth

Need intermediate host

Location (residing site)

Tissue and blood

Ovoviviparous (larviparous)

adult female deposit larvae

2

10302017

2

Filariasis Filariasis is caused by nematodes (roundworms) that inhabit

the lymphatics and subcutaneous tissues

8 main species infect humans 3 of these are responsible for

most of the morbidity due to filariasis

Wuchereria bancrofti and Brugia malayi cause lymphatic

filariasis

and Onchocerca volvulus causes onchocerciasis (river

blindness)

The other five species are Loa loa Mansonella perstans M

streptocerca M ozzardi and Brugia timori (The last species also causes

lymphatic filariasis) 3

Geographic Distribution of filaria

Among the agents of lymphatic filariasis Wuchereria

bancrofti is encountered in tropical areas worldwide

Brugia malayi is limited to Asia

The agent of river blindness Onchocerca volvulus occurs

mainly in Africa with additional foci in Latin America

and the Middle East

Loa loa and Mansonella streptocerca are found in Africa

Mansonella perstans occurs in both Africa and South

America

and Mansonella ozzardi occurs only in the American

continent 4

10302017

3

Filaria

2 types of filaria

I- Lymphatic filaria

Wuchereria bancrofti

Brugia malayi

II- Tissue filaria

Subcutaneous tissue

Onchocerca volvulus river blindness

Loa loa subcutaneous swelling

Peritoneal cavity (Mansonella perstans)

All species are transmitted by insect vectors

8 species could infect human being

5

Life Cycles of Filaria Infective larvae are transmitted by infected biting arthropods during a

blood meal

1- The larvae migrate to the appropriate site of the hosts body where they

develop into microfilariae-producing adults

2- The adults dwell in various human tissues where they can live for several

years

The agents of lymphatic filariasis reside in lymphatic vessels and lymph

nodes

Onchocerca volvulus in nodules in subcutaneous tissues

Loa loa in subcutaneous tissues

Brugia malayi and Wuchereria bancrofti in lymphatics

Mansonella streptocerca in the dermis and subcutaneous tissue

Mansonella ozzardi apparently in the subcutaneous tissues and M perstans in body

cavities and the surrounding tissues 6

10302017

4

3- The female worms produce microfilariae which circulate in

the blood except for those of Onchocerca volvulus and

Mansonella streptocerca which are found in the skin and O

volvulus which invade the eye

4- The microfilariae infect biting arthropods

mosquitoes for the agents of lymphatic filariasis

blackflies [Simulium] for Onchocerca volvulus

midges for Mansonella perstans and M streptocerca

and both midges and blackflies for Mansonella ozzardi

and deerflies [Chrysops] for Loa loa)

5- Inside the arthropod the microfilariae develop in 1 to 2

weeks into infective filariform (third-stage) larvae

7

Lymphatic filaria

Wuchereria bancrofti

Brugia malayi

8

10302017

5

Life Cycle of Brugia malayi

9

Life Cycle of Brugia malayi

The typical vector for Brugia malayi filariasis are mosquito species

During a blood meal an infected mosquito introduces third-stage

filarial larvae onto the skin of the human host where they

penetrate into the bite wound

They develop into adults that commonly reside in the lymphatics

The adult worms resemble those of Wuchereria bancrofti but are

smaller

Female worms measure 43 to 55 mm in length by 130 to 170 μm

in width and males measure 13 to 23 mm in length by 70 to 80

μm in width

Adults produce microfilariae measuring 177 to 230 μm in length

and 5 to 7 μm in width which are sheathed and have nocturnal

periodicity 10

10302017

6

The microfilariae migrate into lymph and enter the blood

stream reaching the peripheral blood

A mosquito ingests the microfilariae during a blood meal

After ingestion the microfilariae lose their sheaths and work

their way through the wall of the proventriculus and cardiac

portion of the midgut to reach the thoracic muscles

There the microfilariae develop into first-stage larvae and

subsequently into third-stage larvae

The third-stage larvae migrate through the hemocoel to the

mosquitos proboscis and can infect another human when

the mosquito takes a blood meal

11

Wuchereria bancrofti and Brugia malayi

10302017

7

Morphology I bull Adult White and thread-like Two rings

of small papillae on the head

Female5~10cm in length

Male 25~4cm and a curved tail with two

copulatory spicules

Morphology II

bull Microfilaria 177~296 microm in length a sheath with free endings Bluntly rounded anteriorly and tapers to a point posteriorly A nerve ring with no nuclei at anterior 15 of the body

Wuchereria bancrofti Brugia malayi

10302017

8

15

-Phenomen which the number of microfilariae in

peripherial blood is very low density during

daytime but increase from evening to

midnight and reach the greatest density at

10pm to 2 am

-May be related to cerebral activity and

vasoactivity of pulmonary vessels

10302017

9

Characteristic of life cycle

bull Host Mosqutoes (intermediate host)

Human (final host)

bull Location Lymphatics and lymph nodes

bull Infective stage Infective larvae

bull Transmission stage Microfilariae

bull Diagnostic stage Microfilariae

Lymphatic filariasis often consists of

asymptomatic microfilaremia

Some patients develop lymphatic dysfunction

causing lymphedema and elephantiasis(in limb or

scrotum)

Pulmonary tropical eosinophilia syndrome with

nocturnal cough and wheezing fever and

eosinophilia

10302017

10

Location (adult) lymphatic system Wb superficial and deeper

eg lower limbs groin scrotum etc

Bm superficial eg mainly in lower limbs

Infective stage filariform larva

Infection route mosquito inoculation

Discharge stage microfilaria

19

Intermediate host amp vector mosquito

Wb Culex (Anopheles)

Bm Anopheles (Aedes)

Mf show nocturnal periodicity

Nocturnal periodicity

Mfs appear in the peripheral blood in high density during the

night but hide in the pulmonary capillaries during the daytime

while the host is awaken

Wb 10 Pm ~ 2 Am

Bm 8 Pm ~ 4 Am

20

10302017

11

Lymphatic filariasis elephantiasis is the last

consequence of the swelling of limbs and scrotum

21

Early hydrocoel in a Tanzanian man with W bancrofti infection 22

10302017

12

Lymphatic filariasis elephantiasis of scrotum

Genital manifestations are frequent in W bancrofti

infections while they are rare during Bmalayi infections

23

elephantiasis Hydrocele testis

24

10302017

13

Laboratory Diagnosis of lymphatic filaria

Etiological examination

Stained thick blood smear first choice of

methods

Blood drop microscopy used in the field

Lymph node biopsy

25

Loa loa (Loaiasis or Loiasis)

(The African Eye Worm)

Distribution West and Central parts of tropical Africa

Adult Morphology as described before in the

introduction of filaria but with tuberculated

cuticle at both ends

10302017

14

Life cycle Habitat

1 Subcutaneous tissues of man free

migrating in chest back scalp axilla

groin and may be seen under the

conjunctiva

(hence the common name eye worm)

Life cycle of Loa loa

10302017

15

2 Intermediate host (vector) Female Chrysops fly (Deer fly) day biting insect (transmission as in W Bancrofi )

3 Reservoir host Monkeys 4 The infective stage is the filariform

larvae in the mouth of chrysops

5 The Microfilaria has the following characters

250 x 5

The sheath is tight

body curves are kinky

The tail is S-shaped and full of nuclei

The periodicity is diurnal with

maximum at noon

10302017

16

Microfilaria of Loa loa

Pathogenesis amp Symptomatology

Disease Loiasis Loaiasis

Wandering of adult worms may be observed in loose

connective tissues such as eye lids conjunctiva breast

amp scrotum creeping sensation irritation and

itching congestion and oedema of eye lids

It can be seen moving under the conjunctiva or

crossing the bridge of the nose but it doesnrsquot cause

blindness

10302017

17

Loiasis of the eye

2 Calabar swellings allergic reaction to worm

metabolites It is named after a town in Eastern

Nigeria

It is a transient swelling appears suddenly and

disappears gradually within 2-3 days without

suppuration

The commonest sites are forearm hands wrist

elbows and ankle It is due to hypersensitivity

(allergic reaction) to the adult worms

microfilariae and their toxic metabolites

10302017

18

3 Complications are due to invasion of the worms to

ectopic foci causing encephalopathy due to

involvement of CNS where microfilariae can be

detected in cerebrospinal fluid (CSF)

4 Arthritis Acute arthritis with joint effusion may occur

5 Also hydrocele glomerulonephritis endomyocardial

fibrosis and retinopathy can occur

Diagnosis

1 Clinical By observing the adult worm crossing

the bridge of the nose or under the conjunctiva

together with history of calabar swelling

2 Laboratory Blood examination a drop of the

peripheral blood is taken during the day time

(10 am to 2 pm) and is examined fresh for

motile microfilariae and stained thick smear

for fixed microfilariae

10302017

19

3 History of calabar swelling

4 Serological and intradermal test

5 Eosinophiliaamp leucocytosis

Control

Treatment of infected persons

Protection by screening or by fly repellents when

visiting forests in endemic area

Chrysops control is difficult because it breeds in

swampy areas of forest

10302017

20

Laboratory Diagnosis of filaria

Identification of microfilariae by microscopic examination is the most

practical diagnostic procedure

Examination of blood samples will allow identification of microfilariae

of Wuchereria bancrofti Brugia malayi Loa loa Mansonella perstans and M

ozzardi

It is important to time the blood collection with the known

periodicity of the microfilariae

The blood sample can be a thick smear stained with Giemsa or

hematoxylin and eosin For increased sensitivity concentration

techniques can be used

These include centrifugation of the blood sample lyzed in 2 formalin

(Knotts technique) or filtration through a Nucleopore membrane

39

Examination of skin snips will identify microfilariae

of Onchocerca volvulus and Mansonella streptocerca Skin

snips can be obtained using a corneal-scleral punch or

more simply a scalpel and needle The sample must be

allowed to incubate for 30 minutes to 2 hours in saline or

culture medium

Antigen detection using an immunoassay for

circulating filarial antigens constitutes a useful

diagnostic approach because microfilaremia can be

low and variable A rapid-format

immunochromatographic test

40

10302017

21

Molecular diagnosis using PCR is available for W bancrofti

and B malayi

1048707 Identification of adult worms is possible from tissue samples collected during nodulectomies (onchocerciasis) or

during subcutaneous biopsies or worm removal from the eye

(loiasis)

1048707 Antibody detection is of limited value Substantial antigenic cross reactivity exists between filaria and other

helminths and a positive serologic test does not distinguish

between past and current infection

41

42

a Infection with

Wuchereria bancrofti

elephantiasis

b infection with Loa

loa eyelid swelling

c onchocercosis

cutaneous nodules

caused by Onchocerca

volvulus

d blindness caused by

O volvulus

e Trichinella spiralis

larvae in rat

musculature

f larva migrans

externa

10302017

22

Trichina worm Trichinella spiralis

43

و ونحى انخزير )قال تعانى بسى هللا انرح انرحيى يتة وانذ و عهيكى ان ا حر إ

حيى غفور ر هللا اضطر غير باغ ول عاد فإ به ف (ويا أهم نغير هللا

115اآليــة -انحم

Biological characteristics

Zoonosis

Ovoviviparous

Adult amp larva live in the same host individual

Adult small intestine

Larva striated muscle

44

10302017

23

Trichinella spiralis larvae in

muscle section 45 A higher power magnification

Larva of Trichinella spiralis

46

10302017

24

47

Life Cycle of T spiralis

Trichinellosis is acquired by ingesting meat containing cysts

(encysted larvae) of Trichinella

After exposure to gastric acid and pepsin the larvae are

released from the cysts and invade the small bowel mucosa

where they develop into adult worms

(female 22 mm in length males 12 mm life span in the

small bowel 4 weeks)

After 1 week the females release larvae that migrate to the

striated muscles where they encyst

Encystment is completed in 4 to 5 weeks and the encysted

larvae may remain viable for several years 48

10302017

25

Ingestion of the encysted larvae perpetuates the

cycle

Rats and rodents are primarily responsible for

maintaining the endemicity of this infection

Carnivorousomnivorous animals such as pigs or

bears feed on infected rodents or meat from other

animals

Humans are accidentally infected when eating

improperly processed meat of these carnivorous

animals (or eating food contaminated with such

meat)

49

Main Points of Life Cycle

Infective stage capsulated larva

Infection route eating raw or improperly cooked pork

or its products

No extra-hostal developing but must change host to

finish the life cycle exists many reservoir host

Human acts as IH and DH

50

10302017

26

Pathogenesis

Main pathogenic factor larva

Invasion stage (intestinal phase) minor digestive

disturbance

Migration stage (muscular phase) diarrhea myalgias

abdominal pain vomiting weakness blood eosinophilia

circumorbital edema myositis Muscular tenderness

Encystment stage recovery

51

Epidemiologiy

Cosmopolitan esp in Europe and North-America

China due to raw pork consumption

52

Diagnosis

Based on the basis of clinical symptoms and history and

eosinophilia

Etiological diagnosis

Biopsy of skeletal muscle

Immunological diagnosis (antibody detection)

10302017

27

Control methods

Hygienic education

Properly cooking pork

Low temperature storage of pork

(all larvae are killed at -15ordmC for 24hs)

Scientific raising pigs heat treatment of garbage used as pig

food

53

10302017

2

Filariasis Filariasis is caused by nematodes (roundworms) that inhabit

the lymphatics and subcutaneous tissues

8 main species infect humans 3 of these are responsible for

most of the morbidity due to filariasis

Wuchereria bancrofti and Brugia malayi cause lymphatic

filariasis

and Onchocerca volvulus causes onchocerciasis (river

blindness)

The other five species are Loa loa Mansonella perstans M

streptocerca M ozzardi and Brugia timori (The last species also causes

lymphatic filariasis) 3

Geographic Distribution of filaria

Among the agents of lymphatic filariasis Wuchereria

bancrofti is encountered in tropical areas worldwide

Brugia malayi is limited to Asia

The agent of river blindness Onchocerca volvulus occurs

mainly in Africa with additional foci in Latin America

and the Middle East

Loa loa and Mansonella streptocerca are found in Africa

Mansonella perstans occurs in both Africa and South

America

and Mansonella ozzardi occurs only in the American

continent 4

10302017

3

Filaria

2 types of filaria

I- Lymphatic filaria

Wuchereria bancrofti

Brugia malayi

II- Tissue filaria

Subcutaneous tissue

Onchocerca volvulus river blindness

Loa loa subcutaneous swelling

Peritoneal cavity (Mansonella perstans)

All species are transmitted by insect vectors

8 species could infect human being

5

Life Cycles of Filaria Infective larvae are transmitted by infected biting arthropods during a

blood meal

1- The larvae migrate to the appropriate site of the hosts body where they

develop into microfilariae-producing adults

2- The adults dwell in various human tissues where they can live for several

years

The agents of lymphatic filariasis reside in lymphatic vessels and lymph

nodes

Onchocerca volvulus in nodules in subcutaneous tissues

Loa loa in subcutaneous tissues

Brugia malayi and Wuchereria bancrofti in lymphatics

Mansonella streptocerca in the dermis and subcutaneous tissue

Mansonella ozzardi apparently in the subcutaneous tissues and M perstans in body

cavities and the surrounding tissues 6

10302017

4

3- The female worms produce microfilariae which circulate in

the blood except for those of Onchocerca volvulus and

Mansonella streptocerca which are found in the skin and O

volvulus which invade the eye

4- The microfilariae infect biting arthropods

mosquitoes for the agents of lymphatic filariasis

blackflies [Simulium] for Onchocerca volvulus

midges for Mansonella perstans and M streptocerca

and both midges and blackflies for Mansonella ozzardi

and deerflies [Chrysops] for Loa loa)

5- Inside the arthropod the microfilariae develop in 1 to 2

weeks into infective filariform (third-stage) larvae

7

Lymphatic filaria

Wuchereria bancrofti

Brugia malayi

8

10302017

5

Life Cycle of Brugia malayi

9

Life Cycle of Brugia malayi

The typical vector for Brugia malayi filariasis are mosquito species

During a blood meal an infected mosquito introduces third-stage

filarial larvae onto the skin of the human host where they

penetrate into the bite wound

They develop into adults that commonly reside in the lymphatics

The adult worms resemble those of Wuchereria bancrofti but are

smaller

Female worms measure 43 to 55 mm in length by 130 to 170 μm

in width and males measure 13 to 23 mm in length by 70 to 80

μm in width

Adults produce microfilariae measuring 177 to 230 μm in length

and 5 to 7 μm in width which are sheathed and have nocturnal

periodicity 10

10302017

6

The microfilariae migrate into lymph and enter the blood

stream reaching the peripheral blood

A mosquito ingests the microfilariae during a blood meal

After ingestion the microfilariae lose their sheaths and work

their way through the wall of the proventriculus and cardiac

portion of the midgut to reach the thoracic muscles

There the microfilariae develop into first-stage larvae and

subsequently into third-stage larvae

The third-stage larvae migrate through the hemocoel to the

mosquitos proboscis and can infect another human when

the mosquito takes a blood meal

11

Wuchereria bancrofti and Brugia malayi

10302017

7

Morphology I bull Adult White and thread-like Two rings

of small papillae on the head

Female5~10cm in length

Male 25~4cm and a curved tail with two

copulatory spicules

Morphology II

bull Microfilaria 177~296 microm in length a sheath with free endings Bluntly rounded anteriorly and tapers to a point posteriorly A nerve ring with no nuclei at anterior 15 of the body

Wuchereria bancrofti Brugia malayi

10302017

8

15

-Phenomen which the number of microfilariae in

peripherial blood is very low density during

daytime but increase from evening to

midnight and reach the greatest density at

10pm to 2 am

-May be related to cerebral activity and

vasoactivity of pulmonary vessels

10302017

9

Characteristic of life cycle

bull Host Mosqutoes (intermediate host)

Human (final host)

bull Location Lymphatics and lymph nodes

bull Infective stage Infective larvae

bull Transmission stage Microfilariae

bull Diagnostic stage Microfilariae

Lymphatic filariasis often consists of

asymptomatic microfilaremia

Some patients develop lymphatic dysfunction

causing lymphedema and elephantiasis(in limb or

scrotum)

Pulmonary tropical eosinophilia syndrome with

nocturnal cough and wheezing fever and

eosinophilia

10302017

10

Location (adult) lymphatic system Wb superficial and deeper

eg lower limbs groin scrotum etc

Bm superficial eg mainly in lower limbs

Infective stage filariform larva

Infection route mosquito inoculation

Discharge stage microfilaria

19

Intermediate host amp vector mosquito

Wb Culex (Anopheles)

Bm Anopheles (Aedes)

Mf show nocturnal periodicity

Nocturnal periodicity

Mfs appear in the peripheral blood in high density during the

night but hide in the pulmonary capillaries during the daytime

while the host is awaken

Wb 10 Pm ~ 2 Am

Bm 8 Pm ~ 4 Am

20

10302017

11

Lymphatic filariasis elephantiasis is the last

consequence of the swelling of limbs and scrotum

21

Early hydrocoel in a Tanzanian man with W bancrofti infection 22

10302017

12

Lymphatic filariasis elephantiasis of scrotum

Genital manifestations are frequent in W bancrofti

infections while they are rare during Bmalayi infections

23

elephantiasis Hydrocele testis

24

10302017

13

Laboratory Diagnosis of lymphatic filaria

Etiological examination

Stained thick blood smear first choice of

methods

Blood drop microscopy used in the field

Lymph node biopsy

25

Loa loa (Loaiasis or Loiasis)

(The African Eye Worm)

Distribution West and Central parts of tropical Africa

Adult Morphology as described before in the

introduction of filaria but with tuberculated

cuticle at both ends

10302017

14

Life cycle Habitat

1 Subcutaneous tissues of man free

migrating in chest back scalp axilla

groin and may be seen under the

conjunctiva

(hence the common name eye worm)

Life cycle of Loa loa

10302017

15

2 Intermediate host (vector) Female Chrysops fly (Deer fly) day biting insect (transmission as in W Bancrofi )

3 Reservoir host Monkeys 4 The infective stage is the filariform

larvae in the mouth of chrysops

5 The Microfilaria has the following characters

250 x 5

The sheath is tight

body curves are kinky

The tail is S-shaped and full of nuclei

The periodicity is diurnal with

maximum at noon

10302017

16

Microfilaria of Loa loa

Pathogenesis amp Symptomatology

Disease Loiasis Loaiasis

Wandering of adult worms may be observed in loose

connective tissues such as eye lids conjunctiva breast

amp scrotum creeping sensation irritation and

itching congestion and oedema of eye lids

It can be seen moving under the conjunctiva or

crossing the bridge of the nose but it doesnrsquot cause

blindness

10302017

17

Loiasis of the eye

2 Calabar swellings allergic reaction to worm

metabolites It is named after a town in Eastern

Nigeria

It is a transient swelling appears suddenly and

disappears gradually within 2-3 days without

suppuration

The commonest sites are forearm hands wrist

elbows and ankle It is due to hypersensitivity

(allergic reaction) to the adult worms

microfilariae and their toxic metabolites

10302017

18

3 Complications are due to invasion of the worms to

ectopic foci causing encephalopathy due to

involvement of CNS where microfilariae can be

detected in cerebrospinal fluid (CSF)

