Helminthshippy training, questions,

7/23/2019 Helminthshippy training, questions,

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HELMINTHS

• Neglected Tropical Diseases: diseases that rather cause high mortality, cause high morbidity (global burden). Symptoms often associated

with social stigma (river blindness, guinea worm, lymphatic filariasis

• Impacts primarily school-age children (5-5 years old! which conse"uently causes impaired growth and development . #his leads to lasting

impact throughout adulthood.

• Schistosomiasis (.$% deaths and &.&' )*+syr! and oo%worm (no deaths &.' )*+syr! cause the most disease burden

/lassification of 0arasites 1 2u%aryotes3

. 4orms (helminths!: multicellular, largea. #ypes: nematodes, cestaodes, trematodes (flukes)

b. 4 6esolution (57.8! 1 “de-worming”!D" (mass drug administration9 especially to children! goes out to population and administers

;en<imida<oles everywhere once a year. owever, reinfection can still happen9 'ay help with brea%ing transmission cycles (especially for the

mos"uito-borne ones!9 also aims to improve sanitation and access to safe drin%ing water

. #roto$oa: unicellular, small (refer to other set of notes!

%ntestinal Nematodes (&oundworms)

- Unholy Trinity : ascariasis, trichariasis, hoo%worm

- *ong-lived: often survive for years in host and are generally soil transmitted- ost can be infected with multiple species

-*eads to eosinophilia: during tissue migration phases of helminths-/rude diagnosis via feces samples and loo%ing for eggs (si<e and morphology!.

- 'orbidity related to worm burden

- o not reproduce within human host (e=cept Strongyloides and Echinococcus!Organism Epidemiology Pathogenesis Clinical Manifestations Diagnosis T! other

"scaris

l#m$ricoides

(6oundworm!

>ery common. Life Cycle: ingest eggs enter

intestine and penetrate through the

blood stream travels to lungs,

reaching the throat when

swallowed, become adults and

remain in the SI9 ?eces can have

fertili<ed eggs, which are hardy and

last for years new infection

"scariasis. @sually asymptomatic.

0ulmonary phase: eosinophilic

pneumonitis, asthma-li%e

Intestinal phase: migration into biliary

(obstruction! and oral (e=pulsion! with high

loads,

/hronic infection: malnutrition, growth

retardation

: eggs in feces (eggs are

heat resistant!

#=: single dose of

anthelmintic drug

Trich#ris trichi#ria

(4hipworm!

Life Cycle: ingest eggs, but remain in

large intestine and develop there.#hin end embeds into colon, while

thic% end waves in lumen and

releases eggs.

ysentery syndrome, /olitis, &ectal

prolapse (usually only in heavyinfections!9 light infections generallyasymptomatic

: eggs in feces (bipolar

plugs!

#=: albenda<ole

% Necator

american#s &'()*

%"ncylostoma

d#odenale

(oo%worm!

)frica, South )merica,

)sia

'ost at ris%: children

and child-bearing aged

women

/utting plateshoo%s bite into intestine andcause disease feed on blood (ballows them to survive!. >ampires of thegut3

Life Cycle: *arvae in soil enter s%in of feet.

;urrow and enter blood stream. Ao

through lungs and develops after 0t

swallows into SI where it grows and

spreadsgets e=creted into soil

Iron deficiency : 4orm releases ?e into

lumen causing loss.

'ookworm infection

lood *oss

/hildren and child-age

bearing women at most

ris% because of low ?e

stores

: eggs in feces 1 canBt telldifference between the twospecies

#=: single dose of

antihelminic drug

/hronic infections (years!



Organism Epidemiology Pathogenesis Clinical Manifestations Diagnosis T!

"ncylostomacanin#m+$ra,ilien

se(dogcat hoo%worm!

?lorida, Aulf /oast,

/aribbean

0enetrate s%in only Larva Migrans: “Creeping eruption” 1 itchy

and irritation

=: /linical

#=: single dose of

antihelminic drug

Strongyloides

stercoralis

(threadworm!