4 Arthritis Acute arthritis with joint effusion may occur

5 Also hydrocele glomerulonephritis endomyocardial

fibrosis and retinopathy can occur

Diagnosis

1 Clinical By observing the adult worm crossing

the bridge of the nose or under the conjunctiva

together with history of calabar swelling

2 Laboratory Blood examination a drop of the

peripheral blood is taken during the day time

(10 am to 2 pm) and is examined fresh for

motile microfilariae and stained thick smear

for fixed microfilariae

10302017

19

3 History of calabar swelling

4 Serological and intradermal test

5 Eosinophiliaamp leucocytosis

Control

Treatment of infected persons

Protection by screening or by fly repellents when

visiting forests in endemic area

Chrysops control is difficult because it breeds in

swampy areas of forest

10302017

20

Laboratory Diagnosis of filaria

Identification of microfilariae by microscopic examination is the most

practical diagnostic procedure

Examination of blood samples will allow identification of microfilariae

of Wuchereria bancrofti Brugia malayi Loa loa Mansonella perstans and M

ozzardi

It is important to time the blood collection with the known

periodicity of the microfilariae

The blood sample can be a thick smear stained with Giemsa or

hematoxylin and eosin For increased sensitivity concentration

techniques can be used

These include centrifugation of the blood sample lyzed in 2 formalin

(Knotts technique) or filtration through a Nucleopore membrane

39

Examination of skin snips will identify microfilariae

of Onchocerca volvulus and Mansonella streptocerca Skin

snips can be obtained using a corneal-scleral punch or

more simply a scalpel and needle The sample must be

allowed to incubate for 30 minutes to 2 hours in saline or

culture medium

Antigen detection using an immunoassay for

circulating filarial antigens constitutes a useful

diagnostic approach because microfilaremia can be

low and variable A rapid-format

immunochromatographic test

40

10302017

21

Molecular diagnosis using PCR is available for W bancrofti

and B malayi

1048707 Identification of adult worms is possible from tissue samples collected during nodulectomies (onchocerciasis) or

during subcutaneous biopsies or worm removal from the eye

(loiasis)

1048707 Antibody detection is of limited value Substantial antigenic cross reactivity exists between filaria and other

helminths and a positive serologic test does not distinguish

between past and current infection

41

42

a Infection with

Wuchereria bancrofti

elephantiasis

b infection with Loa

loa eyelid swelling

c onchocercosis

cutaneous nodules

caused by Onchocerca

volvulus

d blindness caused by

O volvulus

e Trichinella spiralis

larvae in rat

musculature

f larva migrans

externa

10302017

22

Trichina worm Trichinella spiralis

43

و ونحى انخزير )قال تعانى بسى هللا انرح انرحيى يتة وانذ و عهيكى ان ا حر إ

حيى غفور ر هللا اضطر غير باغ ول عاد فإ به ف (ويا أهم نغير هللا

115اآليــة -انحم

Biological characteristics

Zoonosis

Ovoviviparous

Adult amp larva live in the same host individual

Adult small intestine

Larva striated muscle

44

10302017

23

Trichinella spiralis larvae in

muscle section 45 A higher power magnification

Larva of Trichinella spiralis

46

10302017

24

47

Life Cycle of T spiralis

Trichinellosis is acquired by ingesting meat containing cysts

(encysted larvae) of Trichinella

After exposure to gastric acid and pepsin the larvae are

released from the cysts and invade the small bowel mucosa

where they develop into adult worms

(female 22 mm in length males 12 mm life span in the

small bowel 4 weeks)

After 1 week the females release larvae that migrate to the

striated muscles where they encyst

Encystment is completed in 4 to 5 weeks and the encysted

larvae may remain viable for several years 48

10302017

25

Ingestion of the encysted larvae perpetuates the

cycle

Rats and rodents are primarily responsible for

maintaining the endemicity of this infection

Carnivorousomnivorous animals such as pigs or

bears feed on infected rodents or meat from other

animals

Humans are accidentally infected when eating

improperly processed meat of these carnivorous

animals (or eating food contaminated with such

meat)

49

Main Points of Life Cycle

Infective stage capsulated larva

Infection route eating raw or improperly cooked pork

or its products

No extra-hostal developing but must change host to

finish the life cycle exists many reservoir host

Human acts as IH and DH

50

10302017

26

Pathogenesis

Main pathogenic factor larva

Invasion stage (intestinal phase) minor digestive

disturbance

Migration stage (muscular phase) diarrhea myalgias

abdominal pain vomiting weakness blood eosinophilia

circumorbital edema myositis Muscular tenderness

Encystment stage recovery

51

Epidemiologiy

Cosmopolitan esp in Europe and North-America

China due to raw pork consumption

52

Diagnosis

Based on the basis of clinical symptoms and history and

eosinophilia

Etiological diagnosis

Biopsy of skeletal muscle

Immunological diagnosis (antibody detection)

10302017

27

Control methods

Hygienic education

Properly cooking pork

Low temperature storage of pork

(all larvae are killed at -15ordmC for 24hs)

Scientific raising pigs heat treatment of garbage used as pig

food

53

10302017

3

Filaria

2 types of filaria

I- Lymphatic filaria

Wuchereria bancrofti

Brugia malayi

II- Tissue filaria

Subcutaneous tissue

Onchocerca volvulus river blindness

Loa loa subcutaneous swelling

Peritoneal cavity (Mansonella perstans)

All species are transmitted by insect vectors

8 species could infect human being

5

Life Cycles of Filaria Infective larvae are transmitted by infected biting arthropods during a

blood meal

1- The larvae migrate to the appropriate site of the hosts body where they

develop into microfilariae-producing adults

2- The adults dwell in various human tissues where they can live for several

years

The agents of lymphatic filariasis reside in lymphatic vessels and lymph

nodes

Onchocerca volvulus in nodules in subcutaneous tissues

Loa loa in subcutaneous tissues

Brugia malayi and Wuchereria bancrofti in lymphatics

Mansonella streptocerca in the dermis and subcutaneous tissue

Mansonella ozzardi apparently in the subcutaneous tissues and M perstans in body

cavities and the surrounding tissues 6

10302017

4

3- The female worms produce microfilariae which circulate in

the blood except for those of Onchocerca volvulus and

Mansonella streptocerca which are found in the skin and O

volvulus which invade the eye

4- The microfilariae infect biting arthropods

mosquitoes for the agents of lymphatic filariasis

blackflies [Simulium] for Onchocerca volvulus

midges for Mansonella perstans and M streptocerca

and both midges and blackflies for Mansonella ozzardi

and deerflies [Chrysops] for Loa loa)

5- Inside the arthropod the microfilariae develop in 1 to 2

weeks into infective filariform (third-stage) larvae

7

Lymphatic filaria

Wuchereria bancrofti

Brugia malayi

8

10302017

5

Life Cycle of Brugia malayi

9

Life Cycle of Brugia malayi

The typical vector for Brugia malayi filariasis are mosquito species

During a blood meal an infected mosquito introduces third-stage

filarial larvae onto the skin of the human host where they

penetrate into the bite wound

They develop into adults that commonly reside in the lymphatics

The adult worms resemble those of Wuchereria bancrofti but are

smaller

Female worms measure 43 to 55 mm in length by 130 to 170 μm

in width and males measure 13 to 23 mm in length by 70 to 80

μm in width

Adults produce microfilariae measuring 177 to 230 μm in length

and 5 to 7 μm in width which are sheathed and have nocturnal

periodicity 10

10302017

6

The microfilariae migrate into lymph and enter the blood

stream reaching the peripheral blood

A mosquito ingests the microfilariae during a blood meal

After ingestion the microfilariae lose their sheaths and work

their way through the wall of the proventriculus and cardiac

portion of the midgut to reach the thoracic muscles

There the microfilariae develop into first-stage larvae and

subsequently into third-stage larvae

The third-stage larvae migrate through the hemocoel to the

mosquitos proboscis and can infect another human when

the mosquito takes a blood meal

11

Wuchereria bancrofti and Brugia malayi

10302017

7

Morphology I bull Adult White and thread-like Two rings

of small papillae on the head

Female5~10cm in length

Male 25~4cm and a curved tail with two

copulatory spicules

Morphology II

bull Microfilaria 177~296 microm in length a sheath with free endings Bluntly rounded anteriorly and tapers to a point posteriorly A nerve ring with no nuclei at anterior 15 of the body

Wuchereria bancrofti Brugia malayi

10302017

8

15

-Phenomen which the number of microfilariae in

peripherial blood is very low density during

daytime but increase from evening to

midnight and reach the greatest density at

10pm to 2 am

-May be related to cerebral activity and

vasoactivity of pulmonary vessels

10302017

9

Characteristic of life cycle

bull Host Mosqutoes (intermediate host)

Human (final host)

bull Location Lymphatics and lymph nodes

bull Infective stage Infective larvae

bull Transmission stage Microfilariae

bull Diagnostic stage Microfilariae

Lymphatic filariasis often consists of

asymptomatic microfilaremia

Some patients develop lymphatic dysfunction

causing lymphedema and elephantiasis(in limb or

scrotum)

Pulmonary tropical eosinophilia syndrome with

nocturnal cough and wheezing fever and

eosinophilia

10302017

10

Location (adult) lymphatic system Wb superficial and deeper

eg lower limbs groin scrotum etc

Bm superficial eg mainly in lower limbs

Infective stage filariform larva

Infection route mosquito inoculation

Discharge stage microfilaria

19

Intermediate host amp vector mosquito

Wb Culex (Anopheles)

Bm Anopheles (Aedes)

Mf show nocturnal periodicity

Nocturnal periodicity

Mfs appear in the peripheral blood in high density during the

night but hide in the pulmonary capillaries during the daytime

while the host is awaken

Wb 10 Pm ~ 2 Am

Bm 8 Pm ~ 4 Am

20

10302017

11

Lymphatic filariasis elephantiasis is the last

consequence of the swelling of limbs and scrotum

21

Early hydrocoel in a Tanzanian man with W bancrofti infection 22

10302017

12

Lymphatic filariasis elephantiasis of scrotum

Genital manifestations are frequent in W bancrofti

infections while they are rare during Bmalayi infections

23

elephantiasis Hydrocele testis

24

10302017

13

Laboratory Diagnosis of lymphatic filaria

Etiological examination

Stained thick blood smear first choice of

methods

Blood drop microscopy used in the field

Lymph node biopsy

25

Loa loa (Loaiasis or Loiasis)

(The African Eye Worm)

Distribution West and Central parts of tropical Africa

Adult Morphology as described before in the

introduction of filaria but with tuberculated

cuticle at both ends

10302017

14

Life cycle Habitat

1 Subcutaneous tissues of man free

migrating in chest back scalp axilla

groin and may be seen under the

conjunctiva

(hence the common name eye worm)

Life cycle of Loa loa

10302017

15

2 Intermediate host (vector) Female Chrysops fly (Deer fly) day biting insect (transmission as in W Bancrofi )

3 Reservoir host Monkeys 4 The infective stage is the filariform

larvae in the mouth of chrysops

5 The Microfilaria has the following characters

250 x 5

The sheath is tight

body curves are kinky

The tail is S-shaped and full of nuclei

The periodicity is diurnal with

maximum at noon

10302017

16

Microfilaria of Loa loa

Pathogenesis amp Symptomatology

Disease Loiasis Loaiasis

Wandering of adult worms may be observed in loose

connective tissues such as eye lids conjunctiva breast

amp scrotum creeping sensation irritation and

itching congestion and oedema of eye lids

It can be seen moving under the conjunctiva or

crossing the bridge of the nose but it doesnrsquot cause

blindness

10302017

17

Loiasis of the eye

2 Calabar swellings allergic reaction to worm

metabolites It is named after a town in Eastern

Nigeria

It is a transient swelling appears suddenly and

disappears gradually within 2-3 days without

suppuration

The commonest sites are forearm hands wrist

elbows and ankle It is due to hypersensitivity

(allergic reaction) to the adult worms

microfilariae and their toxic metabolites

10302017

18

3 Complications are due to invasion of the worms to

ectopic foci causing encephalopathy due to

involvement of CNS where microfilariae can be

detected in cerebrospinal fluid (CSF)

4 Arthritis Acute arthritis with joint effusion may occur

5 Also hydrocele glomerulonephritis endomyocardial

fibrosis and retinopathy can occur

Diagnosis

1 Clinical By observing the adult worm crossing

the bridge of the nose or under the conjunctiva

together with history of calabar swelling

2 Laboratory Blood examination a drop of the

peripheral blood is taken during the day time

(10 am to 2 pm) and is examined fresh for

motile microfilariae and stained thick smear

for fixed microfilariae

10302017

19

3 History of calabar swelling

4 Serological and intradermal test

5 Eosinophiliaamp leucocytosis

Control

Treatment of infected persons

Protection by screening or by fly repellents when

visiting forests in endemic area

Chrysops control is difficult because it breeds in

swampy areas of forest

10302017

20

Laboratory Diagnosis of filaria

Identification of microfilariae by microscopic examination is the most

practical diagnostic procedure

Examination of blood samples will allow identification of microfilariae

of Wuchereria bancrofti Brugia malayi Loa loa Mansonella perstans and M

ozzardi

It is important to time the blood collection with the known

periodicity of the microfilariae

The blood sample can be a thick smear stained with Giemsa or

hematoxylin and eosin For increased sensitivity concentration

techniques can be used

These include centrifugation of the blood sample lyzed in 2 formalin

(Knotts technique) or filtration through a Nucleopore membrane

39

Examination of skin snips will identify microfilariae

of Onchocerca volvulus and Mansonella streptocerca Skin

snips can be obtained using a corneal-scleral punch or

more simply a scalpel and needle The sample must be

allowed to incubate for 30 minutes to 2 hours in saline or

culture medium

Antigen detection using an immunoassay for

circulating filarial antigens constitutes a useful

diagnostic approach because microfilaremia can be

low and variable A rapid-format

immunochromatographic test

40

10302017

21

Molecular diagnosis using PCR is available for W bancrofti

and B malayi

1048707 Identification of adult worms is possible from tissue samples collected during nodulectomies (onchocerciasis) or

during subcutaneous biopsies or worm removal from the eye

(loiasis)

1048707 Antibody detection is of limited value Substantial antigenic cross reactivity exists between filaria and other

helminths and a positive serologic test does not distinguish

between past and current infection

41

42

a Infection with

Wuchereria bancrofti

elephantiasis

b infection with Loa

loa eyelid swelling

c onchocercosis

cutaneous nodules

caused by Onchocerca

volvulus

d blindness caused by

O volvulus

e Trichinella spiralis

larvae in rat

musculature

f larva migrans

externa

10302017

22

Trichina worm Trichinella spiralis

43

و ونحى انخزير )قال تعانى بسى هللا انرح انرحيى يتة وانذ و عهيكى ان ا حر إ

حيى غفور ر هللا اضطر غير باغ ول عاد فإ به ف (ويا أهم نغير هللا

115اآليــة -انحم

Biological characteristics

Zoonosis

Ovoviviparous

Adult amp larva live in the same host individual

Adult small intestine

Larva striated muscle

44

10302017

23

Trichinella spiralis larvae in

muscle section 45 A higher power magnification

Larva of Trichinella spiralis

46

10302017

24

47

Life Cycle of T spiralis

Trichinellosis is acquired by ingesting meat containing cysts

(encysted larvae) of Trichinella

After exposure to gastric acid and pepsin the larvae are

released from the cysts and invade the small bowel mucosa

where they develop into adult worms

(female 22 mm in length males 12 mm life span in the

small bowel 4 weeks)

After 1 week the females release larvae that migrate to the

striated muscles where they encyst

Encystment is completed in 4 to 5 weeks and the encysted

larvae may remain viable for several years 48

10302017

25

Ingestion of the encysted larvae perpetuates the

cycle

Rats and rodents are primarily responsible for

maintaining the endemicity of this infection

Carnivorousomnivorous animals such as pigs or

bears feed on infected rodents or meat from other

animals

Humans are accidentally infected when eating

improperly processed meat of these carnivorous

animals (or eating food contaminated with such

meat)

49

Main Points of Life Cycle

Infective stage capsulated larva

Infection route eating raw or improperly cooked pork

or its products

No extra-hostal developing but must change host to

finish the life cycle exists many reservoir host

Human acts as IH and DH

50

10302017

26

Pathogenesis

Main pathogenic factor larva

Invasion stage (intestinal phase) minor digestive

disturbance

Migration stage (muscular phase) diarrhea myalgias

abdominal pain vomiting weakness blood eosinophilia

circumorbital edema myositis Muscular tenderness

Encystment stage recovery

51

Epidemiologiy

Cosmopolitan esp in Europe and North-America

China due to raw pork consumption

52

Diagnosis

Based on the basis of clinical symptoms and history and

eosinophilia

Etiological diagnosis

Biopsy of skeletal muscle

Immunological diagnosis (antibody detection)

10302017

27

Control methods

Hygienic education

Properly cooking pork

Low temperature storage of pork

(all larvae are killed at -15ordmC for 24hs)

Scientific raising pigs heat treatment of garbage used as pig

food

53

10302017

4

3- The female worms produce microfilariae which circulate in

the blood except for those of Onchocerca volvulus and

Mansonella streptocerca which are found in the skin and O

volvulus which invade the eye

4- The microfilariae infect biting arthropods

mosquitoes for the agents of lymphatic filariasis

blackflies [Simulium] for Onchocerca volvulus

midges for Mansonella perstans and M streptocerca

and both midges and blackflies for Mansonella ozzardi

and deerflies [Chrysops] for Loa loa)

5- Inside the arthropod the microfilariae develop in 1 to 2

weeks into infective filariform (third-stage) larvae

7

Lymphatic filaria

Wuchereria bancrofti

Brugia malayi

8

10302017

5

Life Cycle of Brugia malayi

9

Life Cycle of Brugia malayi

The typical vector for Brugia malayi filariasis are mosquito species

During a blood meal an infected mosquito introduces third-stage

filarial larvae onto the skin of the human host where they

penetrate into the bite wound

They develop into adults that commonly reside in the lymphatics

The adult worms resemble those of Wuchereria bancrofti but are

smaller

Female worms measure 43 to 55 mm in length by 130 to 170 μm

in width and males measure 13 to 23 mm in length by 70 to 80

μm in width

Adults produce microfilariae measuring 177 to 230 μm in length

and 5 to 7 μm in width which are sheathed and have nocturnal

periodicity 10

10302017

6

The microfilariae migrate into lymph and enter the blood

stream reaching the peripheral blood

A mosquito ingests the microfilariae during a blood meal

After ingestion the microfilariae lose their sheaths and work

their way through the wall of the proventriculus and cardiac

portion of the midgut to reach the thoracic muscles

There the microfilariae develop into first-stage larvae and

subsequently into third-stage larvae

The third-stage larvae migrate through the hemocoel to the

mosquitos proboscis and can infect another human when

the mosquito takes a blood meal

11

Wuchereria bancrofti and Brugia malayi

10302017

7

Morphology I bull Adult White and thread-like Two rings

of small papillae on the head

Female5~10cm in length

Male 25~4cm and a curved tail with two

copulatory spicules

Morphology II

bull Microfilaria 177~296 microm in length a sheath with free endings Bluntly rounded anteriorly and tapers to a point posteriorly A nerve ring with no nuclei at anterior 15 of the body

Wuchereria bancrofti Brugia malayi

10302017

8

15

-Phenomen which the number of microfilariae in

peripherial blood is very low density during

daytime but increase from evening to

midnight and reach the greatest density at

10pm to 2 am

-May be related to cerebral activity and

vasoactivity of pulmonary vessels

10302017

9

Characteristic of life cycle

bull Host Mosqutoes (intermediate host)

Human (final host)

bull Location Lymphatics and lymph nodes

bull Infective stage Infective larvae

bull Transmission stage Microfilariae

bull Diagnostic stage Microfilariae

Lymphatic filariasis often consists of

asymptomatic microfilaremia

Some patients develop lymphatic dysfunction

causing lymphedema and elephantiasis(in limb or

scrotum)

Pulmonary tropical eosinophilia syndrome with

nocturnal cough and wheezing fever and

eosinophilia

10302017

10

Location (adult) lymphatic system Wb superficial and deeper

eg lower limbs groin scrotum etc

Bm superficial eg mainly in lower limbs

Infective stage filariform larva

Infection route mosquito inoculation

Discharge stage microfilaria

19

Intermediate host amp vector mosquito

Wb Culex (Anopheles)

Bm Anopheles (Aedes)

Mf show nocturnal periodicity

Nocturnal periodicity

Mfs appear in the peripheral blood in high density during the

night but hide in the pulmonary capillaries during the daytime

while the host is awaken

Wb 10 Pm ~ 2 Am

Bm 8 Pm ~ 4 Am

20

10302017

11

Lymphatic filariasis elephantiasis is the last

consequence of the swelling of limbs and scrotum

21

Early hydrocoel in a Tanzanian man with W bancrofti infection 22

10302017

12

Lymphatic filariasis elephantiasis of scrotum

Genital manifestations are frequent in W bancrofti

infections while they are rare during Bmalayi infections

23

elephantiasis Hydrocele testis

24

10302017

13

Laboratory Diagnosis of lymphatic filaria

Etiological examination

Stained thick blood smear first choice of

methods

Blood drop microscopy used in the field

Lymph node biopsy

25

Loa loa (Loaiasis or Loiasis)

(The African Eye Worm)

Distribution West and Central parts of tropical Africa

Adult Morphology as described before in the

introduction of filaria but with tuberculated

cuticle at both ends

10302017

14

Life cycle Habitat

1 Subcutaneous tissues of man free

migrating in chest back scalp axilla

groin and may be seen under the

conjunctiva

(hence the common name eye worm)

Life cycle of Loa loa

10302017

15

2 Intermediate host (vector) Female Chrysops fly (Deer fly) day biting insect (transmission as in W Bancrofi )

3 Reservoir host Monkeys 4 The infective stage is the filariform

larvae in the mouth of chrysops

5 The Microfilaria has the following characters

250 x 5

The sheath is tight

body curves are kinky

The tail is S-shaped and full of nuclei

The periodicity is diurnal with

maximum at noon

10302017

16

Microfilaria of Loa loa

Pathogenesis amp Symptomatology

Disease Loiasis Loaiasis

Wandering of adult worms may be observed in loose

connective tissues such as eye lids conjunctiva breast

amp scrotum creeping sensation irritation and

itching congestion and oedema of eye lids

It can be seen moving under the conjunctiva or

crossing the bridge of the nose but it doesnrsquot cause

blindness

10302017

17

Loiasis of the eye

2 Calabar swellings allergic reaction to worm

metabolites It is named after a town in Eastern

Nigeria

It is a transient swelling appears suddenly and

disappears gradually within 2-3 days without

suppuration

The commonest sites are forearm hands wrist

elbows and ankle It is due to hypersensitivity

(allergic reaction) to the adult worms

microfilariae and their toxic metabolites

10302017

18

3 Complications are due to invasion of the worms to

ectopic foci causing encephalopathy due to

involvement of CNS where microfilariae can be

detected in cerebrospinal fluid (CSF)

4 Arthritis Acute arthritis with joint effusion may occur

5 Also hydrocele glomerulonephritis endomyocardial

fibrosis and retinopathy can occur

Diagnosis

1 Clinical By observing the adult worm crossing

the bridge of the nose or under the conjunctiva

together with history of calabar swelling

2 Laboratory Blood examination a drop of the

peripheral blood is taken during the day time

(10 am to 2 pm) and is examined fresh for

motile microfilariae and stained thick smear

for fixed microfilariae

10302017

19

3 History of calabar swelling

4 Serological and intradermal test

5 Eosinophiliaamp leucocytosis

Control

Treatment of infected persons

Protection by screening or by fly repellents when

visiting forests in endemic area

Chrysops control is difficult because it breeds in

swampy areas of forest

10302017

20

Laboratory Diagnosis of filaria

Identification of microfilariae by microscopic examination is the most

practical diagnostic procedure

Examination of blood samples will allow identification of microfilariae

of Wuchereria bancrofti Brugia malayi Loa loa Mansonella perstans and M

ozzardi

It is important to time the blood collection with the known

periodicity of the microfilariae

The blood sample can be a thick smear stained with Giemsa or

hematoxylin and eosin For increased sensitivity concentration

techniques can be used

These include centrifugation of the blood sample lyzed in 2 formalin

(Knotts technique) or filtration through a Nucleopore membrane

39

Examination of skin snips will identify microfilariae

of Onchocerca volvulus and Mansonella streptocerca Skin

snips can be obtained using a corneal-scleral punch or

more simply a scalpel and needle The sample must be

allowed to incubate for 30 minutes to 2 hours in saline or

culture medium

Antigen detection using an immunoassay for

circulating filarial antigens constitutes a useful

diagnostic approach because microfilaremia can be

low and variable A rapid-format

immunochromatographic test

40

10302017

21

Molecular diagnosis using PCR is available for W bancrofti

and B malayi

1048707 Identification of adult worms is possible from tissue samples collected during nodulectomies (onchocerciasis) or

during subcutaneous biopsies or worm removal from the eye

(loiasis)

1048707 Antibody detection is of limited value Substantial antigenic cross reactivity exists between filaria and other

helminths and a positive serologic test does not distinguish

between past and current infection

41

42

a Infection with

Wuchereria bancrofti

elephantiasis

b infection with Loa

loa eyelid swelling

c onchocercosis

cutaneous nodules

caused by Onchocerca

volvulus

d blindness caused by

O volvulus

e Trichinella spiralis

larvae in rat

musculature

f larva migrans

externa

10302017

22

Trichina worm Trichinella spiralis

43

و ونحى انخزير )قال تعانى بسى هللا انرح انرحيى يتة وانذ و عهيكى ان ا حر إ

حيى غفور ر هللا اضطر غير باغ ول عاد فإ به ف (ويا أهم نغير هللا

115اآليــة -انحم

Biological characteristics

Zoonosis

Ovoviviparous

Adult amp larva live in the same host individual

Adult small intestine

Larva striated muscle

44

10302017

23

Trichinella spiralis larvae in

muscle section 45 A higher power magnification

Larva of Trichinella spiralis

46

10302017

24

47

Life Cycle of T spiralis

Trichinellosis is acquired by ingesting meat containing cysts

(encysted larvae) of Trichinella

After exposure to gastric acid and pepsin the larvae are

released from the cysts and invade the small bowel mucosa

where they develop into adult worms

(female 22 mm in length males 12 mm life span in the

small bowel 4 weeks)

After 1 week the females release larvae that migrate to the

striated muscles where they encyst

Encystment is completed in 4 to 5 weeks and the encysted

larvae may remain viable for several years 48

10302017

25

Ingestion of the encysted larvae perpetuates the

cycle

Rats and rodents are primarily responsible for

maintaining the endemicity of this infection

Carnivorousomnivorous animals such as pigs or

bears feed on infected rodents or meat from other

animals

Humans are accidentally infected when eating

improperly processed meat of these carnivorous

animals (or eating food contaminated with such

meat)

49

Main Points of Life Cycle

Infective stage capsulated larva

Infection route eating raw or improperly cooked pork

or its products

No extra-hostal developing but must change host to

finish the life cycle exists many reservoir host

Human acts as IH and DH

50

10302017

26

Pathogenesis

Main pathogenic factor larva

Invasion stage (intestinal phase) minor digestive

disturbance

Migration stage (muscular phase) diarrhea myalgias

abdominal pain vomiting weakness blood eosinophilia

circumorbital edema myositis Muscular tenderness

Encystment stage recovery

51

Epidemiologiy

Cosmopolitan esp in Europe and North-America

China due to raw pork consumption

52

Diagnosis

Based on the basis of clinical symptoms and history and

eosinophilia

Etiological diagnosis

Biopsy of skeletal muscle

Immunological diagnosis (antibody detection)

10302017

27

Control methods

Hygienic education

Properly cooking pork

Low temperature storage of pork

(all larvae are killed at -15ordmC for 24hs)

Scientific raising pigs heat treatment of garbage used as pig

food

53

10302017

5

Life Cycle of Brugia malayi

9

Life Cycle of Brugia malayi

The typical vector for Brugia malayi filariasis are mosquito species

During a blood meal an infected mosquito introduces third-stage

filarial larvae onto the skin of the human host where they

penetrate into the bite wound

They develop into adults that commonly reside in the lymphatics

The adult worms resemble those of Wuchereria bancrofti but are

smaller

Female worms measure 43 to 55 mm in length by 130 to 170 μm

in width and males measure 13 to 23 mm in length by 70 to 80

μm in width

Adults produce microfilariae measuring 177 to 230 μm in length

and 5 to 7 μm in width which are sheathed and have nocturnal

periodicity 10

10302017

6

The microfilariae migrate into lymph and enter the blood

stream reaching the peripheral blood

A mosquito ingests the microfilariae during a blood meal

After ingestion the microfilariae lose their sheaths and work

their way through the wall of the proventriculus and cardiac

portion of the midgut to reach the thoracic muscles

There the microfilariae develop into first-stage larvae and

subsequently into third-stage larvae

The third-stage larvae migrate through the hemocoel to the

mosquitos proboscis and can infect another human when

the mosquito takes a blood meal

11

Wuchereria bancrofti and Brugia malayi

10302017

7

Morphology I bull Adult White and thread-like Two rings

of small papillae on the head

Female5~10cm in length

Male 25~4cm and a curved tail with two

copulatory spicules

Morphology II

bull Microfilaria 177~296 microm in length a sheath with free endings Bluntly rounded anteriorly and tapers to a point posteriorly A nerve ring with no nuclei at anterior 15 of the body

Wuchereria bancrofti Brugia malayi

10302017

8

15

-Phenomen which the number of microfilariae in

peripherial blood is very low density during

daytime but increase from evening to

midnight and reach the greatest density at

10pm to 2 am

-May be related to cerebral activity and

vasoactivity of pulmonary vessels

10302017

9

Characteristic of life cycle

bull Host Mosqutoes (intermediate host)

Human (final host)

bull Location Lymphatics and lymph nodes

bull Infective stage Infective larvae

bull Transmission stage Microfilariae

bull Diagnostic stage Microfilariae

Lymphatic filariasis often consists of

asymptomatic microfilaremia

Some patients develop lymphatic dysfunction

causing lymphedema and elephantiasis(in limb or

scrotum)

Pulmonary tropical eosinophilia syndrome with

nocturnal cough and wheezing fever and

eosinophilia

10302017

10

Location (adult) lymphatic system Wb superficial and deeper

eg lower limbs groin scrotum etc

Bm superficial eg mainly in lower limbs

Infective stage filariform larva

Infection route mosquito inoculation

Discharge stage microfilaria

19

Intermediate host amp vector mosquito

Wb Culex (Anopheles)

Bm Anopheles (Aedes)

Mf show nocturnal periodicity

Nocturnal periodicity

Mfs appear in the peripheral blood in high density during the

night but hide in the pulmonary capillaries during the daytime

while the host is awaken

Wb 10 Pm ~ 2 Am

Bm 8 Pm ~ 4 Am

20

10302017

11

Lymphatic filariasis elephantiasis is the last

consequence of the swelling of limbs and scrotum

21

Early hydrocoel in a Tanzanian man with W bancrofti infection 22

10302017

12

Lymphatic filariasis elephantiasis of scrotum

Genital manifestations are frequent in W bancrofti

infections while they are rare during Bmalayi infections

23

elephantiasis Hydrocele testis

24

10302017

13

Laboratory Diagnosis of lymphatic filaria

Etiological examination

Stained thick blood smear first choice of

methods

Blood drop microscopy used in the field

Lymph node biopsy

25

Loa loa (Loaiasis or Loiasis)

(The African Eye Worm)

Distribution West and Central parts of tropical Africa

Adult Morphology as described before in the

introduction of filaria but with tuberculated

cuticle at both ends

10302017

14

Life cycle Habitat

1 Subcutaneous tissues of man free

migrating in chest back scalp axilla

groin and may be seen under the

conjunctiva

(hence the common name eye worm)

Life cycle of Loa loa

10302017

15

2 Intermediate host (vector) Female Chrysops fly (Deer fly) day biting insect (transmission as in W Bancrofi )

3 Reservoir host Monkeys 4 The infective stage is the filariform

larvae in the mouth of chrysops

5 The Microfilaria has the following characters

250 x 5

The sheath is tight

body curves are kinky

The tail is S-shaped and full of nuclei

The periodicity is diurnal with

maximum at noon

10302017

16

Microfilaria of Loa loa

Pathogenesis amp Symptomatology

Disease Loiasis Loaiasis

Wandering of adult worms may be observed in loose

connective tissues such as eye lids conjunctiva breast

amp scrotum creeping sensation irritation and

itching congestion and oedema of eye lids

It can be seen moving under the conjunctiva or

crossing the bridge of the nose but it doesnrsquot cause

blindness

10302017

17

Loiasis of the eye

2 Calabar swellings allergic reaction to worm

metabolites It is named after a town in Eastern

Nigeria

It is a transient swelling appears suddenly and

disappears gradually within 2-3 days without

suppuration

The commonest sites are forearm hands wrist

elbows and ankle It is due to hypersensitivity

(allergic reaction) to the adult worms

microfilariae and their toxic metabolites

10302017

18

3 Complications are due to invasion of the worms to

ectopic foci causing encephalopathy due to

involvement of CNS where microfilariae can be

detected in cerebrospinal fluid (CSF)

4 Arthritis Acute arthritis with joint effusion may occur

5 Also hydrocele glomerulonephritis endomyocardial

fibrosis and retinopathy can occur

Diagnosis

1 Clinical By observing the adult worm crossing

the bridge of the nose or under the conjunctiva

together with history of calabar swelling

2 Laboratory Blood examination a drop of the

peripheral blood is taken during the day time

(10 am to 2 pm) and is examined fresh for

motile microfilariae and stained thick smear

for fixed microfilariae

10302017

19

3 History of calabar swelling

4 Serological and intradermal test

5 Eosinophiliaamp leucocytosis

Control

Treatment of infected persons

Protection by screening or by fly repellents when

visiting forests in endemic area

Chrysops control is difficult because it breeds in

swampy areas of forest

10302017

20

Laboratory Diagnosis of filaria

Identification of microfilariae by microscopic examination is the most

practical diagnostic procedure

Examination of blood samples will allow identification of microfilariae

of Wuchereria bancrofti Brugia malayi Loa loa Mansonella perstans and M

ozzardi

It is important to time the blood collection with the known

periodicity of the microfilariae

The blood sample can be a thick smear stained with Giemsa or

hematoxylin and eosin For increased sensitivity concentration

techniques can be used

These include centrifugation of the blood sample lyzed in 2 formalin

(Knotts technique) or filtration through a Nucleopore membrane

39

Examination of skin snips will identify microfilariae

of Onchocerca volvulus and Mansonella streptocerca Skin

snips can be obtained using a corneal-scleral punch or

more simply a scalpel and needle The sample must be

allowed to incubate for 30 minutes to 2 hours in saline or

culture medium

Antigen detection using an immunoassay for

circulating filarial antigens constitutes a useful

diagnostic approach because microfilaremia can be

low and variable A rapid-format

immunochromatographic test

40

10302017

21

Molecular diagnosis using PCR is available for W bancrofti

and B malayi

1048707 Identification of adult worms is possible from tissue samples collected during nodulectomies (onchocerciasis) or

during subcutaneous biopsies or worm removal from the eye

(loiasis)

1048707 Antibody detection is of limited value Substantial antigenic cross reactivity exists between filaria and other

helminths and a positive serologic test does not distinguish

between past and current infection

41

42

a Infection with

Wuchereria bancrofti

elephantiasis

b infection with Loa

loa eyelid swelling

c onchocercosis

cutaneous nodules

caused by Onchocerca

volvulus

d blindness caused by

O volvulus

e Trichinella spiralis

larvae in rat

musculature

f larva migrans

externa

10302017

22

Trichina worm Trichinella spiralis

43

و ونحى انخزير )قال تعانى بسى هللا انرح انرحيى يتة وانذ و عهيكى ان ا حر إ

حيى غفور ر هللا اضطر غير باغ ول عاد فإ به ف (ويا أهم نغير هللا

115اآليــة -انحم

Biological characteristics

Zoonosis

Ovoviviparous

Adult amp larva live in the same host individual

Adult small intestine

Larva striated muscle

44

10302017

23

Trichinella spiralis larvae in

muscle section 45 A higher power magnification

Larva of Trichinella spiralis

46

10302017

24

47

Life Cycle of T spiralis

Trichinellosis is acquired by ingesting meat containing cysts

(encysted larvae) of Trichinella

After exposure to gastric acid and pepsin the larvae are

released from the cysts and invade the small bowel mucosa

where they develop into adult worms

(female 22 mm in length males 12 mm life span in the

small bowel 4 weeks)

After 1 week the females release larvae that migrate to the

striated muscles where they encyst

Encystment is completed in 4 to 5 weeks and the encysted

larvae may remain viable for several years 48

10302017

25

Ingestion of the encysted larvae perpetuates the

cycle

Rats and rodents are primarily responsible for

maintaining the endemicity of this infection

Carnivorousomnivorous animals such as pigs or

bears feed on infected rodents or meat from other

animals

Humans are accidentally infected when eating

improperly processed meat of these carnivorous

animals (or eating food contaminated with such

meat)

49

Main Points of Life Cycle

Infective stage capsulated larva

Infection route eating raw or improperly cooked pork

or its products

No extra-hostal developing but must change host to

finish the life cycle exists many reservoir host

Human acts as IH and DH

50

10302017

26

Pathogenesis

Main pathogenic factor larva

Invasion stage (intestinal phase) minor digestive

disturbance

Migration stage (muscular phase) diarrhea myalgias

abdominal pain vomiting weakness blood eosinophilia

circumorbital edema myositis Muscular tenderness

Encystment stage recovery

51

Epidemiologiy

Cosmopolitan esp in Europe and North-America

China due to raw pork consumption

52

Diagnosis

Based on the basis of clinical symptoms and history and

eosinophilia

Etiological diagnosis

Biopsy of skeletal muscle

Immunological diagnosis (antibody detection)

10302017

27

Control methods

Hygienic education

Properly cooking pork

Low temperature storage of pork

(all larvae are killed at -15ordmC for 24hs)

Scientific raising pigs heat treatment of garbage used as pig

food

53

10302017

6

The microfilariae migrate into lymph and enter the blood

stream reaching the peripheral blood

A mosquito ingests the microfilariae during a blood meal

After ingestion the microfilariae lose their sheaths and work

their way through the wall of the proventriculus and cardiac

portion of the midgut to reach the thoracic muscles

There the microfilariae develop into first-stage larvae and

subsequently into third-stage larvae

The third-stage larvae migrate through the hemocoel to the

mosquitos proboscis and can infect another human when

the mosquito takes a blood meal

11

Wuchereria bancrofti and Brugia malayi

10302017

7

Morphology I bull Adult White and thread-like Two rings

of small papillae on the head

Female5~10cm in length

Male 25~4cm and a curved tail with two

copulatory spicules

Morphology II

bull Microfilaria 177~296 microm in length a sheath with free endings Bluntly rounded anteriorly and tapers to a point posteriorly A nerve ring with no nuclei at anterior 15 of the body

Wuchereria bancrofti Brugia malayi

10302017

8

15

-Phenomen which the number of microfilariae in

peripherial blood is very low density during

daytime but increase from evening to

midnight and reach the greatest density at

10pm to 2 am

-May be related to cerebral activity and

vasoactivity of pulmonary vessels

10302017

9

Characteristic of life cycle

bull Host Mosqutoes (intermediate host)

Human (final host)

bull Location Lymphatics and lymph nodes

bull Infective stage Infective larvae

bull Transmission stage Microfilariae

bull Diagnostic stage Microfilariae

Lymphatic filariasis often consists of

asymptomatic microfilaremia

Some patients develop lymphatic dysfunction

causing lymphedema and elephantiasis(in limb or

scrotum)

Pulmonary tropical eosinophilia syndrome with

nocturnal cough and wheezing fever and

eosinophilia

10302017

10

Location (adult) lymphatic system Wb superficial and deeper

eg lower limbs groin scrotum etc

Bm superficial eg mainly in lower limbs

Infective stage filariform larva

Infection route mosquito inoculation

Discharge stage microfilaria

19

Intermediate host amp vector mosquito

Wb Culex (Anopheles)

Bm Anopheles (Aedes)

Mf show nocturnal periodicity

Nocturnal periodicity

Mfs appear in the peripheral blood in high density during the

night but hide in the pulmonary capillaries during the daytime

while the host is awaken

Wb 10 Pm ~ 2 Am

Bm 8 Pm ~ 4 Am

20

10302017

11

Lymphatic filariasis elephantiasis is the last

consequence of the swelling of limbs and scrotum

21

Early hydrocoel in a Tanzanian man with W bancrofti infection 22

10302017

12

Lymphatic filariasis elephantiasis of scrotum

Genital manifestations are frequent in W bancrofti

infections while they are rare during Bmalayi infections

23

elephantiasis Hydrocele testis

24

10302017

13

Laboratory Diagnosis of lymphatic filaria

Etiological examination

Stained thick blood smear first choice of

methods

Blood drop microscopy used in the field

Lymph node biopsy

25

Loa loa (Loaiasis or Loiasis)

(The African Eye Worm)

Distribution West and Central parts of tropical Africa

Adult Morphology as described before in the

introduction of filaria but with tuberculated

cuticle at both ends

10302017

14

Life cycle Habitat

1 Subcutaneous tissues of man free

migrating in chest back scalp axilla

groin and may be seen under the

conjunctiva

(hence the common name eye worm)

Life cycle of Loa loa

10302017

15

2 Intermediate host (vector) Female Chrysops fly (Deer fly) day biting insect (transmission as in W Bancrofi )

3 Reservoir host Monkeys 4 The infective stage is the filariform

larvae in the mouth of chrysops

5 The Microfilaria has the following characters

250 x 5

The sheath is tight

body curves are kinky

The tail is S-shaped and full of nuclei

The periodicity is diurnal with

maximum at noon

10302017

16

Microfilaria of Loa loa

Pathogenesis amp Symptomatology

Disease Loiasis Loaiasis

Wandering of adult worms may be observed in loose

connective tissues such as eye lids conjunctiva breast

amp scrotum creeping sensation irritation and

itching congestion and oedema of eye lids

It can be seen moving under the conjunctiva or

crossing the bridge of the nose but it doesnrsquot cause

blindness

10302017

17

Loiasis of the eye

2 Calabar swellings allergic reaction to worm

metabolites It is named after a town in Eastern

Nigeria

It is a transient swelling appears suddenly and

disappears gradually within 2-3 days without

suppuration

The commonest sites are forearm hands wrist

elbows and ankle It is due to hypersensitivity

(allergic reaction) to the adult worms

microfilariae and their toxic metabolites

10302017

18

3 Complications are due to invasion of the worms to

ectopic foci causing encephalopathy due to

involvement of CNS where microfilariae can be

detected in cerebrospinal fluid (CSF)

4 Arthritis Acute arthritis with joint effusion may occur

5 Also hydrocele glomerulonephritis endomyocardial

fibrosis and retinopathy can occur

Diagnosis

1 Clinical By observing the adult worm crossing

the bridge of the nose or under the conjunctiva

together with history of calabar swelling

2 Laboratory Blood examination a drop of the

peripheral blood is taken during the day time

(10 am to 2 pm) and is examined fresh for

motile microfilariae and stained thick smear

for fixed microfilariae

10302017

19

3 History of calabar swelling

4 Serological and intradermal test

5 Eosinophiliaamp leucocytosis

Control

Treatment of infected persons

Protection by screening or by fly repellents when

visiting forests in endemic area

Chrysops control is difficult because it breeds in

swampy areas of forest

10302017

20

Laboratory Diagnosis of filaria

Identification of microfilariae by microscopic examination is the most

practical diagnostic procedure

Examination of blood samples will allow identification of microfilariae

of Wuchereria bancrofti Brugia malayi Loa loa Mansonella perstans and M

ozzardi

It is important to time the blood collection with the known

periodicity of the microfilariae

The blood sample can be a thick smear stained with Giemsa or

hematoxylin and eosin For increased sensitivity concentration

techniques can be used

These include centrifugation of the blood sample lyzed in 2 formalin

(Knotts technique) or filtration through a Nucleopore membrane

39

Examination of skin snips will identify microfilariae

of Onchocerca volvulus and Mansonella streptocerca Skin

snips can be obtained using a corneal-scleral punch or

more simply a scalpel and needle The sample must be

allowed to incubate for 30 minutes to 2 hours in saline or

culture medium

Antigen detection using an immunoassay for

circulating filarial antigens constitutes a useful

diagnostic approach because microfilaremia can be

low and variable A rapid-format

immunochromatographic test

40

10302017

21

Molecular diagnosis using PCR is available for W bancrofti

and B malayi

1048707 Identification of adult worms is possible from tissue samples collected during nodulectomies (onchocerciasis) or

during subcutaneous biopsies or worm removal from the eye

(loiasis)

1048707 Antibody detection is of limited value Substantial antigenic cross reactivity exists between filaria and other

helminths and a positive serologic test does not distinguish

between past and current infection

41

42

a Infection with

Wuchereria bancrofti

elephantiasis

b infection with Loa

loa eyelid swelling

c onchocercosis

cutaneous nodules

caused by Onchocerca

volvulus

d blindness caused by

O volvulus

e Trichinella spiralis

larvae in rat

musculature

f larva migrans

externa

10302017

22

Trichina worm Trichinella spiralis

43

و ونحى انخزير )قال تعانى بسى هللا انرح انرحيى يتة وانذ و عهيكى ان ا حر إ

حيى غفور ر هللا اضطر غير باغ ول عاد فإ به ف (ويا أهم نغير هللا

115اآليــة -انحم

Biological characteristics

Zoonosis

Ovoviviparous

Adult amp larva live in the same host individual

Adult small intestine

Larva striated muscle

44

10302017

23

Trichinella spiralis larvae in

muscle section 45 A higher power magnification

Larva of Trichinella spiralis

46

10302017

24

47

Life Cycle of T spiralis

Trichinellosis is acquired by ingesting meat containing cysts

(encysted larvae) of Trichinella

After exposure to gastric acid and pepsin the larvae are

released from the cysts and invade the small bowel mucosa

where they develop into adult worms

(female 22 mm in length males 12 mm life span in the

small bowel 4 weeks)

After 1 week the females release larvae that migrate to the

striated muscles where they encyst

Encystment is completed in 4 to 5 weeks and the encysted

larvae may remain viable for several years 48

10302017

25

Ingestion of the encysted larvae perpetuates the

cycle

Rats and rodents are primarily responsible for

maintaining the endemicity of this infection

Carnivorousomnivorous animals such as pigs or

bears feed on infected rodents or meat from other

animals

Humans are accidentally infected when eating

improperly processed meat of these carnivorous

animals (or eating food contaminated with such

meat)

49

Main Points of Life Cycle

Infective stage capsulated larva

Infection route eating raw or improperly cooked pork

or its products

No extra-hostal developing but must change host to

finish the life cycle exists many reservoir host

Human acts as IH and DH

50

10302017

26

Pathogenesis

Main pathogenic factor larva

Invasion stage (intestinal phase) minor digestive

disturbance

Migration stage (muscular phase) diarrhea myalgias

abdominal pain vomiting weakness blood eosinophilia

circumorbital edema myositis Muscular tenderness

Encystment stage recovery

51

Epidemiologiy

Cosmopolitan esp in Europe and North-America

China due to raw pork consumption

52

Diagnosis

Based on the basis of clinical symptoms and history and

eosinophilia

Etiological diagnosis

Biopsy of skeletal muscle

Immunological diagnosis (antibody detection)

10302017

27

Control methods

Hygienic education

Properly cooking pork

Low temperature storage of pork

(all larvae are killed at -15ordmC for 24hs)

Scientific raising pigs heat treatment of garbage used as pig

food

53

10302017

7

Morphology I bull Adult White and thread-like Two rings

of small papillae on the head

Female5~10cm in length

Male 25~4cm and a curved tail with two

copulatory spicules

Morphology II

bull Microfilaria 177~296 microm in length a sheath with free endings Bluntly rounded anteriorly and tapers to a point posteriorly A nerve ring with no nuclei at anterior 15 of the body

Wuchereria bancrofti Brugia malayi

10302017

8

15

-Phenomen which the number of microfilariae in

peripherial blood is very low density during

daytime but increase from evening to

midnight and reach the greatest density at

10pm to 2 am

-May be related to cerebral activity and

vasoactivity of pulmonary vessels

10302017

9

Characteristic of life cycle

bull Host Mosqutoes (intermediate host)

Human (final host)

bull Location Lymphatics and lymph nodes

bull Infective stage Infective larvae

bull Transmission stage Microfilariae

bull Diagnostic stage Microfilariae

Lymphatic filariasis often consists of

asymptomatic microfilaremia

Some patients develop lymphatic dysfunction

causing lymphedema and elephantiasis(in limb or

scrotum)

Pulmonary tropical eosinophilia syndrome with

nocturnal cough and wheezing fever and

eosinophilia

10302017

10

Location (adult) lymphatic system Wb superficial and deeper

eg lower limbs groin scrotum etc

Bm superficial eg mainly in lower limbs

Infective stage filariform larva

Infection route mosquito inoculation

Discharge stage microfilaria

19

Intermediate host amp vector mosquito

Wb Culex (Anopheles)

Bm Anopheles (Aedes)

Mf show nocturnal periodicity

Nocturnal periodicity

Mfs appear in the peripheral blood in high density during the

night but hide in the pulmonary capillaries during the daytime

while the host is awaken

Wb 10 Pm ~ 2 Am

Bm 8 Pm ~ 4 Am

20

10302017

11

Lymphatic filariasis elephantiasis is the last

consequence of the swelling of limbs and scrotum

21

Early hydrocoel in a Tanzanian man with W bancrofti infection 22

10302017

12

Lymphatic filariasis elephantiasis of scrotum

Genital manifestations are frequent in W bancrofti

infections while they are rare during Bmalayi infections

23

elephantiasis Hydrocele testis

24

10302017

13

Laboratory Diagnosis of lymphatic filaria

Etiological examination

Stained thick blood smear first choice of

methods

Blood drop microscopy used in the field

Lymph node biopsy

25

Loa loa (Loaiasis or Loiasis)

(The African Eye Worm)

Distribution West and Central parts of tropical Africa

Adult Morphology as described before in the

introduction of filaria but with tuberculated

cuticle at both ends

10302017

14

Life cycle Habitat

1 Subcutaneous tissues of man free

migrating in chest back scalp axilla

groin and may be seen under the

conjunctiva

(hence the common name eye worm)

Life cycle of Loa loa

10302017

15

2 Intermediate host (vector) Female Chrysops fly (Deer fly) day biting insect (transmission as in W Bancrofi )

3 Reservoir host Monkeys 4 The infective stage is the filariform

larvae in the mouth of chrysops

5 The Microfilaria has the following characters

250 x 5

The sheath is tight

body curves are kinky

The tail is S-shaped and full of nuclei

The periodicity is diurnal with

maximum at noon

10302017

16

Microfilaria of Loa loa

Pathogenesis amp Symptomatology

Disease Loiasis Loaiasis

Wandering of adult worms may be observed in loose

connective tissues such as eye lids conjunctiva breast

amp scrotum creeping sensation irritation and

itching congestion and oedema of eye lids

It can be seen moving under the conjunctiva or

crossing the bridge of the nose but it doesnrsquot cause

blindness

10302017

17

Loiasis of the eye

2 Calabar swellings allergic reaction to worm

metabolites It is named after a town in Eastern

Nigeria

It is a transient swelling appears suddenly and

disappears gradually within 2-3 days without

suppuration

The commonest sites are forearm hands wrist

elbows and ankle It is due to hypersensitivity

(allergic reaction) to the adult worms

microfilariae and their toxic metabolites

10302017

18

3 Complications are due to invasion of the worms to

ectopic foci causing encephalopathy due to

involvement of CNS where microfilariae can be

detected in cerebrospinal fluid (CSF)

4 Arthritis Acute arthritis with joint effusion may occur

5 Also hydrocele glomerulonephritis endomyocardial

fibrosis and retinopathy can occur

Diagnosis

1 Clinical By observing the adult worm crossing

the bridge of the nose or under the conjunctiva

together with history of calabar swelling

2 Laboratory Blood examination a drop of the

peripheral blood is taken during the day time

(10 am to 2 pm) and is examined fresh for

motile microfilariae and stained thick smear

for fixed microfilariae

10302017

19

3 History of calabar swelling

4 Serological and intradermal test

5 Eosinophiliaamp leucocytosis

Control

Treatment of infected persons

Protection by screening or by fly repellents when

visiting forests in endemic area

Chrysops control is difficult because it breeds in

swampy areas of forest

10302017

20

Laboratory Diagnosis of filaria

Identification of microfilariae by microscopic examination is the most

practical diagnostic procedure

Examination of blood samples will allow identification of microfilariae

of Wuchereria bancrofti Brugia malayi Loa loa Mansonella perstans and M

ozzardi

It is important to time the blood collection with the known

periodicity of the microfilariae

The blood sample can be a thick smear stained with Giemsa or

hematoxylin and eosin For increased sensitivity concentration

techniques can be used

These include centrifugation of the blood sample lyzed in 2 formalin

(Knotts technique) or filtration through a Nucleopore membrane

39

Examination of skin snips will identify microfilariae

of Onchocerca volvulus and Mansonella streptocerca Skin

snips can be obtained using a corneal-scleral punch or

more simply a scalpel and needle The sample must be

allowed to incubate for 30 minutes to 2 hours in saline or

culture medium

Antigen detection using an immunoassay for

circulating filarial antigens constitutes a useful

diagnostic approach because microfilaremia can be

low and variable A rapid-format

immunochromatographic test

40

10302017

21

Molecular diagnosis using PCR is available for W bancrofti

and B malayi

1048707 Identification of adult worms is possible from tissue samples collected during nodulectomies (onchocerciasis) or

during subcutaneous biopsies or worm removal from the eye

(loiasis)

1048707 Antibody detection is of limited value Substantial antigenic cross reactivity exists between filaria and other

helminths and a positive serologic test does not distinguish

between past and current infection

41

42

a Infection with

Wuchereria bancrofti

elephantiasis

b infection with Loa

loa eyelid swelling

c onchocercosis

cutaneous nodules

caused by Onchocerca

volvulus

d blindness caused by

O volvulus

e Trichinella spiralis

larvae in rat

musculature

f larva migrans

externa

10302017

22

Trichina worm Trichinella spiralis

43

و ونحى انخزير )قال تعانى بسى هللا انرح انرحيى يتة وانذ و عهيكى ان ا حر إ

حيى غفور ر هللا اضطر غير باغ ول عاد فإ به ف (ويا أهم نغير هللا

115اآليــة -انحم

Biological characteristics

Zoonosis

Ovoviviparous

Adult amp larva live in the same host individual

Adult small intestine

Larva striated muscle

44

10302017

23

Trichinella spiralis larvae in

muscle section 45 A higher power magnification

Larva of Trichinella spiralis

46

10302017

24

47

Life Cycle of T spiralis

Trichinellosis is acquired by ingesting meat containing cysts

(encysted larvae) of Trichinella

After exposure to gastric acid and pepsin the larvae are

released from the cysts and invade the small bowel mucosa

where they develop into adult worms

(female 22 mm in length males 12 mm life span in the

small bowel 4 weeks)

After 1 week the females release larvae that migrate to the

striated muscles where they encyst

Encystment is completed in 4 to 5 weeks and the encysted

larvae may remain viable for several years 48

10302017

25

Ingestion of the encysted larvae perpetuates the

cycle

Rats and rodents are primarily responsible for

maintaining the endemicity of this infection

Carnivorousomnivorous animals such as pigs or

bears feed on infected rodents or meat from other

animals

Humans are accidentally infected when eating

improperly processed meat of these carnivorous

animals (or eating food contaminated with such

meat)

49

Main Points of Life Cycle

Infective stage capsulated larva

Infection route eating raw or improperly cooked pork

or its products

No extra-hostal developing but must change host to

finish the life cycle exists many reservoir host

Human acts as IH and DH

50

10302017

26

Pathogenesis

Main pathogenic factor larva

Invasion stage (intestinal phase) minor digestive

disturbance

Migration stage (muscular phase) diarrhea myalgias

abdominal pain vomiting weakness blood eosinophilia

circumorbital edema myositis Muscular tenderness

Encystment stage recovery

51

Epidemiologiy

Cosmopolitan esp in Europe and North-America

China due to raw pork consumption

52

Diagnosis

Based on the basis of clinical symptoms and history and

eosinophilia

Etiological diagnosis

Biopsy of skeletal muscle

Immunological diagnosis (antibody detection)

10302017

27

Control methods

Hygienic education

Properly cooking pork

Low temperature storage of pork

(all larvae are killed at -15ordmC for 24hs)

Scientific raising pigs heat treatment of garbage used as pig

food

53

10302017

8

15

-Phenomen which the number of microfilariae in

peripherial blood is very low density during

daytime but increase from evening to

midnight and reach the greatest density at

10pm to 2 am

-May be related to cerebral activity and

vasoactivity of pulmonary vessels

10302017

9

Characteristic of life cycle

bull Host Mosqutoes (intermediate host)

Human (final host)

bull Location Lymphatics and lymph nodes

bull Infective stage Infective larvae

bull Transmission stage Microfilariae

bull Diagnostic stage Microfilariae

Lymphatic filariasis often consists of

asymptomatic microfilaremia

Some patients develop lymphatic dysfunction

causing lymphedema and elephantiasis(in limb or

scrotum)

Pulmonary tropical eosinophilia syndrome with

nocturnal cough and wheezing fever and

eosinophilia

10302017

10

Location (adult) lymphatic system Wb superficial and deeper

eg lower limbs groin scrotum etc

Bm superficial eg mainly in lower limbs

Infective stage filariform larva

Infection route mosquito inoculation

Discharge stage microfilaria

19

Intermediate host amp vector mosquito

Wb Culex (Anopheles)

Bm Anopheles (Aedes)

Mf show nocturnal periodicity

Nocturnal periodicity

Mfs appear in the peripheral blood in high density during the

night but hide in the pulmonary capillaries during the daytime

while the host is awaken

Wb 10 Pm ~ 2 Am

Bm 8 Pm ~ 4 Am

20

10302017

11

Lymphatic filariasis elephantiasis is the last

consequence of the swelling of limbs and scrotum

21

Early hydrocoel in a Tanzanian man with W bancrofti infection 22

10302017

12

Lymphatic filariasis elephantiasis of scrotum

Genital manifestations are frequent in W bancrofti

infections while they are rare during Bmalayi infections

23

elephantiasis Hydrocele testis

24

10302017

13

Laboratory Diagnosis of lymphatic filaria

Etiological examination

Stained thick blood smear first choice of

methods

Blood drop microscopy used in the field

Lymph node biopsy

25

Loa loa (Loaiasis or Loiasis)

(The African Eye Worm)

Distribution West and Central parts of tropical Africa

Adult Morphology as described before in the

introduction of filaria but with tuberculated

cuticle at both ends

10302017

14

Life cycle Habitat

1 Subcutaneous tissues of man free

migrating in chest back scalp axilla

groin and may be seen under the

conjunctiva

(hence the common name eye worm)

Life cycle of Loa loa

10302017

15

2 Intermediate host (vector) Female Chrysops fly (Deer fly) day biting insect (transmission as in W Bancrofi )

3 Reservoir host Monkeys 4 The infective stage is the filariform

larvae in the mouth of chrysops

5 The Microfilaria has the following characters

250 x 5

The sheath is tight

body curves are kinky

The tail is S-shaped and full of nuclei

The periodicity is diurnal with

maximum at noon

10302017

16

Microfilaria of Loa loa

Pathogenesis amp Symptomatology

Disease Loiasis Loaiasis

Wandering of adult worms may be observed in loose

connective tissues such as eye lids conjunctiva breast

amp scrotum creeping sensation irritation and

itching congestion and oedema of eye lids

It can be seen moving under the conjunctiva or

crossing the bridge of the nose but it doesnrsquot cause

blindness

10302017

17

Loiasis of the eye

2 Calabar swellings allergic reaction to worm

metabolites It is named after a town in Eastern

Nigeria

It is a transient swelling appears suddenly and

disappears gradually within 2-3 days without

suppuration

The commonest sites are forearm hands wrist

elbows and ankle It is due to hypersensitivity

(allergic reaction) to the adult worms

microfilariae and their toxic metabolites

10302017

18

3 Complications are due to invasion of the worms to

ectopic foci causing encephalopathy due to

involvement of CNS where microfilariae can be

detected in cerebrospinal fluid (CSF)

4 Arthritis Acute arthritis with joint effusion may occur

5 Also hydrocele glomerulonephritis endomyocardial

fibrosis and retinopathy can occur

Diagnosis

1 Clinical By observing the adult worm crossing

the bridge of the nose or under the conjunctiva

together with history of calabar swelling

2 Laboratory Blood examination a drop of the

peripheral blood is taken during the day time

(10 am to 2 pm) and is examined fresh for

motile microfilariae and stained thick smear

for fixed microfilariae

10302017

19

3 History of calabar swelling

4 Serological and intradermal test

5 Eosinophiliaamp leucocytosis

Control

Treatment of infected persons

Protection by screening or by fly repellents when

visiting forests in endemic area

Chrysops control is difficult because it breeds in

swampy areas of forest

10302017

20

Laboratory Diagnosis of filaria

Identification of microfilariae by microscopic examination is the most

practical diagnostic procedure

Examination of blood samples will allow identification of microfilariae

of Wuchereria bancrofti Brugia malayi Loa loa Mansonella perstans and M

ozzardi

It is important to time the blood collection with the known

periodicity of the microfilariae

The blood sample can be a thick smear stained with Giemsa or

hematoxylin and eosin For increased sensitivity concentration

techniques can be used

These include centrifugation of the blood sample lyzed in 2 formalin

(Knotts technique) or filtration through a Nucleopore membrane

39

Examination of skin snips will identify microfilariae

of Onchocerca volvulus and Mansonella streptocerca Skin

snips can be obtained using a corneal-scleral punch or

more simply a scalpel and needle The sample must be

allowed to incubate for 30 minutes to 2 hours in saline or

culture medium

Antigen detection using an immunoassay for

circulating filarial antigens constitutes a useful

diagnostic approach because microfilaremia can be

low and variable A rapid-format

immunochromatographic test

40

10302017

21

Molecular diagnosis using PCR is available for W bancrofti

and B malayi

1048707 Identification of adult worms is possible from tissue samples collected during nodulectomies (onchocerciasis) or

during subcutaneous biopsies or worm removal from the eye

(loiasis)

1048707 Antibody detection is of limited value Substantial antigenic cross reactivity exists between filaria and other

helminths and a positive serologic test does not distinguish

between past and current infection

41

42

a Infection with

Wuchereria bancrofti

elephantiasis

b infection with Loa

loa eyelid swelling

c onchocercosis

cutaneous nodules

caused by Onchocerca

volvulus

d blindness caused by

O volvulus

e Trichinella spiralis

larvae in rat

musculature

f larva migrans

externa

10302017

22

Trichina worm Trichinella spiralis

43

و ونحى انخزير )قال تعانى بسى هللا انرح انرحيى يتة وانذ و عهيكى ان ا حر إ

حيى غفور ر هللا اضطر غير باغ ول عاد فإ به ف (ويا أهم نغير هللا

115اآليــة -انحم

Biological characteristics

Zoonosis

Ovoviviparous

Adult amp larva live in the same host individual

Adult small intestine

Larva striated muscle

44

10302017

23

Trichinella spiralis larvae in

muscle section 45 A higher power magnification

Larva of Trichinella spiralis

46

10302017

24

47

Life Cycle of T spiralis

Trichinellosis is acquired by ingesting meat containing cysts

(encysted larvae) of Trichinella

After exposure to gastric acid and pepsin the larvae are

released from the cysts and invade the small bowel mucosa

where they develop into adult worms

(female 22 mm in length males 12 mm life span in the

small bowel 4 weeks)

After 1 week the females release larvae that migrate to the

striated muscles where they encyst

Encystment is completed in 4 to 5 weeks and the encysted

larvae may remain viable for several years 48

10302017

25

Ingestion of the encysted larvae perpetuates the

cycle

Rats and rodents are primarily responsible for

maintaining the endemicity of this infection

Carnivorousomnivorous animals such as pigs or

bears feed on infected rodents or meat from other

animals

Humans are accidentally infected when eating

improperly processed meat of these carnivorous

animals (or eating food contaminated with such

meat)

49

Main Points of Life Cycle

Infective stage capsulated larva

Infection route eating raw or improperly cooked pork

or its products

No extra-hostal developing but must change host to

finish the life cycle exists many reservoir host

Human acts as IH and DH

50

10302017

26

Pathogenesis

Main pathogenic factor larva

Invasion stage (intestinal phase) minor digestive

disturbance

Migration stage (muscular phase) diarrhea myalgias

abdominal pain vomiting weakness blood eosinophilia

circumorbital edema myositis Muscular tenderness

Encystment stage recovery

51

Epidemiologiy

Cosmopolitan esp in Europe and North-America

China due to raw pork consumption

52

Diagnosis

Based on the basis of clinical symptoms and history and

eosinophilia

Etiological diagnosis

Biopsy of skeletal muscle

Immunological diagnosis (antibody detection)

10302017

27

Control methods

Hygienic education

Properly cooking pork

Low temperature storage of pork

(all larvae are killed at -15ordmC for 24hs)

Scientific raising pigs heat treatment of garbage used as pig

food

53

10302017

9

Characteristic of life cycle

bull Host Mosqutoes (intermediate host)

Human (final host)

bull Location Lymphatics and lymph nodes

bull Infective stage Infective larvae

bull Transmission stage Microfilariae

bull Diagnostic stage Microfilariae

Lymphatic filariasis often consists of

asymptomatic microfilaremia

Some patients develop lymphatic dysfunction

causing lymphedema and elephantiasis(in limb or

scrotum)

Pulmonary tropical eosinophilia syndrome with

nocturnal cough and wheezing fever and

eosinophilia

10302017

10

Location (adult) lymphatic system Wb superficial and deeper

eg lower limbs groin scrotum etc

Bm superficial eg mainly in lower limbs

Infective stage filariform larva

Infection route mosquito inoculation

Discharge stage microfilaria

19

Intermediate host amp vector mosquito

Wb Culex (Anopheles)

Bm Anopheles (Aedes)

Mf show nocturnal periodicity

Nocturnal periodicity

Mfs appear in the peripheral blood in high density during the

night but hide in the pulmonary capillaries during the daytime

while the host is awaken

Wb 10 Pm ~ 2 Am

Bm 8 Pm ~ 4 Am

20

10302017

11

Lymphatic filariasis elephantiasis is the last

consequence of the swelling of limbs and scrotum

21

Early hydrocoel in a Tanzanian man with W bancrofti infection 22

10302017

12

Lymphatic filariasis elephantiasis of scrotum

Genital manifestations are frequent in W bancrofti

infections while they are rare during Bmalayi infections

23

elephantiasis Hydrocele testis

24

10302017

13

Laboratory Diagnosis of lymphatic filaria

Etiological examination

Stained thick blood smear first choice of

methods

Blood drop microscopy used in the field

Lymph node biopsy

25

Loa loa (Loaiasis or Loiasis)

(The African Eye Worm)

Distribution West and Central parts of tropical Africa

Adult Morphology as described before in the

introduction of filaria but with tuberculated

cuticle at both ends

10302017

14

Life cycle Habitat

1 Subcutaneous tissues of man free

migrating in chest back scalp axilla

groin and may be seen under the

conjunctiva

(hence the common name eye worm)

Life cycle of Loa loa

10302017

15

2 Intermediate host (vector) Female Chrysops fly (Deer fly) day biting insect (transmission as in W Bancrofi )

3 Reservoir host Monkeys 4 The infective stage is the filariform

larvae in the mouth of chrysops

5 The Microfilaria has the following characters

250 x 5

The sheath is tight

body curves are kinky

The tail is S-shaped and full of nuclei

The periodicity is diurnal with

maximum at noon

10302017

16

Microfilaria of Loa loa

Pathogenesis amp Symptomatology

Disease Loiasis Loaiasis

Wandering of adult worms may be observed in loose

connective tissues such as eye lids conjunctiva breast

amp scrotum creeping sensation irritation and

itching congestion and oedema of eye lids

It can be seen moving under the conjunctiva or

crossing the bridge of the nose but it doesnrsquot cause

blindness

10302017

17

Loiasis of the eye

2 Calabar swellings allergic reaction to worm

metabolites It is named after a town in Eastern

Nigeria

It is a transient swelling appears suddenly and

disappears gradually within 2-3 days without

suppuration

The commonest sites are forearm hands wrist

elbows and ankle It is due to hypersensitivity

(allergic reaction) to the adult worms

microfilariae and their toxic metabolites

10302017

18

3 Complications are due to invasion of the worms to

ectopic foci causing encephalopathy due to

involvement of CNS where microfilariae can be

detected in cerebrospinal fluid (CSF)

4 Arthritis Acute arthritis with joint effusion may occur

5 Also hydrocele glomerulonephritis endomyocardial

fibrosis and retinopathy can occur

Diagnosis

1 Clinical By observing the adult worm crossing

the bridge of the nose or under the conjunctiva

together with history of calabar swelling

2 Laboratory Blood examination a drop of the

peripheral blood is taken during the day time

(10 am to 2 pm) and is examined fresh for

motile microfilariae and stained thick smear

for fixed microfilariae

10302017

19

3 History of calabar swelling

4 Serological and intradermal test

5 Eosinophiliaamp leucocytosis

Control

Treatment of infected persons

Protection by screening or by fly repellents when

visiting forests in endemic area

Chrysops control is difficult because it breeds in

swampy areas of forest

10302017

20

Laboratory Diagnosis of filaria

Identification of microfilariae by microscopic examination is the most

practical diagnostic procedure

Examination of blood samples will allow identification of microfilariae

of Wuchereria bancrofti Brugia malayi Loa loa Mansonella perstans and M

ozzardi

It is important to time the blood collection with the known

periodicity of the microfilariae

The blood sample can be a thick smear stained with Giemsa or

hematoxylin and eosin For increased sensitivity concentration

techniques can be used

These include centrifugation of the blood sample lyzed in 2 formalin

(Knotts technique) or filtration through a Nucleopore membrane

39

Examination of skin snips will identify microfilariae

of Onchocerca volvulus and Mansonella streptocerca Skin

snips can be obtained using a corneal-scleral punch or

more simply a scalpel and needle The sample must be

allowed to incubate for 30 minutes to 2 hours in saline or

culture medium

Antigen detection using an immunoassay for

circulating filarial antigens constitutes a useful

diagnostic approach because microfilaremia can be

low and variable A rapid-format

immunochromatographic test

40

10302017

21

Molecular diagnosis using PCR is available for W bancrofti

and B malayi

1048707 Identification of adult worms is possible from tissue samples collected during nodulectomies (onchocerciasis) or

during subcutaneous biopsies or worm removal from the eye

(loiasis)

1048707 Antibody detection is of limited value Substantial antigenic cross reactivity exists between filaria and other

helminths and a positive serologic test does not distinguish

between past and current infection

41

42

a Infection with

Wuchereria bancrofti

elephantiasis

b infection with Loa

loa eyelid swelling

c onchocercosis

cutaneous nodules

caused by Onchocerca

volvulus

d blindness caused by

O volvulus

e Trichinella spiralis

larvae in rat

musculature

f larva migrans

externa

10302017

22

Trichina worm Trichinella spiralis

43

و ونحى انخزير )قال تعانى بسى هللا انرح انرحيى يتة وانذ و عهيكى ان ا حر إ

حيى غفور ر هللا اضطر غير باغ ول عاد فإ به ف (ويا أهم نغير هللا

115اآليــة -انحم

Biological characteristics

Zoonosis

Ovoviviparous

Adult amp larva live in the same host individual

Adult small intestine

Larva striated muscle

44

10302017

23

Trichinella spiralis larvae in

muscle section 45 A higher power magnification

Larva of Trichinella spiralis

46

10302017

24

47

Life Cycle of T spiralis

Trichinellosis is acquired by ingesting meat containing cysts

(encysted larvae) of Trichinella

After exposure to gastric acid and pepsin the larvae are

released from the cysts and invade the small bowel mucosa

where they develop into adult worms

(female 22 mm in length males 12 mm life span in the

small bowel 4 weeks)

After 1 week the females release larvae that migrate to the

striated muscles where they encyst

Encystment is completed in 4 to 5 weeks and the encysted

larvae may remain viable for several years 48

10302017

25

Ingestion of the encysted larvae perpetuates the

cycle

Rats and rodents are primarily responsible for

maintaining the endemicity of this infection

Carnivorousomnivorous animals such as pigs or

bears feed on infected rodents or meat from other

animals

Humans are accidentally infected when eating

improperly processed meat of these carnivorous

animals (or eating food contaminated with such

meat)

49

Main Points of Life Cycle

Infective stage capsulated larva

Infection route eating raw or improperly cooked pork

or its products

No extra-hostal developing but must change host to

finish the life cycle exists many reservoir host

Human acts as IH and DH

50

10302017

26

Pathogenesis

Main pathogenic factor larva

Invasion stage (intestinal phase) minor digestive

disturbance

Migration stage (muscular phase) diarrhea myalgias

abdominal pain vomiting weakness blood eosinophilia

circumorbital edema myositis Muscular tenderness

Encystment stage recovery

51

Epidemiologiy

Cosmopolitan esp in Europe and North-America

China due to raw pork consumption

52

Diagnosis

Based on the basis of clinical symptoms and history and

eosinophilia

Etiological diagnosis

Biopsy of skeletal muscle

Immunological diagnosis (antibody detection)

10302017

27

Control methods

Hygienic education

Properly cooking pork

Low temperature storage of pork

(all larvae are killed at -15ordmC for 24hs)

Scientific raising pigs heat treatment of garbage used as pig

food

53

10302017

10

Location (adult) lymphatic system Wb superficial and deeper

eg lower limbs groin scrotum etc

Bm superficial eg mainly in lower limbs

Infective stage filariform larva

Infection route mosquito inoculation

Discharge stage microfilaria

19

Intermediate host amp vector mosquito

Wb Culex (Anopheles)

Bm Anopheles (Aedes)

Mf show nocturnal periodicity

Nocturnal periodicity

Mfs appear in the peripheral blood in high density during the

night but hide in the pulmonary capillaries during the daytime

while the host is awaken

Wb 10 Pm ~ 2 Am

Bm 8 Pm ~ 4 Am

20

10302017

11

Lymphatic filariasis elephantiasis is the last

consequence of the swelling of limbs and scrotum

21

Early hydrocoel in a Tanzanian man with W bancrofti infection 22

10302017

12

Lymphatic filariasis elephantiasis of scrotum

Genital manifestations are frequent in W bancrofti

infections while they are rare during Bmalayi infections

23

elephantiasis Hydrocele testis

24

10302017

13

Laboratory Diagnosis of lymphatic filaria

Etiological examination

Stained thick blood smear first choice of

methods

Blood drop microscopy used in the field

Lymph node biopsy

25

Loa loa (Loaiasis or Loiasis)

(The African Eye Worm)

Distribution West and Central parts of tropical Africa

Adult Morphology as described before in the

introduction of filaria but with tuberculated

cuticle at both ends

10302017

14

Life cycle Habitat

1 Subcutaneous tissues of man free

migrating in chest back scalp axilla

groin and may be seen under the

conjunctiva

(hence the common name eye worm)

Life cycle of Loa loa

10302017

15

2 Intermediate host (vector) Female Chrysops fly (Deer fly) day biting insect (transmission as in W Bancrofi )

3 Reservoir host Monkeys 4 The infective stage is the filariform

larvae in the mouth of chrysops

5 The Microfilaria has the following characters

250 x 5

The sheath is tight

body curves are kinky

The tail is S-shaped and full of nuclei

The periodicity is diurnal with

maximum at noon

10302017

16

Microfilaria of Loa loa

Pathogenesis amp Symptomatology

Disease Loiasis Loaiasis

Wandering of adult worms may be observed in loose

connective tissues such as eye lids conjunctiva breast

amp scrotum creeping sensation irritation and

itching congestion and oedema of eye lids

It can be seen moving under the conjunctiva or

crossing the bridge of the nose but it doesnrsquot cause

blindness

10302017

17

Loiasis of the eye

2 Calabar swellings allergic reaction to worm

metabolites It is named after a town in Eastern

Nigeria

It is a transient swelling appears suddenly and

disappears gradually within 2-3 days without

suppuration

The commonest sites are forearm hands wrist

elbows and ankle It is due to hypersensitivity

(allergic reaction) to the adult worms

microfilariae and their toxic metabolites

10302017

18

3 Complications are due to invasion of the worms to

ectopic foci causing encephalopathy due to

involvement of CNS where microfilariae can be

detected in cerebrospinal fluid (CSF)

4 Arthritis Acute arthritis with joint effusion may occur

5 Also hydrocele glomerulonephritis endomyocardial

fibrosis and retinopathy can occur

Diagnosis

1 Clinical By observing the adult worm crossing

the bridge of the nose or under the conjunctiva

together with history of calabar swelling

2 Laboratory Blood examination a drop of the

peripheral blood is taken during the day time

(10 am to 2 pm) and is examined fresh for

motile microfilariae and stained thick smear

for fixed microfilariae

10302017

19

3 History of calabar swelling

4 Serological and intradermal test

5 Eosinophiliaamp leucocytosis

Control

Treatment of infected persons

Protection by screening or by fly repellents when

visiting forests in endemic area

Chrysops control is difficult because it breeds in

swampy areas of forest

10302017

20

Laboratory Diagnosis of filaria

Identification of microfilariae by microscopic examination is the most

practical diagnostic procedure

Examination of blood samples will allow identification of microfilariae

of Wuchereria bancrofti Brugia malayi Loa loa Mansonella perstans and M

ozzardi

It is important to time the blood collection with the known

periodicity of the microfilariae

The blood sample can be a thick smear stained with Giemsa or

hematoxylin and eosin For increased sensitivity concentration

techniques can be used

These include centrifugation of the blood sample lyzed in 2 formalin

(Knotts technique) or filtration through a Nucleopore membrane

39

Examination of skin snips will identify microfilariae

of Onchocerca volvulus and Mansonella streptocerca Skin

snips can be obtained using a corneal-scleral punch or

more simply a scalpel and needle The sample must be

allowed to incubate for 30 minutes to 2 hours in saline or

culture medium

Antigen detection using an immunoassay for

circulating filarial antigens constitutes a useful

diagnostic approach because microfilaremia can be

low and variable A rapid-format

immunochromatographic test

40

10302017

21

Molecular diagnosis using PCR is available for W bancrofti

and B malayi

1048707 Identification of adult worms is possible from tissue samples collected during nodulectomies (onchocerciasis) or

during subcutaneous biopsies or worm removal from the eye

(loiasis)

1048707 Antibody detection is of limited value Substantial antigenic cross reactivity exists between filaria and other

helminths and a positive serologic test does not distinguish

between past and current infection

41

42

a Infection with

Wuchereria bancrofti

elephantiasis

b infection with Loa

loa eyelid swelling

c onchocercosis

cutaneous nodules

caused by Onchocerca

volvulus

d blindness caused by

O volvulus

e Trichinella spiralis

larvae in rat

musculature

f larva migrans

externa

10302017

22

Trichina worm Trichinella spiralis

43

و ونحى انخزير )قال تعانى بسى هللا انرح انرحيى يتة وانذ و عهيكى ان ا حر إ

حيى غفور ر هللا اضطر غير باغ ول عاد فإ به ف (ويا أهم نغير هللا

115اآليــة -انحم

Biological characteristics

Zoonosis

Ovoviviparous

Adult amp larva live in the same host individual

Adult small intestine

Larva striated muscle

44

10302017

23

Trichinella spiralis larvae in

muscle section 45 A higher power magnification

Larva of Trichinella spiralis

46

10302017

24

47

Life Cycle of T spiralis

Trichinellosis is acquired by ingesting meat containing cysts

(encysted larvae) of Trichinella

After exposure to gastric acid and pepsin the larvae are

released from the cysts and invade the small bowel mucosa

where they develop into adult worms

(female 22 mm in length males 12 mm life span in the

small bowel 4 weeks)

After 1 week the females release larvae that migrate to the

striated muscles where they encyst

Encystment is completed in 4 to 5 weeks and the encysted

larvae may remain viable for several years 48

10302017

25

Ingestion of the encysted larvae perpetuates the

cycle

Rats and rodents are primarily responsible for

maintaining the endemicity of this infection

Carnivorousomnivorous animals such as pigs or

bears feed on infected rodents or meat from other

animals

Humans are accidentally infected when eating

improperly processed meat of these carnivorous

animals (or eating food contaminated with such

meat)

49

Main Points of Life Cycle

Infective stage capsulated larva

Infection route eating raw or improperly cooked pork

or its products

No extra-hostal developing but must change host to

finish the life cycle exists many reservoir host

Human acts as IH and DH

50

10302017

26

Pathogenesis

Main pathogenic factor larva

Invasion stage (intestinal phase) minor digestive

disturbance

Migration stage (muscular phase) diarrhea myalgias

abdominal pain vomiting weakness blood eosinophilia

circumorbital edema myositis Muscular tenderness

Encystment stage recovery

51

Epidemiologiy

Cosmopolitan esp in Europe and North-America

China due to raw pork consumption

52

Diagnosis

Based on the basis of clinical symptoms and history and

eosinophilia

Etiological diagnosis

Biopsy of skeletal muscle

Immunological diagnosis (antibody detection)

10302017

27

Control methods

Hygienic education

Properly cooking pork

Low temperature storage of pork

(all larvae are killed at -15ordmC for 24hs)

Scientific raising pigs heat treatment of garbage used as pig

food

53

10302017

11

Lymphatic filariasis elephantiasis is the last

consequence of the swelling of limbs and scrotum

21

Early hydrocoel in a Tanzanian man with W bancrofti infection 22

10302017

12

Lymphatic filariasis elephantiasis of scrotum

Genital manifestations are frequent in W bancrofti

infections while they are rare during Bmalayi infections

23

elephantiasis Hydrocele testis

24

10302017

13

Laboratory Diagnosis of lymphatic filaria

Etiological examination

Stained thick blood smear first choice of

methods

Blood drop microscopy used in the field

Lymph node biopsy

25

Loa loa (Loaiasis or Loiasis)

(The African Eye Worm)

Distribution West and Central parts of tropical Africa

Adult Morphology as described before in the

introduction of filaria but with tuberculated

cuticle at both ends

10302017

14

Life cycle Habitat

1 Subcutaneous tissues of man free

migrating in chest back scalp axilla

groin and may be seen under the

conjunctiva

(hence the common name eye worm)

Life cycle of Loa loa

10302017

15

2 Intermediate host (vector) Female Chrysops fly (Deer fly) day biting insect (transmission as in W Bancrofi )

3 Reservoir host Monkeys 4 The infective stage is the filariform

larvae in the mouth of chrysops

5 The Microfilaria has the following characters

250 x 5

The sheath is tight

body curves are kinky

The tail is S-shaped and full of nuclei

The periodicity is diurnal with

maximum at noon

10302017

16

Microfilaria of Loa loa

Pathogenesis amp Symptomatology

Disease Loiasis Loaiasis

Wandering of adult worms may be observed in loose

connective tissues such as eye lids conjunctiva breast

amp scrotum creeping sensation irritation and

itching congestion and oedema of eye lids

It can be seen moving under the conjunctiva or

crossing the bridge of the nose but it doesnrsquot cause

blindness

10302017

17

Loiasis of the eye

2 Calabar swellings allergic reaction to worm

metabolites It is named after a town in Eastern

Nigeria

It is a transient swelling appears suddenly and

disappears gradually within 2-3 days without

suppuration

The commonest sites are forearm hands wrist

elbows and ankle It is due to hypersensitivity

(allergic reaction) to the adult worms

microfilariae and their toxic metabolites

10302017

18

3 Complications are due to invasion of the worms to

ectopic foci causing encephalopathy due to

involvement of CNS where microfilariae can be

detected in cerebrospinal fluid (CSF)

4 Arthritis Acute arthritis with joint effusion may occur

5 Also hydrocele glomerulonephritis endomyocardial

fibrosis and retinopathy can occur

Diagnosis

1 Clinical By observing the adult worm crossing

the bridge of the nose or under the conjunctiva

together with history of calabar swelling

2 Laboratory Blood examination a drop of the

peripheral blood is taken during the day time

(10 am to 2 pm) and is examined fresh for

motile microfilariae and stained thick smear

for fixed microfilariae

10302017

19

3 History of calabar swelling

4 Serological and intradermal test

5 Eosinophiliaamp leucocytosis

Control

Treatment of infected persons

Protection by screening or by fly repellents when

visiting forests in endemic area

Chrysops control is difficult because it breeds in

swampy areas of forest

10302017

20

Laboratory Diagnosis of filaria

Identification of microfilariae by microscopic examination is the most

practical diagnostic procedure

Examination of blood samples will allow identification of microfilariae

of Wuchereria bancrofti Brugia malayi Loa loa Mansonella perstans and M

ozzardi

It is important to time the blood collection with the known

periodicity of the microfilariae

The blood sample can be a thick smear stained with Giemsa or

hematoxylin and eosin For increased sensitivity concentration

techniques can be used

These include centrifugation of the blood sample lyzed in 2 formalin

(Knotts technique) or filtration through a Nucleopore membrane

39

Examination of skin snips will identify microfilariae

of Onchocerca volvulus and Mansonella streptocerca Skin

snips can be obtained using a corneal-scleral punch or

more simply a scalpel and needle The sample must be

allowed to incubate for 30 minutes to 2 hours in saline or

culture medium

Antigen detection using an immunoassay for

circulating filarial antigens constitutes a useful

diagnostic approach because microfilaremia can be

low and variable A rapid-format

immunochromatographic test

40

10302017

21

Molecular diagnosis using PCR is available for W bancrofti

and B malayi

1048707 Identification of adult worms is possible from tissue samples collected during nodulectomies (onchocerciasis) or

during subcutaneous biopsies or worm removal from the eye

(loiasis)

1048707 Antibody detection is of limited value Substantial antigenic cross reactivity exists between filaria and other

helminths and a positive serologic test does not distinguish

between past and current infection

41

42

a Infection with

Wuchereria bancrofti

elephantiasis

b infection with Loa

loa eyelid swelling

c onchocercosis

cutaneous nodules

caused by Onchocerca

volvulus

d blindness caused by

O volvulus

e Trichinella spiralis

larvae in rat

musculature

f larva migrans

externa

10302017

22

Trichina worm Trichinella spiralis

43

و ونحى انخزير )قال تعانى بسى هللا انرح انرحيى يتة وانذ و عهيكى ان ا حر إ

حيى غفور ر هللا اضطر غير باغ ول عاد فإ به ف (ويا أهم نغير هللا

115اآليــة -انحم

Biological characteristics

Zoonosis

Ovoviviparous

Adult amp larva live in the same host individual

Adult small intestine

Larva striated muscle

44

10302017

23

Trichinella spiralis larvae in

muscle section 45 A higher power magnification

Larva of Trichinella spiralis

46

10302017

24

47

Life Cycle of T spiralis

Trichinellosis is acquired by ingesting meat containing cysts

(encysted larvae) of Trichinella

After exposure to gastric acid and pepsin the larvae are

released from the cysts and invade the small bowel mucosa

where they develop into adult worms

(female 22 mm in length males 12 mm life span in the

small bowel 4 weeks)

After 1 week the females release larvae that migrate to the

striated muscles where they encyst

Encystment is completed in 4 to 5 weeks and the encysted

larvae may remain viable for several years 48

10302017

25

Ingestion of the encysted larvae perpetuates the

cycle

Rats and rodents are primarily responsible for

maintaining the endemicity of this infection

Carnivorousomnivorous animals such as pigs or

bears feed on infected rodents or meat from other

animals

Humans are accidentally infected when eating

improperly processed meat of these carnivorous

animals (or eating food contaminated with such

meat)

49

Main Points of Life Cycle

Infective stage capsulated larva

Infection route eating raw or improperly cooked pork

or its products

No extra-hostal developing but must change host to

finish the life cycle exists many reservoir host

Human acts as IH and DH

50

10302017

26

Pathogenesis

Main pathogenic factor larva

Invasion stage (intestinal phase) minor digestive

disturbance

Migration stage (muscular phase) diarrhea myalgias

abdominal pain vomiting weakness blood eosinophilia

circumorbital edema myositis Muscular tenderness

Encystment stage recovery

51

Epidemiologiy

Cosmopolitan esp in Europe and North-America

China due to raw pork consumption

52

Diagnosis

Based on the basis of clinical symptoms and history and

eosinophilia

Etiological diagnosis

Biopsy of skeletal muscle

Immunological diagnosis (antibody detection)

10302017

27

Control methods

Hygienic education

Properly cooking pork

Low temperature storage of pork

(all larvae are killed at -15ordmC for 24hs)

Scientific raising pigs heat treatment of garbage used as pig

food

53

10302017

12

Lymphatic filariasis elephantiasis of scrotum

Genital manifestations are frequent in W bancrofti

infections while they are rare during Bmalayi infections

23

elephantiasis Hydrocele testis

24

10302017

13

Laboratory Diagnosis of lymphatic filaria

Etiological examination

Stained thick blood smear first choice of

methods

Blood drop microscopy used in the field

Lymph node biopsy

25

Loa loa (Loaiasis or Loiasis)

(The African Eye Worm)

Distribution West and Central parts of tropical Africa

Adult Morphology as described before in the

introduction of filaria but with tuberculated

cuticle at both ends

10302017

14

Life cycle Habitat

1 Subcutaneous tissues of man free

migrating in chest back scalp axilla

groin and may be seen under the

conjunctiva

(hence the common name eye worm)

Life cycle of Loa loa

10302017

15

2 Intermediate host (vector) Female Chrysops fly (Deer fly) day biting insect (transmission as in W Bancrofi )

3 Reservoir host Monkeys 4 The infective stage is the filariform

larvae in the mouth of chrysops

5 The Microfilaria has the following characters

250 x 5

The sheath is tight

body curves are kinky

The tail is S-shaped and full of nuclei

The periodicity is diurnal with

maximum at noon

10302017

16

Microfilaria of Loa loa

Pathogenesis amp Symptomatology

Disease Loiasis Loaiasis

Wandering of adult worms may be observed in loose

connective tissues such as eye lids conjunctiva breast

amp scrotum creeping sensation irritation and

itching congestion and oedema of eye lids

It can be seen moving under the conjunctiva or

crossing the bridge of the nose but it doesnrsquot cause

blindness

10302017

17

Loiasis of the eye

2 Calabar swellings allergic reaction to worm

metabolites It is named after a town in Eastern

Nigeria

It is a transient swelling appears suddenly and

disappears gradually within 2-3 days without

suppuration

The commonest sites are forearm hands wrist

elbows and ankle It is due to hypersensitivity

(allergic reaction) to the adult worms

microfilariae and their toxic metabolites

10302017

18

3 Complications are due to invasion of the worms to

ectopic foci causing encephalopathy due to

involvement of CNS where microfilariae can be

detected in cerebrospinal fluid (CSF)

4 Arthritis Acute arthritis with joint effusion may occur

5 Also hydrocele glomerulonephritis endomyocardial

fibrosis and retinopathy can occur

Diagnosis

1 Clinical By observing the adult worm crossing

the bridge of the nose or under the conjunctiva

together with history of calabar swelling

2 Laboratory Blood examination a drop of the

peripheral blood is taken during the day time

(10 am to 2 pm) and is examined fresh for

motile microfilariae and stained thick smear

for fixed microfilariae

10302017

19

3 History of calabar swelling

4 Serological and intradermal test

5 Eosinophiliaamp leucocytosis

Control

Treatment of infected persons

Protection by screening or by fly repellents when

visiting forests in endemic area

Chrysops control is difficult because it breeds in

swampy areas of forest

10302017

20

Laboratory Diagnosis of filaria

Identification of microfilariae by microscopic examination is the most

practical diagnostic procedure

Examination of blood samples will allow identification of microfilariae

of Wuchereria bancrofti Brugia malayi Loa loa Mansonella perstans and M

ozzardi

It is important to time the blood collection with the known

periodicity of the microfilariae

The blood sample can be a thick smear stained with Giemsa or

hematoxylin and eosin For increased sensitivity concentration

techniques can be used

These include centrifugation of the blood sample lyzed in 2 formalin

(Knotts technique) or filtration through a Nucleopore membrane

39

Examination of skin snips will identify microfilariae

of Onchocerca volvulus and Mansonella streptocerca Skin

snips can be obtained using a corneal-scleral punch or

more simply a scalpel and needle The sample must be

allowed to incubate for 30 minutes to 2 hours in saline or

culture medium

Antigen detection using an immunoassay for

circulating filarial antigens constitutes a useful

diagnostic approach because microfilaremia can be

low and variable A rapid-format

immunochromatographic test

40

10302017

21

Molecular diagnosis using PCR is available for W bancrofti

and B malayi

1048707 Identification of adult worms is possible from tissue samples collected during nodulectomies (onchocerciasis) or

during subcutaneous biopsies or worm removal from the eye

(loiasis)

1048707 Antibody detection is of limited value Substantial antigenic cross reactivity exists between filaria and other

helminths and a positive serologic test does not distinguish

between past and current infection

41

42

a Infection with

Wuchereria bancrofti

elephantiasis

b infection with Loa

loa eyelid swelling

c onchocercosis

cutaneous nodules

caused by Onchocerca

volvulus

d blindness caused by

O volvulus

e Trichinella spiralis

larvae in rat

musculature

f larva migrans

externa

10302017

22

Trichina worm Trichinella spiralis

43

و ونحى انخزير )قال تعانى بسى هللا انرح انرحيى يتة وانذ و عهيكى ان ا حر إ

حيى غفور ر هللا اضطر غير باغ ول عاد فإ به ف (ويا أهم نغير هللا

115اآليــة -انحم

Biological characteristics

Zoonosis

Ovoviviparous

Adult amp larva live in the same host individual

Adult small intestine

Larva striated muscle

44

10302017

23

Trichinella spiralis larvae in

muscle section 45 A higher power magnification

Larva of Trichinella spiralis

46

10302017

24

47

Life Cycle of T spiralis

Trichinellosis is acquired by ingesting meat containing cysts

(encysted larvae) of Trichinella

After exposure to gastric acid and pepsin the larvae are

released from the cysts and invade the small bowel mucosa

where they develop into adult worms

(female 22 mm in length males 12 mm life span in the

small bowel 4 weeks)

After 1 week the females release larvae that migrate to the

striated muscles where they encyst

Encystment is completed in 4 to 5 weeks and the encysted

larvae may remain viable for several years 48

10302017

25

Ingestion of the encysted larvae perpetuates the

cycle

Rats and rodents are primarily responsible for

maintaining the endemicity of this infection

Carnivorousomnivorous animals such as pigs or

bears feed on infected rodents or meat from other

animals

Humans are accidentally infected when eating

improperly processed meat of these carnivorous

animals (or eating food contaminated with such

meat)

49

Main Points of Life Cycle

Infective stage capsulated larva

Infection route eating raw or improperly cooked pork

or its products

No extra-hostal developing but must change host to

finish the life cycle exists many reservoir host

Human acts as IH and DH

50

10302017

26

Pathogenesis

Main pathogenic factor larva

Invasion stage (intestinal phase) minor digestive

disturbance

Migration stage (muscular phase) diarrhea myalgias

abdominal pain vomiting weakness blood eosinophilia

circumorbital edema myositis Muscular tenderness

Encystment stage recovery

51

Epidemiologiy

Cosmopolitan esp in Europe and North-America

China due to raw pork consumption

52

Diagnosis

Based on the basis of clinical symptoms and history and

eosinophilia

Etiological diagnosis

Biopsy of skeletal muscle

Immunological diagnosis (antibody detection)

10302017

27

Control methods

Hygienic education

Properly cooking pork

Low temperature storage of pork

(all larvae are killed at -15ordmC for 24hs)

Scientific raising pigs heat treatment of garbage used as pig

food

53

10302017

13

Laboratory Diagnosis of lymphatic filaria

Etiological examination

Stained thick blood smear first choice of

methods

Blood drop microscopy used in the field

Lymph node biopsy

25

Loa loa (Loaiasis or Loiasis)

(The African Eye Worm)

Distribution West and Central parts of tropical Africa

Adult Morphology as described before in the

introduction of filaria but with tuberculated

cuticle at both ends

10302017

14

Life cycle Habitat

1 Subcutaneous tissues of man free

migrating in chest back scalp axilla

groin and may be seen under the

conjunctiva

(hence the common name eye worm)

Life cycle of Loa loa

10302017

15

2 Intermediate host (vector) Female Chrysops fly (Deer fly) day biting insect (transmission as in W Bancrofi )

3 Reservoir host Monkeys 4 The infective stage is the filariform

larvae in the mouth of chrysops

5 The Microfilaria has the following characters

250 x 5

The sheath is tight

body curves are kinky

The tail is S-shaped and full of nuclei

The periodicity is diurnal with

maximum at noon

10302017

16

Microfilaria of Loa loa

Pathogenesis amp Symptomatology

Disease Loiasis Loaiasis

Wandering of adult worms may be observed in loose

connective tissues such as eye lids conjunctiva breast

amp scrotum creeping sensation irritation and

itching congestion and oedema of eye lids

It can be seen moving under the conjunctiva or

crossing the bridge of the nose but it doesnrsquot cause

blindness

10302017

17

Loiasis of the eye

2 Calabar swellings allergic reaction to worm

metabolites It is named after a town in Eastern

Nigeria

It is a transient swelling appears suddenly and

disappears gradually within 2-3 days without

suppuration

The commonest sites are forearm hands wrist

elbows and ankle It is due to hypersensitivity

(allergic reaction) to the adult worms

microfilariae and their toxic metabolites

10302017

18

3 Complications are due to invasion of the worms to

ectopic foci causing encephalopathy due to

involvement of CNS where microfilariae can be

detected in cerebrospinal fluid (CSF)

4 Arthritis Acute arthritis with joint effusion may occur

5 Also hydrocele glomerulonephritis endomyocardial

fibrosis and retinopathy can occur

Diagnosis

1 Clinical By observing the adult worm crossing

the bridge of the nose or under the conjunctiva

together with history of calabar swelling

2 Laboratory Blood examination a drop of the

peripheral blood is taken during the day time

(10 am to 2 pm) and is examined fresh for

motile microfilariae and stained thick smear

for fixed microfilariae

10302017

19

3 History of calabar swelling

4 Serological and intradermal test

5 Eosinophiliaamp leucocytosis

Control

Treatment of infected persons

Protection by screening or by fly repellents when

visiting forests in endemic area

Chrysops control is difficult because it breeds in

swampy areas of forest

10302017

20

Laboratory Diagnosis of filaria

Identification of microfilariae by microscopic examination is the most

practical diagnostic procedure

Examination of blood samples will allow identification of microfilariae

of Wuchereria bancrofti Brugia malayi Loa loa Mansonella perstans and M

ozzardi

It is important to time the blood collection with the known

periodicity of the microfilariae

The blood sample can be a thick smear stained with Giemsa or

hematoxylin and eosin For increased sensitivity concentration

techniques can be used

These include centrifugation of the blood sample lyzed in 2 formalin

(Knotts technique) or filtration through a Nucleopore membrane

39

Examination of skin snips will identify microfilariae

of Onchocerca volvulus and Mansonella streptocerca Skin

snips can be obtained using a corneal-scleral punch or

more simply a scalpel and needle The sample must be

allowed to incubate for 30 minutes to 2 hours in saline or

culture medium

Antigen detection using an immunoassay for

circulating filarial antigens constitutes a useful

diagnostic approach because microfilaremia can be

low and variable A rapid-format

immunochromatographic test

40

10302017

21

Molecular diagnosis using PCR is available for W bancrofti

and B malayi

1048707 Identification of adult worms is possible from tissue samples collected during nodulectomies (onchocerciasis) or

during subcutaneous biopsies or worm removal from the eye

(loiasis)

1048707 Antibody detection is of limited value Substantial antigenic cross reactivity exists between filaria and other

helminths and a positive serologic test does not distinguish

between past and current infection

41

42

a Infection with

Wuchereria bancrofti

elephantiasis

b infection with Loa

loa eyelid swelling

c onchocercosis

cutaneous nodules

caused by Onchocerca

volvulus

d blindness caused by

O volvulus

e Trichinella spiralis

larvae in rat

musculature

f larva migrans

externa

10302017

22

Trichina worm Trichinella spiralis

43

و ونحى انخزير )قال تعانى بسى هللا انرح انرحيى يتة وانذ و عهيكى ان ا حر إ

حيى غفور ر هللا اضطر غير باغ ول عاد فإ به ف (ويا أهم نغير هللا

115اآليــة -انحم

Biological characteristics

Zoonosis

Ovoviviparous

Adult amp larva live in the same host individual

Adult small intestine

Larva striated muscle

44

10302017

23

Trichinella spiralis larvae in

muscle section 45 A higher power magnification

Larva of Trichinella spiralis

46

10302017

24

47

Life Cycle of T spiralis

Trichinellosis is acquired by ingesting meat containing cysts

(encysted larvae) of Trichinella

After exposure to gastric acid and pepsin the larvae are

released from the cysts and invade the small bowel mucosa

where they develop into adult worms

(female 22 mm in length males 12 mm life span in the

small bowel 4 weeks)

After 1 week the females release larvae that migrate to the

striated muscles where they encyst

Encystment is completed in 4 to 5 weeks and the encysted

larvae may remain viable for several years 48

10302017

25

Ingestion of the encysted larvae perpetuates the

cycle

Rats and rodents are primarily responsible for

maintaining the endemicity of this infection

Carnivorousomnivorous animals such as pigs or

bears feed on infected rodents or meat from other

animals

Humans are accidentally infected when eating

improperly processed meat of these carnivorous

animals (or eating food contaminated with such

meat)

49

Main Points of Life Cycle

Infective stage capsulated larva

Infection route eating raw or improperly cooked pork

or its products

No extra-hostal developing but must change host to

finish the life cycle exists many reservoir host

Human acts as IH and DH

50

10302017

26

Pathogenesis

Main pathogenic factor larva

Invasion stage (intestinal phase) minor digestive

disturbance

Migration stage (muscular phase) diarrhea myalgias

abdominal pain vomiting weakness blood eosinophilia

circumorbital edema myositis Muscular tenderness

Encystment stage recovery

51

Epidemiologiy

Cosmopolitan esp in Europe and North-America

China due to raw pork consumption

52

Diagnosis

Based on the basis of clinical symptoms and history and

eosinophilia

Etiological diagnosis

Biopsy of skeletal muscle

Immunological diagnosis (antibody detection)

10302017

27

Control methods

Hygienic education

Properly cooking pork

Low temperature storage of pork

(all larvae are killed at -15ordmC for 24hs)

Scientific raising pigs heat treatment of garbage used as pig

food

53

10302017

14

Life cycle Habitat

1 Subcutaneous tissues of man free

migrating in chest back scalp axilla

groin and may be seen under the

conjunctiva

(hence the common name eye worm)

Life cycle of Loa loa

10302017

15

2 Intermediate host (vector) Female Chrysops fly (Deer fly) day biting insect (transmission as in W Bancrofi )

3 Reservoir host Monkeys 4 The infective stage is the filariform

larvae in the mouth of chrysops

5 The Microfilaria has the following characters

250 x 5

The sheath is tight

body curves are kinky

The tail is S-shaped and full of nuclei

The periodicity is diurnal with

maximum at noon

10302017

16

Microfilaria of Loa loa

Pathogenesis amp Symptomatology

Disease Loiasis Loaiasis

Wandering of adult worms may be observed in loose

connective tissues such as eye lids conjunctiva breast

amp scrotum creeping sensation irritation and

itching congestion and oedema of eye lids

It can be seen moving under the conjunctiva or

crossing the bridge of the nose but it doesnrsquot cause

blindness

10302017

17

Loiasis of the eye

2 Calabar swellings allergic reaction to worm

metabolites It is named after a town in Eastern

Nigeria

It is a transient swelling appears suddenly and

disappears gradually within 2-3 days without

suppuration

The commonest sites are forearm hands wrist

elbows and ankle It is due to hypersensitivity

(allergic reaction) to the adult worms

microfilariae and their toxic metabolites

10302017

18

3 Complications are due to invasion of the worms to

ectopic foci causing encephalopathy due to

involvement of CNS where microfilariae can be

detected in cerebrospinal fluid (CSF)

4 Arthritis Acute arthritis with joint effusion may occur

5 Also hydrocele glomerulonephritis endomyocardial

fibrosis and retinopathy can occur

Diagnosis

1 Clinical By observing the adult worm crossing

the bridge of the nose or under the conjunctiva

together with history of calabar swelling

2 Laboratory Blood examination a drop of the

peripheral blood is taken during the day time

(10 am to 2 pm) and is examined fresh for

motile microfilariae and stained thick smear

for fixed microfilariae

10302017

19

3 History of calabar swelling

4 Serological and intradermal test

5 Eosinophiliaamp leucocytosis

Control

Treatment of infected persons

Protection by screening or by fly repellents when

visiting forests in endemic area

Chrysops control is difficult because it breeds in

swampy areas of forest

10302017

20

Laboratory Diagnosis of filaria

Identification of microfilariae by microscopic examination is the most

practical diagnostic procedure

Examination of blood samples will allow identification of microfilariae

of Wuchereria bancrofti Brugia malayi Loa loa Mansonella perstans and M

ozzardi

It is important to time the blood collection with the known

periodicity of the microfilariae

The blood sample can be a thick smear stained with Giemsa or

hematoxylin and eosin For increased sensitivity concentration

techniques can be used

These include centrifugation of the blood sample lyzed in 2 formalin

(Knotts technique) or filtration through a Nucleopore membrane

39

Examination of skin snips will identify microfilariae

of Onchocerca volvulus and Mansonella streptocerca Skin

snips can be obtained using a corneal-scleral punch or

more simply a scalpel and needle The sample must be

allowed to incubate for 30 minutes to 2 hours in saline or

culture medium

Antigen detection using an immunoassay for

circulating filarial antigens constitutes a useful

diagnostic approach because microfilaremia can be

low and variable A rapid-format

immunochromatographic test

40

10302017

21

Molecular diagnosis using PCR is available for W bancrofti

and B malayi

1048707 Identification of adult worms is possible from tissue samples collected during nodulectomies (onchocerciasis) or

during subcutaneous biopsies or worm removal from the eye

(loiasis)

1048707 Antibody detection is of limited value Substantial antigenic cross reactivity exists between filaria and other

helminths and a positive serologic test does not distinguish

between past and current infection

41

42

a Infection with

Wuchereria bancrofti

elephantiasis

b infection with Loa

loa eyelid swelling

c onchocercosis

cutaneous nodules

caused by Onchocerca

volvulus

d blindness caused by

O volvulus

e Trichinella spiralis

larvae in rat

musculature

f larva migrans

externa

10302017

22

Trichina worm Trichinella spiralis

43

و ونحى انخزير )قال تعانى بسى هللا انرح انرحيى يتة وانذ و عهيكى ان ا حر إ

حيى غفور ر هللا اضطر غير باغ ول عاد فإ به ف (ويا أهم نغير هللا

115اآليــة -انحم

Biological characteristics

Zoonosis

Ovoviviparous

Adult amp larva live in the same host individual

Adult small intestine

Larva striated muscle

44

10302017

23

Trichinella spiralis larvae in

muscle section 45 A higher power magnification

Larva of Trichinella spiralis

46

10302017

24

47

Life Cycle of T spiralis

Trichinellosis is acquired by ingesting meat containing cysts

(encysted larvae) of Trichinella

After exposure to gastric acid and pepsin the larvae are

released from the cysts and invade the small bowel mucosa

where they develop into adult worms

(female 22 mm in length males 12 mm life span in the

small bowel 4 weeks)

After 1 week the females release larvae that migrate to the

striated muscles where they encyst

Encystment is completed in 4 to 5 weeks and the encysted

larvae may remain viable for several years 48

10302017

25

Ingestion of the encysted larvae perpetuates the

cycle

Rats and rodents are primarily responsible for

maintaining the endemicity of this infection

Carnivorousomnivorous animals such as pigs or

bears feed on infected rodents or meat from other

animals

Humans are accidentally infected when eating

improperly processed meat of these carnivorous

animals (or eating food contaminated with such

meat)

49

Main Points of Life Cycle

Infective stage capsulated larva

Infection route eating raw or improperly cooked pork

or its products

No extra-hostal developing but must change host to

finish the life cycle exists many reservoir host

Human acts as IH and DH

50

10302017

26

Pathogenesis

Main pathogenic factor larva

Invasion stage (intestinal phase) minor digestive

disturbance

Migration stage (muscular phase) diarrhea myalgias

abdominal pain vomiting weakness blood eosinophilia

circumorbital edema myositis Muscular tenderness

Encystment stage recovery

51

Epidemiologiy

Cosmopolitan esp in Europe and North-America

China due to raw pork consumption

52

Diagnosis

Based on the basis of clinical symptoms and history and

eosinophilia

Etiological diagnosis

Biopsy of skeletal muscle

Immunological diagnosis (antibody detection)

10302017

27

Control methods

Hygienic education

Properly cooking pork

Low temperature storage of pork

(all larvae are killed at -15ordmC for 24hs)

Scientific raising pigs heat treatment of garbage used as pig

food

53

10302017

15

2 Intermediate host (vector) Female Chrysops fly (Deer fly) day biting insect (transmission as in W Bancrofi )

3 Reservoir host Monkeys 4 The infective stage is the filariform

larvae in the mouth of chrysops

5 The Microfilaria has the following characters

250 x 5

The sheath is tight

body curves are kinky

The tail is S-shaped and full of nuclei

The periodicity is diurnal with

maximum at noon

10302017

16

Microfilaria of Loa loa

Pathogenesis amp Symptomatology

Disease Loiasis Loaiasis

Wandering of adult worms may be observed in loose

connective tissues such as eye lids conjunctiva breast

amp scrotum creeping sensation irritation and

itching congestion and oedema of eye lids

It can be seen moving under the conjunctiva or

crossing the bridge of the nose but it doesnrsquot cause

blindness

10302017

17

Loiasis of the eye

2 Calabar swellings allergic reaction to worm

metabolites It is named after a town in Eastern

Nigeria

It is a transient swelling appears suddenly and

disappears gradually within 2-3 days without

suppuration

The commonest sites are forearm hands wrist

elbows and ankle It is due to hypersensitivity

(allergic reaction) to the adult worms

microfilariae and their toxic metabolites

10302017

18

3 Complications are due to invasion of the worms to

ectopic foci causing encephalopathy due to

involvement of CNS where microfilariae can be

detected in cerebrospinal fluid (CSF)

4 Arthritis Acute arthritis with joint effusion may occur

5 Also hydrocele glomerulonephritis endomyocardial

fibrosis and retinopathy can occur

Diagnosis

1 Clinical By observing the adult worm crossing

the bridge of the nose or under the conjunctiva

together with history of calabar swelling

2 Laboratory Blood examination a drop of the

peripheral blood is taken during the day time

(10 am to 2 pm) and is examined fresh for

motile microfilariae and stained thick smear

for fixed microfilariae

10302017

19

3 History of calabar swelling

4 Serological and intradermal test

5 Eosinophiliaamp leucocytosis

Control

Treatment of infected persons

Protection by screening or by fly repellents when

visiting forests in endemic area

Chrysops control is difficult because it breeds in

swampy areas of forest

10302017

20

Laboratory Diagnosis of filaria

Identification of microfilariae by microscopic examination is the most

practical diagnostic procedure

Examination of blood samples will allow identification of microfilariae

of Wuchereria bancrofti Brugia malayi Loa loa Mansonella perstans and M

ozzardi

It is important to time the blood collection with the known

periodicity of the microfilariae

The blood sample can be a thick smear stained with Giemsa or

hematoxylin and eosin For increased sensitivity concentration

techniques can be used

These include centrifugation of the blood sample lyzed in 2 formalin

(Knotts technique) or filtration through a Nucleopore membrane

39

Examination of skin snips will identify microfilariae

of Onchocerca volvulus and Mansonella streptocerca Skin

snips can be obtained using a corneal-scleral punch or

more simply a scalpel and needle The sample must be

allowed to incubate for 30 minutes to 2 hours in saline or

culture medium

Antigen detection using an immunoassay for

circulating filarial antigens constitutes a useful

diagnostic approach because microfilaremia can be

low and variable A rapid-format

immunochromatographic test

40

10302017

21

Molecular diagnosis using PCR is available for W bancrofti

and B malayi

1048707 Identification of adult worms is possible from tissue samples collected during nodulectomies (onchocerciasis) or

during subcutaneous biopsies or worm removal from the eye

(loiasis)

1048707 Antibody detection is of limited value Substantial antigenic cross reactivity exists between filaria and other

helminths and a positive serologic test does not distinguish

between past and current infection

41

42

a Infection with

Wuchereria bancrofti

elephantiasis

b infection with Loa

loa eyelid swelling

c onchocercosis

cutaneous nodules

caused by Onchocerca

volvulus

d blindness caused by

O volvulus

e Trichinella spiralis

larvae in rat

musculature

f larva migrans

externa

10302017

22

Trichina worm Trichinella spiralis

43

و ونحى انخزير )قال تعانى بسى هللا انرح انرحيى يتة وانذ و عهيكى ان ا حر إ

حيى غفور ر هللا اضطر غير باغ ول عاد فإ به ف (ويا أهم نغير هللا

115اآليــة -انحم

Biological characteristics

Zoonosis

Ovoviviparous

Adult amp larva live in the same host individual

Adult small intestine

Larva striated muscle

44

10302017

23

Trichinella spiralis larvae in

muscle section 45 A higher power magnification

Larva of Trichinella spiralis

46

10302017

24

47

Life Cycle of T spiralis

Trichinellosis is acquired by ingesting meat containing cysts

(encysted larvae) of Trichinella

After exposure to gastric acid and pepsin the larvae are

released from the cysts and invade the small bowel mucosa

where they develop into adult worms

(female 22 mm in length males 12 mm life span in the

small bowel 4 weeks)

After 1 week the females release larvae that migrate to the

striated muscles where they encyst

Encystment is completed in 4 to 5 weeks and the encysted

larvae may remain viable for several years 48

10302017

25

Ingestion of the encysted larvae perpetuates the

cycle

Rats and rodents are primarily responsible for

maintaining the endemicity of this infection

Carnivorousomnivorous animals such as pigs or

bears feed on infected rodents or meat from other

animals

Humans are accidentally infected when eating

improperly processed meat of these carnivorous

animals (or eating food contaminated with such

meat)

49

Main Points of Life Cycle

Infective stage capsulated larva

Infection route eating raw or improperly cooked pork

or its products

No extra-hostal developing but must change host to

finish the life cycle exists many reservoir host

Human acts as IH and DH

50

10302017

26

Pathogenesis

Main pathogenic factor larva

Invasion stage (intestinal phase) minor digestive

disturbance

Migration stage (muscular phase) diarrhea myalgias

abdominal pain vomiting weakness blood eosinophilia

circumorbital edema myositis Muscular tenderness

Encystment stage recovery

51

Epidemiologiy

Cosmopolitan esp in Europe and North-America

China due to raw pork consumption

52

Diagnosis

Based on the basis of clinical symptoms and history and

eosinophilia

Etiological diagnosis

Biopsy of skeletal muscle

Immunological diagnosis (antibody detection)

10302017

27

Control methods

Hygienic education

Properly cooking pork

Low temperature storage of pork

(all larvae are killed at -15ordmC for 24hs)

Scientific raising pigs heat treatment of garbage used as pig

food

53

10302017

16

Microfilaria of Loa loa

Pathogenesis amp Symptomatology

Disease Loiasis Loaiasis

Wandering of adult worms may be observed in loose

connective tissues such as eye lids conjunctiva breast

amp scrotum creeping sensation irritation and

itching congestion and oedema of eye lids

It can be seen moving under the conjunctiva or

crossing the bridge of the nose but it doesnrsquot cause

blindness

10302017

17

Loiasis of the eye

2 Calabar swellings allergic reaction to worm

metabolites It is named after a town in Eastern

Nigeria

It is a transient swelling appears suddenly and

disappears gradually within 2-3 days without

suppuration

The commonest sites are forearm hands wrist

elbows and ankle It is due to hypersensitivity

(allergic reaction) to the adult worms

microfilariae and their toxic metabolites

10302017

18

3 Complications are due to invasion of the worms to

ectopic foci causing encephalopathy due to

involvement of CNS where microfilariae can be

detected in cerebrospinal fluid (CSF)

4 Arthritis Acute arthritis with joint effusion may occur

5 Also hydrocele glomerulonephritis endomyocardial

fibrosis and retinopathy can occur

Diagnosis

1 Clinical By observing the adult worm crossing

the bridge of the nose or under the conjunctiva

together with history of calabar swelling

2 Laboratory Blood examination a drop of the

peripheral blood is taken during the day time

(10 am to 2 pm) and is examined fresh for

motile microfilariae and stained thick smear

for fixed microfilariae

10302017

19

3 History of calabar swelling

4 Serological and intradermal test

5 Eosinophiliaamp leucocytosis

Control

Treatment of infected persons

Protection by screening or by fly repellents when

visiting forests in endemic area

Chrysops control is difficult because it breeds in

swampy areas of forest

10302017

20

Laboratory Diagnosis of filaria

Identification of microfilariae by microscopic examination is the most

practical diagnostic procedure

Examination of blood samples will allow identification of microfilariae

of Wuchereria bancrofti Brugia malayi Loa loa Mansonella perstans and M

ozzardi

It is important to time the blood collection with the known

periodicity of the microfilariae

The blood sample can be a thick smear stained with Giemsa or

hematoxylin and eosin For increased sensitivity concentration

techniques can be used

These include centrifugation of the blood sample lyzed in 2 formalin

(Knotts technique) or filtration through a Nucleopore membrane

39

Examination of skin snips will identify microfilariae

of Onchocerca volvulus and Mansonella streptocerca Skin

snips can be obtained using a corneal-scleral punch or

more simply a scalpel and needle The sample must be

allowed to incubate for 30 minutes to 2 hours in saline or

culture medium

Antigen detection using an immunoassay for

circulating filarial antigens constitutes a useful

diagnostic approach because microfilaremia can be

low and variable A rapid-format

immunochromatographic test

40

10302017

21

Molecular diagnosis using PCR is available for W bancrofti

and B malayi

1048707 Identification of adult worms is possible from tissue samples collected during nodulectomies (onchocerciasis) or

during subcutaneous biopsies or worm removal from the eye

(loiasis)

1048707 Antibody detection is of limited value Substantial antigenic cross reactivity exists between filaria and other

helminths and a positive serologic test does not distinguish

between past and current infection

41

42

a Infection with

Wuchereria bancrofti

elephantiasis

b infection with Loa

loa eyelid swelling

c onchocercosis

cutaneous nodules

caused by Onchocerca

volvulus

d blindness caused by

O volvulus

e Trichinella spiralis

larvae in rat

musculature

f larva migrans

externa

10302017

22

Trichina worm Trichinella spiralis

43

و ونحى انخزير )قال تعانى بسى هللا انرح انرحيى يتة وانذ و عهيكى ان ا حر إ

حيى غفور ر هللا اضطر غير باغ ول عاد فإ به ف (ويا أهم نغير هللا

115اآليــة -انحم

Biological characteristics

Zoonosis

Ovoviviparous

Adult amp larva live in the same host individual

Adult small intestine

Larva striated muscle

44

10302017

23

Trichinella spiralis larvae in

muscle section 45 A higher power magnification

Larva of Trichinella spiralis

46

10302017

24

47

Life Cycle of T spiralis

Trichinellosis is acquired by ingesting meat containing cysts

(encysted larvae) of Trichinella

After exposure to gastric acid and pepsin the larvae are

released from the cysts and invade the small bowel mucosa

where they develop into adult worms

(female 22 mm in length males 12 mm life span in the

small bowel 4 weeks)

After 1 week the females release larvae that migrate to the

striated muscles where they encyst

Encystment is completed in 4 to 5 weeks and the encysted

larvae may remain viable for several years 48

10302017

25

Ingestion of the encysted larvae perpetuates the

cycle

Rats and rodents are primarily responsible for

maintaining the endemicity of this infection

Carnivorousomnivorous animals such as pigs or

bears feed on infected rodents or meat from other

animals

Humans are accidentally infected when eating

improperly processed meat of these carnivorous

animals (or eating food contaminated with such

meat)

49

Main Points of Life Cycle

Infective stage capsulated larva

Infection route eating raw or improperly cooked pork

or its products

No extra-hostal developing but must change host to

finish the life cycle exists many reservoir host

Human acts as IH and DH

50

10302017

26

Pathogenesis

Main pathogenic factor larva

Invasion stage (intestinal phase) minor digestive

disturbance

Migration stage (muscular phase) diarrhea myalgias

abdominal pain vomiting weakness blood eosinophilia

circumorbital edema myositis Muscular tenderness

Encystment stage recovery

51

Epidemiologiy

Cosmopolitan esp in Europe and North-America

China due to raw pork consumption

52

Diagnosis

Based on the basis of clinical symptoms and history and

eosinophilia

Etiological diagnosis

Biopsy of skeletal muscle

Immunological diagnosis (antibody detection)

10302017

27

Control methods

Hygienic education

Properly cooking pork

Low temperature storage of pork

(all larvae are killed at -15ordmC for 24hs)

Scientific raising pigs heat treatment of garbage used as pig

food

53

10302017

17

Loiasis of the eye

2 Calabar swellings allergic reaction to worm

metabolites It is named after a town in Eastern

Nigeria

It is a transient swelling appears suddenly and

disappears gradually within 2-3 days without

suppuration

The commonest sites are forearm hands wrist

elbows and ankle It is due to hypersensitivity

(allergic reaction) to the adult worms

microfilariae and their toxic metabolites

10302017

18

3 Complications are due to invasion of the worms to

ectopic foci causing encephalopathy due to

involvement of CNS where microfilariae can be

detected in cerebrospinal fluid (CSF)

4 Arthritis Acute arthritis with joint effusion may occur

5 Also hydrocele glomerulonephritis endomyocardial

fibrosis and retinopathy can occur

Diagnosis

1 Clinical By observing the adult worm crossing

the bridge of the nose or under the conjunctiva

together with history of calabar swelling

2 Laboratory Blood examination a drop of the

peripheral blood is taken during the day time

(10 am to 2 pm) and is examined fresh for

motile microfilariae and stained thick smear

for fixed microfilariae

10302017

19

3 History of calabar swelling

4 Serological and intradermal test

5 Eosinophiliaamp leucocytosis

Control

Treatment of infected persons

Protection by screening or by fly repellents when

visiting forests in endemic area

Chrysops control is difficult because it breeds in

swampy areas of forest

10302017

20

Laboratory Diagnosis of filaria

Identification of microfilariae by microscopic examination is the most

practical diagnostic procedure

Examination of blood samples will allow identification of microfilariae

of Wuchereria bancrofti Brugia malayi Loa loa Mansonella perstans and M

ozzardi

It is important to time the blood collection with the known

periodicity of the microfilariae

The blood sample can be a thick smear stained with Giemsa or

hematoxylin and eosin For increased sensitivity concentration

techniques can be used

These include centrifugation of the blood sample lyzed in 2 formalin

(Knotts technique) or filtration through a Nucleopore membrane

39

Examination of skin snips will identify microfilariae

of Onchocerca volvulus and Mansonella streptocerca Skin

snips can be obtained using a corneal-scleral punch or

more simply a scalpel and needle The sample must be

allowed to incubate for 30 minutes to 2 hours in saline or

culture medium

Antigen detection using an immunoassay for

circulating filarial antigens constitutes a useful

diagnostic approach because microfilaremia can be

low and variable A rapid-format

immunochromatographic test

40

10302017

21

Molecular diagnosis using PCR is available for W bancrofti

and B malayi

1048707 Identification of adult worms is possible from tissue samples collected during nodulectomies (onchocerciasis) or

during subcutaneous biopsies or worm removal from the eye

(loiasis)

1048707 Antibody detection is of limited value Substantial antigenic cross reactivity exists between filaria and other

helminths and a positive serologic test does not distinguish

between past and current infection

41

42

a Infection with

Wuchereria bancrofti

elephantiasis

b infection with Loa

loa eyelid swelling

c onchocercosis

cutaneous nodules

caused by Onchocerca

volvulus

d blindness caused by

O volvulus

e Trichinella spiralis

larvae in rat

musculature

f larva migrans

externa

10302017

22

Trichina worm Trichinella spiralis

43

و ونحى انخزير )قال تعانى بسى هللا انرح انرحيى يتة وانذ و عهيكى ان ا حر إ

حيى غفور ر هللا اضطر غير باغ ول عاد فإ به ف (ويا أهم نغير هللا

115اآليــة -انحم

Biological characteristics

Zoonosis

Ovoviviparous

Adult amp larva live in the same host individual

Adult small intestine

Larva striated muscle

44

10302017

23

Trichinella spiralis larvae in

muscle section 45 A higher power magnification

Larva of Trichinella spiralis

46

10302017

24

47

Life Cycle of T spiralis

Trichinellosis is acquired by ingesting meat containing cysts

(encysted larvae) of Trichinella

After exposure to gastric acid and pepsin the larvae are

released from the cysts and invade the small bowel mucosa

where they develop into adult worms

(female 22 mm in length males 12 mm life span in the

small bowel 4 weeks)

After 1 week the females release larvae that migrate to the

striated muscles where they encyst

Encystment is completed in 4 to 5 weeks and the encysted

larvae may remain viable for several years 48

10302017

25

Ingestion of the encysted larvae perpetuates the

cycle

Rats and rodents are primarily responsible for

maintaining the endemicity of this infection

Carnivorousomnivorous animals such as pigs or

bears feed on infected rodents or meat from other

animals

Humans are accidentally infected when eating

improperly processed meat of these carnivorous

animals (or eating food contaminated with such

meat)

49

Main Points of Life Cycle

Infective stage capsulated larva

Infection route eating raw or improperly cooked pork

or its products

No extra-hostal developing but must change host to

finish the life cycle exists many reservoir host

Human acts as IH and DH

50

10302017

26

Pathogenesis

Main pathogenic factor larva

Invasion stage (intestinal phase) minor digestive

disturbance

Migration stage (muscular phase) diarrhea myalgias

abdominal pain vomiting weakness blood eosinophilia

circumorbital edema myositis Muscular tenderness

Encystment stage recovery

51

Epidemiologiy

Cosmopolitan esp in Europe and North-America

China due to raw pork consumption

52

Diagnosis

Based on the basis of clinical symptoms and history and

eosinophilia

Etiological diagnosis

Biopsy of skeletal muscle

Immunological diagnosis (antibody detection)

10302017

27

Control methods

Hygienic education

Properly cooking pork

Low temperature storage of pork

(all larvae are killed at -15ordmC for 24hs)

Scientific raising pigs heat treatment of garbage used as pig

food

53

10302017

18

3 Complications are due to invasion of the worms to

ectopic foci causing encephalopathy due to

involvement of CNS where microfilariae can be

detected in cerebrospinal fluid (CSF)

4 Arthritis Acute arthritis with joint effusion may occur

5 Also hydrocele glomerulonephritis endomyocardial

fibrosis and retinopathy can occur

Diagnosis

1 Clinical By observing the adult worm crossing

the bridge of the nose or under the conjunctiva

together with history of calabar swelling

2 Laboratory Blood examination a drop of the

peripheral blood is taken during the day time

(10 am to 2 pm) and is examined fresh for

motile microfilariae and stained thick smear

for fixed microfilariae

10302017

19

3 History of calabar swelling

4 Serological and intradermal test

5 Eosinophiliaamp leucocytosis

Control

Treatment of infected persons

Protection by screening or by fly repellents when

visiting forests in endemic area

Chrysops control is difficult because it breeds in

swampy areas of forest

10302017

20

Laboratory Diagnosis of filaria

Identification of microfilariae by microscopic examination is the most

practical diagnostic procedure

Examination of blood samples will allow identification of microfilariae

of Wuchereria bancrofti Brugia malayi Loa loa Mansonella perstans and M

ozzardi

It is important to time the blood collection with the known

periodicity of the microfilariae

The blood sample can be a thick smear stained with Giemsa or

hematoxylin and eosin For increased sensitivity concentration

techniques can be used

These include centrifugation of the blood sample lyzed in 2 formalin

(Knotts technique) or filtration through a Nucleopore membrane

39

Examination of skin snips will identify microfilariae

of Onchocerca volvulus and Mansonella streptocerca Skin

snips can be obtained using a corneal-scleral punch or

more simply a scalpel and needle The sample must be

allowed to incubate for 30 minutes to 2 hours in saline or

culture medium

Antigen detection using an immunoassay for

circulating filarial antigens constitutes a useful

diagnostic approach because microfilaremia can be

low and variable A rapid-format

immunochromatographic test

40

10302017

21

Molecular diagnosis using PCR is available for W bancrofti

and B malayi

1048707 Identification of adult worms is possible from tissue samples collected during nodulectomies (onchocerciasis) or

during subcutaneous biopsies or worm removal from the eye

(loiasis)

1048707 Antibody detection is of limited value Substantial antigenic cross reactivity exists between filaria and other

helminths and a positive serologic test does not distinguish

between past and current infection

41

42

a Infection with

Wuchereria bancrofti

elephantiasis

b infection with Loa

loa eyelid swelling

c onchocercosis

cutaneous nodules

caused by Onchocerca

volvulus

d blindness caused by

O volvulus

e Trichinella spiralis

larvae in rat

musculature

f larva migrans

externa

10302017

22

Trichina worm Trichinella spiralis

43

و ونحى انخزير )قال تعانى بسى هللا انرح انرحيى يتة وانذ و عهيكى ان ا حر إ

حيى غفور ر هللا اضطر غير باغ ول عاد فإ به ف (ويا أهم نغير هللا

115اآليــة -انحم

Biological characteristics

Zoonosis

Ovoviviparous

Adult amp larva live in the same host individual

Adult small intestine

Larva striated muscle

44

10302017

23

Trichinella spiralis larvae in

muscle section 45 A higher power magnification

Larva of Trichinella spiralis

46

10302017

24

47

Life Cycle of T spiralis

Trichinellosis is acquired by ingesting meat containing cysts

(encysted larvae) of Trichinella

After exposure to gastric acid and pepsin the larvae are

released from the cysts and invade the small bowel mucosa

where they develop into adult worms

(female 22 mm in length males 12 mm life span in the

small bowel 4 weeks)

After 1 week the females release larvae that migrate to the

striated muscles where they encyst

Encystment is completed in 4 to 5 weeks and the encysted

larvae may remain viable for several years 48

10302017

25

Ingestion of the encysted larvae perpetuates the

cycle

Rats and rodents are primarily responsible for

maintaining the endemicity of this infection

Carnivorousomnivorous animals such as pigs or

bears feed on infected rodents or meat from other

animals

Humans are accidentally infected when eating

improperly processed meat of these carnivorous

animals (or eating food contaminated with such

meat)

49

Main Points of Life Cycle

Infective stage capsulated larva

Infection route eating raw or improperly cooked pork

or its products

No extra-hostal developing but must change host to

finish the life cycle exists many reservoir host

Human acts as IH and DH

50

10302017

26

Pathogenesis

Main pathogenic factor larva

Invasion stage (intestinal phase) minor digestive

disturbance

Migration stage (muscular phase) diarrhea myalgias

abdominal pain vomiting weakness blood eosinophilia

circumorbital edema myositis Muscular tenderness

Encystment stage recovery

51

Epidemiologiy

Cosmopolitan esp in Europe and North-America

China due to raw pork consumption

52

Diagnosis

Based on the basis of clinical symptoms and history and

eosinophilia

Etiological diagnosis

Biopsy of skeletal muscle

Immunological diagnosis (antibody detection)

10302017

27

Control methods

Hygienic education

Properly cooking pork

Low temperature storage of pork

(all larvae are killed at -15ordmC for 24hs)

Scientific raising pigs heat treatment of garbage used as pig

food

53

10302017

19

3 History of calabar swelling

4 Serological and intradermal test

5 Eosinophiliaamp leucocytosis

Control

Treatment of infected persons

Protection by screening or by fly repellents when

visiting forests in endemic area

Chrysops control is difficult because it breeds in

swampy areas of forest

10302017

20

Laboratory Diagnosis of filaria

Identification of microfilariae by microscopic examination is the most

practical diagnostic procedure

Examination of blood samples will allow identification of microfilariae

of Wuchereria bancrofti Brugia malayi Loa loa Mansonella perstans and M

ozzardi

It is important to time the blood collection with the known

periodicity of the microfilariae

The blood sample can be a thick smear stained with Giemsa or

hematoxylin and eosin For increased sensitivity concentration

techniques can be used

These include centrifugation of the blood sample lyzed in 2 formalin

(Knotts technique) or filtration through a Nucleopore membrane

39

Examination of skin snips will identify microfilariae

of Onchocerca volvulus and Mansonella streptocerca Skin

snips can be obtained using a corneal-scleral punch or

more simply a scalpel and needle The sample must be

allowed to incubate for 30 minutes to 2 hours in saline or

culture medium

Antigen detection using an immunoassay for

circulating filarial antigens constitutes a useful

diagnostic approach because microfilaremia can be

low and variable A rapid-format

immunochromatographic test

40

10302017

21

Molecular diagnosis using PCR is available for W bancrofti

and B malayi

1048707 Identification of adult worms is possible from tissue samples collected during nodulectomies (onchocerciasis) or

during subcutaneous biopsies or worm removal from the eye

(loiasis)

1048707 Antibody detection is of limited value Substantial antigenic cross reactivity exists between filaria and other

helminths and a positive serologic test does not distinguish

between past and current infection

41

42

a Infection with

Wuchereria bancrofti

elephantiasis

b infection with Loa

loa eyelid swelling

c onchocercosis

cutaneous nodules

caused by Onchocerca

volvulus

d blindness caused by

O volvulus

e Trichinella spiralis

larvae in rat

musculature

f larva migrans

externa

10302017

22

Trichina worm Trichinella spiralis

43

و ونحى انخزير )قال تعانى بسى هللا انرح انرحيى يتة وانذ و عهيكى ان ا حر إ

حيى غفور ر هللا اضطر غير باغ ول عاد فإ به ف (ويا أهم نغير هللا

115اآليــة -انحم

Biological characteristics

Zoonosis

Ovoviviparous

Adult amp larva live in the same host individual

Adult small intestine

Larva striated muscle

44

10302017

23

Trichinella spiralis larvae in

muscle section 45 A higher power magnification

Larva of Trichinella spiralis

46

10302017

24

47

Life Cycle of T spiralis

Trichinellosis is acquired by ingesting meat containing cysts

(encysted larvae) of Trichinella

After exposure to gastric acid and pepsin the larvae are

released from the cysts and invade the small bowel mucosa

where they develop into adult worms

(female 22 mm in length males 12 mm life span in the

small bowel 4 weeks)

After 1 week the females release larvae that migrate to the

striated muscles where they encyst

Encystment is completed in 4 to 5 weeks and the encysted

larvae may remain viable for several years 48

10302017

25

Ingestion of the encysted larvae perpetuates the

cycle

Rats and rodents are primarily responsible for

maintaining the endemicity of this infection

Carnivorousomnivorous animals such as pigs or

bears feed on infected rodents or meat from other

animals

Humans are accidentally infected when eating

improperly processed meat of these carnivorous

animals (or eating food contaminated with such

meat)

49

Main Points of Life Cycle

Infective stage capsulated larva

Infection route eating raw or improperly cooked pork

or its products

No extra-hostal developing but must change host to

finish the life cycle exists many reservoir host

Human acts as IH and DH

50

10302017

26

Pathogenesis

Main pathogenic factor larva

Invasion stage (intestinal phase) minor digestive

disturbance

Migration stage (muscular phase) diarrhea myalgias

abdominal pain vomiting weakness blood eosinophilia

circumorbital edema myositis Muscular tenderness

Encystment stage recovery

51

Epidemiologiy

Cosmopolitan esp in Europe and North-America

China due to raw pork consumption

52

Diagnosis

Based on the basis of clinical symptoms and history and

eosinophilia

Etiological diagnosis

Biopsy of skeletal muscle

Immunological diagnosis (antibody detection)

10302017

27

Control methods

Hygienic education

Properly cooking pork

Low temperature storage of pork

(all larvae are killed at -15ordmC for 24hs)

Scientific raising pigs heat treatment of garbage used as pig

food

53

10302017

20

Laboratory Diagnosis of filaria

Identification of microfilariae by microscopic examination is the most

practical diagnostic procedure

Examination of blood samples will allow identification of microfilariae

of Wuchereria bancrofti Brugia malayi Loa loa Mansonella perstans and M

ozzardi

It is important to time the blood collection with the known

periodicity of the microfilariae

The blood sample can be a thick smear stained with Giemsa or

hematoxylin and eosin For increased sensitivity concentration

techniques can be used

These include centrifugation of the blood sample lyzed in 2 formalin

(Knotts technique) or filtration through a Nucleopore membrane

39

Examination of skin snips will identify microfilariae

of Onchocerca volvulus and Mansonella streptocerca Skin

snips can be obtained using a corneal-scleral punch or

more simply a scalpel and needle The sample must be

allowed to incubate for 30 minutes to 2 hours in saline or

culture medium

Antigen detection using an immunoassay for

circulating filarial antigens constitutes a useful

diagnostic approach because microfilaremia can be

low and variable A rapid-format

immunochromatographic test

40

10302017

21

Molecular diagnosis using PCR is available for W bancrofti

and B malayi

1048707 Identification of adult worms is possible from tissue samples collected during nodulectomies (onchocerciasis) or

during subcutaneous biopsies or worm removal from the eye

(loiasis)

1048707 Antibody detection is of limited value Substantial antigenic cross reactivity exists between filaria and other

helminths and a positive serologic test does not distinguish

between past and current infection

41

42

a Infection with

Wuchereria bancrofti

elephantiasis

b infection with Loa

loa eyelid swelling

c onchocercosis

cutaneous nodules

caused by Onchocerca

volvulus

d blindness caused by

O volvulus

e Trichinella spiralis

larvae in rat

musculature

f larva migrans

externa

10302017

22

Trichina worm Trichinella spiralis

43

و ونحى انخزير )قال تعانى بسى هللا انرح انرحيى يتة وانذ و عهيكى ان ا حر إ

حيى غفور ر هللا اضطر غير باغ ول عاد فإ به ف (ويا أهم نغير هللا

115اآليــة -انحم

Biological characteristics

Zoonosis

Ovoviviparous

Adult amp larva live in the same host individual

Adult small intestine

Larva striated muscle

44

10302017

23

Trichinella spiralis larvae in

muscle section 45 A higher power magnification

Larva of Trichinella spiralis

46

10302017

24

47

Life Cycle of T spiralis

Trichinellosis is acquired by ingesting meat containing cysts

(encysted larvae) of Trichinella

After exposure to gastric acid and pepsin the larvae are

released from the cysts and invade the small bowel mucosa

where they develop into adult worms

(female 22 mm in length males 12 mm life span in the

small bowel 4 weeks)

After 1 week the females release larvae that migrate to the

striated muscles where they encyst

Encystment is completed in 4 to 5 weeks and the encysted

larvae may remain viable for several years 48

10302017

25

Ingestion of the encysted larvae perpetuates the

cycle

Rats and rodents are primarily responsible for

maintaining the endemicity of this infection

Carnivorousomnivorous animals such as pigs or

bears feed on infected rodents or meat from other

animals

Humans are accidentally infected when eating

improperly processed meat of these carnivorous

animals (or eating food contaminated with such

meat)

49

Main Points of Life Cycle

Infective stage capsulated larva

Infection route eating raw or improperly cooked pork

or its products

No extra-hostal developing but must change host to

finish the life cycle exists many reservoir host

Human acts as IH and DH

50

10302017

26

Pathogenesis

Main pathogenic factor larva

Invasion stage (intestinal phase) minor digestive

disturbance

Migration stage (muscular phase) diarrhea myalgias

abdominal pain vomiting weakness blood eosinophilia

circumorbital edema myositis Muscular tenderness

Encystment stage recovery

51

Epidemiologiy

Cosmopolitan esp in Europe and North-America

China due to raw pork consumption

52

Diagnosis

Based on the basis of clinical symptoms and history and

eosinophilia

Etiological diagnosis

Biopsy of skeletal muscle

Immunological diagnosis (antibody detection)

10302017

27

Control methods

Hygienic education

Properly cooking pork

Low temperature storage of pork

(all larvae are killed at -15ordmC for 24hs)

Scientific raising pigs heat treatment of garbage used as pig

food

53

10302017

21

Molecular diagnosis using PCR is available for W bancrofti

and B malayi

1048707 Identification of adult worms is possible from tissue samples collected during nodulectomies (onchocerciasis) or

during subcutaneous biopsies or worm removal from the eye

(loiasis)

1048707 Antibody detection is of limited value Substantial antigenic cross reactivity exists between filaria and other

helminths and a positive serologic test does not distinguish

between past and current infection

41

42

a Infection with

Wuchereria bancrofti

elephantiasis

b infection with Loa

loa eyelid swelling

c onchocercosis

cutaneous nodules

caused by Onchocerca

volvulus

d blindness caused by

O volvulus

e Trichinella spiralis

larvae in rat

musculature

f larva migrans

externa

10302017

22

Trichina worm Trichinella spiralis

43

و ونحى انخزير )قال تعانى بسى هللا انرح انرحيى يتة وانذ و عهيكى ان ا حر إ

حيى غفور ر هللا اضطر غير باغ ول عاد فإ به ف (ويا أهم نغير هللا

115اآليــة -انحم

Biological characteristics

Zoonosis

Ovoviviparous

Adult amp larva live in the same host individual

Adult small intestine

Larva striated muscle

44

10302017

23

Trichinella spiralis larvae in

muscle section 45 A higher power magnification

Larva of Trichinella spiralis

46

10302017

24

47

Life Cycle of T spiralis

Trichinellosis is acquired by ingesting meat containing cysts

(encysted larvae) of Trichinella

After exposure to gastric acid and pepsin the larvae are

released from the cysts and invade the small bowel mucosa

where they develop into adult worms

(female 22 mm in length males 12 mm life span in the

small bowel 4 weeks)

After 1 week the females release larvae that migrate to the

striated muscles where they encyst

Encystment is completed in 4 to 5 weeks and the encysted

larvae may remain viable for several years 48

10302017

25

Ingestion of the encysted larvae perpetuates the

cycle

Rats and rodents are primarily responsible for

maintaining the endemicity of this infection

Carnivorousomnivorous animals such as pigs or

bears feed on infected rodents or meat from other

animals

Humans are accidentally infected when eating

improperly processed meat of these carnivorous

animals (or eating food contaminated with such

meat)

49

Main Points of Life Cycle

Infective stage capsulated larva

Infection route eating raw or improperly cooked pork

or its products

No extra-hostal developing but must change host to

finish the life cycle exists many reservoir host

Human acts as IH and DH

50

10302017

26

Pathogenesis

Main pathogenic factor larva

Invasion stage (intestinal phase) minor digestive

disturbance

Migration stage (muscular phase) diarrhea myalgias

abdominal pain vomiting weakness blood eosinophilia

circumorbital edema myositis Muscular tenderness

Encystment stage recovery

51

Epidemiologiy

Cosmopolitan esp in Europe and North-America

China due to raw pork consumption

52

Diagnosis

Based on the basis of clinical symptoms and history and

eosinophilia

Etiological diagnosis

Biopsy of skeletal muscle

Immunological diagnosis (antibody detection)

10302017

27

Control methods

Hygienic education

Properly cooking pork

Low temperature storage of pork

(all larvae are killed at -15ordmC for 24hs)

Scientific raising pigs heat treatment of garbage used as pig

food

53

10302017

22

Trichina worm Trichinella spiralis

43

و ونحى انخزير )قال تعانى بسى هللا انرح انرحيى يتة وانذ و عهيكى ان ا حر إ

حيى غفور ر هللا اضطر غير باغ ول عاد فإ به ف (ويا أهم نغير هللا

115اآليــة -انحم

Biological characteristics

Zoonosis

Ovoviviparous

Adult amp larva live in the same host individual

Adult small intestine

Larva striated muscle

44

10302017

23

Trichinella spiralis larvae in

muscle section 45 A higher power magnification

Larva of Trichinella spiralis

46

10302017

24

47

Life Cycle of T spiralis

Trichinellosis is acquired by ingesting meat containing cysts

(encysted larvae) of Trichinella

After exposure to gastric acid and pepsin the larvae are

released from the cysts and invade the small bowel mucosa

where they develop into adult worms

(female 22 mm in length males 12 mm life span in the

small bowel 4 weeks)

After 1 week the females release larvae that migrate to the

striated muscles where they encyst

Encystment is completed in 4 to 5 weeks and the encysted

larvae may remain viable for several years 48

10302017

25

Ingestion of the encysted larvae perpetuates the

cycle

Rats and rodents are primarily responsible for

maintaining the endemicity of this infection

Carnivorousomnivorous animals such as pigs or

bears feed on infected rodents or meat from other

animals

Humans are accidentally infected when eating

improperly processed meat of these carnivorous

animals (or eating food contaminated with such

meat)

49

Main Points of Life Cycle

Infective stage capsulated larva

Infection route eating raw or improperly cooked pork

or its products

No extra-hostal developing but must change host to

finish the life cycle exists many reservoir host

Human acts as IH and DH

50

10302017

26

Pathogenesis

Main pathogenic factor larva

Invasion stage (intestinal phase) minor digestive

disturbance

Migration stage (muscular phase) diarrhea myalgias

abdominal pain vomiting weakness blood eosinophilia

circumorbital edema myositis Muscular tenderness

Encystment stage recovery

51

Epidemiologiy

Cosmopolitan esp in Europe and North-America

China due to raw pork consumption

52

Diagnosis

Based on the basis of clinical symptoms and history and

eosinophilia

Etiological diagnosis

Biopsy of skeletal muscle

Immunological diagnosis (antibody detection)

10302017

27

Control methods

Hygienic education

Properly cooking pork

Low temperature storage of pork

(all larvae are killed at -15ordmC for 24hs)

Scientific raising pigs heat treatment of garbage used as pig

food

53

10302017

23

Trichinella spiralis larvae in

muscle section 45 A higher power magnification

Larva of Trichinella spiralis

46

10302017

24

47

Life Cycle of T spiralis

Trichinellosis is acquired by ingesting meat containing cysts

(encysted larvae) of Trichinella

After exposure to gastric acid and pepsin the larvae are

released from the cysts and invade the small bowel mucosa

where they develop into adult worms

(female 22 mm in length males 12 mm life span in the

small bowel 4 weeks)

After 1 week the females release larvae that migrate to the

striated muscles where they encyst

Encystment is completed in 4 to 5 weeks and the encysted

larvae may remain viable for several years 48

10302017

25

Ingestion of the encysted larvae perpetuates the

cycle

Rats and rodents are primarily responsible for

maintaining the endemicity of this infection

Carnivorousomnivorous animals such as pigs or

bears feed on infected rodents or meat from other

animals

Humans are accidentally infected when eating

improperly processed meat of these carnivorous

animals (or eating food contaminated with such

meat)

49

Main Points of Life Cycle

Infective stage capsulated larva

Infection route eating raw or improperly cooked pork

or its products

No extra-hostal developing but must change host to

finish the life cycle exists many reservoir host

Human acts as IH and DH

50

10302017

26

Pathogenesis

Main pathogenic factor larva

Invasion stage (intestinal phase) minor digestive

disturbance

Migration stage (muscular phase) diarrhea myalgias

abdominal pain vomiting weakness blood eosinophilia

circumorbital edema myositis Muscular tenderness

Encystment stage recovery

51

Epidemiologiy

Cosmopolitan esp in Europe and North-America

China due to raw pork consumption

52

Diagnosis

Based on the basis of clinical symptoms and history and

eosinophilia

Etiological diagnosis

Biopsy of skeletal muscle

Immunological diagnosis (antibody detection)

10302017

27

Control methods

Hygienic education

Properly cooking pork

Low temperature storage of pork

(all larvae are killed at -15ordmC for 24hs)

Scientific raising pigs heat treatment of garbage used as pig

food

53

10302017

24

47

Life Cycle of T spiralis

Trichinellosis is acquired by ingesting meat containing cysts

(encysted larvae) of Trichinella

After exposure to gastric acid and pepsin the larvae are

released from the cysts and invade the small bowel mucosa

where they develop into adult worms

(female 22 mm in length males 12 mm life span in the

small bowel 4 weeks)

After 1 week the females release larvae that migrate to the

striated muscles where they encyst

Encystment is completed in 4 to 5 weeks and the encysted

larvae may remain viable for several years 48

10302017

25

Ingestion of the encysted larvae perpetuates the

cycle

Rats and rodents are primarily responsible for

maintaining the endemicity of this infection

Carnivorousomnivorous animals such as pigs or

bears feed on infected rodents or meat from other

animals

Humans are accidentally infected when eating

improperly processed meat of these carnivorous

animals (or eating food contaminated with such

meat)

49

Main Points of Life Cycle

Infective stage capsulated larva

Infection route eating raw or improperly cooked pork

or its products

No extra-hostal developing but must change host to

finish the life cycle exists many reservoir host

Human acts as IH and DH

50

10302017

26

Pathogenesis

Main pathogenic factor larva

Invasion stage (intestinal phase) minor digestive

disturbance

Migration stage (muscular phase) diarrhea myalgias

abdominal pain vomiting weakness blood eosinophilia

circumorbital edema myositis Muscular tenderness

Encystment stage recovery

51

Epidemiologiy

Cosmopolitan esp in Europe and North-America

China due to raw pork consumption

52

Diagnosis

Based on the basis of clinical symptoms and history and

eosinophilia

Etiological diagnosis

Biopsy of skeletal muscle

Immunological diagnosis (antibody detection)

10302017

27

Control methods

Hygienic education

Properly cooking pork

Low temperature storage of pork

(all larvae are killed at -15ordmC for 24hs)

Scientific raising pigs heat treatment of garbage used as pig

food

53

10302017

25

Ingestion of the encysted larvae perpetuates the

cycle

Rats and rodents are primarily responsible for

maintaining the endemicity of this infection

Carnivorousomnivorous animals such as pigs or

bears feed on infected rodents or meat from other

animals

Humans are accidentally infected when eating

improperly processed meat of these carnivorous

animals (or eating food contaminated with such

meat)

49

Main Points of Life Cycle

Infective stage capsulated larva

Infection route eating raw or improperly cooked pork

or its products

No extra-hostal developing but must change host to

finish the life cycle exists many reservoir host

Human acts as IH and DH

50

10302017

26

Pathogenesis

Main pathogenic factor larva

Invasion stage (intestinal phase) minor digestive

disturbance

Migration stage (muscular phase) diarrhea myalgias

abdominal pain vomiting weakness blood eosinophilia

circumorbital edema myositis Muscular tenderness

Encystment stage recovery

51

Epidemiologiy

Cosmopolitan esp in Europe and North-America

China due to raw pork consumption

52

Diagnosis

Based on the basis of clinical symptoms and history and

eosinophilia

Etiological diagnosis

Biopsy of skeletal muscle

Immunological diagnosis (antibody detection)

10302017

27

Control methods

Hygienic education

Properly cooking pork

Low temperature storage of pork

(all larvae are killed at -15ordmC for 24hs)

Scientific raising pigs heat treatment of garbage used as pig

food

53

10302017

26

Pathogenesis

Main pathogenic factor larva

Invasion stage (intestinal phase) minor digestive

disturbance

Migration stage (muscular phase) diarrhea myalgias

abdominal pain vomiting weakness blood eosinophilia

circumorbital edema myositis Muscular tenderness

Encystment stage recovery

51

Epidemiologiy

Cosmopolitan esp in Europe and North-America

China due to raw pork consumption

52

Diagnosis

Based on the basis of clinical symptoms and history and

eosinophilia

Etiological diagnosis

Biopsy of skeletal muscle

Immunological diagnosis (antibody detection)

10302017

27

Control methods

Hygienic education

Properly cooking pork

Low temperature storage of pork

(all larvae are killed at -15ordmC for 24hs)

Scientific raising pigs heat treatment of garbage used as pig

food

53

10302017

27

Control methods

Hygienic education

Properly cooking pork

Low temperature storage of pork

(all larvae are killed at -15ordmC for 24hs)

Scientific raising pigs heat treatment of garbage used as pig

food

53