#ropical C subtropical

regions of )frica, )sian,

*atin )merica9 %n +"ppalachians

&eseroir hosts. ogs

and non-human primates

Life Cycle: eveloped larvae in soil

penetrate skin enter circulatory

system Ao through lungs, trachea swallowed adult female worms

live in intestine where they deposit

eggs which can re-infect host (auto-

infection

! or be e=creted

female worms present in intestine canproduce eggs without malefertili<ation(parthenogenesis9 causinghyperinfection!

uto-infection cycle: can last decades

yperinfection: immunosuppressed athigher ris% larvae dissemination

Immunocompetent: asymptomatic usually

'ild AI symptoms, perianal rash due to

larva currens (migration through s%in,pulmonary migration causing

dyspneacough9 migratory infiltrates on

/D69 high peripheral eosinophilia

yperinfection: )cute enteritis (severe

diarrhea, ulcers in SI and *I9 ileus,

hemorrhage9 severe pulmonary

manifestation!

issemination: )berrant larvae migration

often carrying intestinal bacteria9 highmortality unless treated early

:

-0eripheral eosinophilia

-?ecal 2=amination:'icroscopy w larvae in

fresh stool or agar plate

with bacterial colonies

along trac% of migrating

larvae

-Serology

0revention: Screen

immunosuppressed,

improve sanitation,

minimi<e contact withcontaminated soil

Entero$i#s

(pinworm!

'ost common in children *ife /ycle: Ingest eggs hatch in SI

mature in colon females lay eggs on

perianal regionscratch crack, get

under nails, suck thumb, reinfect

-!erianal pruritits

-6estless sleep

-)berrant vaginal infection

-)ppendicle inflammation

: scotch tape test

#: )nthelmintic drug9 treat all

family members

To

!ocariasis

og and /at /ondition 1

humans infected

incidentally

0uerto 6ico

2ggs from canine feces deposited into

sandbo=es and playgrounds.

)ccidental ingestion (hopefully!

*arvae hatch in SI and penetrate wall

*arvae emerge and invade viscera

(liver, lungs, brain, and eye!9 o notdevelop into adult worms.

-isceral lar.a migrans (>*'!- in toddlers

-pneumonitis, hepatitis, cerebritis

(sei<ures!, eosinopihilia

Oc#lar lar.a migrans (*'! - E5 yo

-unilateral visual impairment which cancause permanent blindness

- differential: retinoblastoma or #;

"nisa/iasis

/an get from eating raw

fish.

Life Cycles: *& larvae are developed in

fish ingested by human 'atures

and burrows into stomach wall (dead

end host!

;y law, sushi must be flashfro<en to %ill this worm.

#=: 4ait until it dies or

remove endoscopically.



Tissue Nematodes (&oundworms)

'uman /ilariases. *ymphatic filariasis, nchoceriasis, loa loa, dracunculiasus

- ?emales produce larvae that migrate throughout blood, allowing for mos"uito to feed on and inFect into someone else


Trichinella

-Goonosis

-utbrea%s in

rawundercoo%ed meat

containing cysts (por%, bear, walrus and seal!

Life Cycle: Ingest meat with cyst

penetrates intestinal wall, develops,

and disseminates through lymph then

blood

2nters s%eletal muscle

iphasic

-Intestinal phase: AI symptoms

-Systemic: fever, myalgia, facial edema,

eosinophilia

: muscle biopsy, serology

#=: steroids (bc

inflammation! C anthelmintic

Lymphatic

filariasis

"uchereria

#ancrofti $%&'(

2ndemic in: )frica, S2

)siaIndia, 4estern

South )merica

#ransmitted by

mos0uito bite

0#chereria $ancrofti

worm causes 8H of

*?) but *rugia malayi)

timori in S2 )sia

/hildren often infected

young and carry for life

*arvae enter through bite wound ofmos"uito to *J and develop there obstruction and chronic lymphedema

9the worms enter the blood stream atnight where they can spread to amos"uito

-2arly: lymphangitis, lymphadenitis

Tropical #ulmonary 1osinophilia: young

men

-/hronic: lymphedema in e=tremities,breasts, and genitalia9 hydrocele andscrotal elephantiasis

o not treat with microfilaricide (2/! if

they have overlapping infection ofonchocerciasis or loiasis

Jot reversible.

: microfilariae in blood smear(at night

!9 )g detection9serology9 ultrasound of *J(worms moving (+ilaria ,anceSign!9 /linical suspicion

#=: /anBt %ill adult wormseasily so use prolonged andrepeat9 'icrofilaricide9 2/

'anage: interrupting

transmission via ') of

diethylcarbama<ine (2/! and

morbidity control

Onchoceriasis

)frica

#ransmitted by blac%fly.

-'assively reduced

prevalence due to ')

2nter s%in through blac%fly bite

migrate to subcutaneous tissues

forming nodules (including eye!fly

eats again and cycle restarts9 no blood

involvement in this condition

&ier lindness

/hronic infection of the subcutaneous

tissues, s%in, and eyes due to parasites

dying and releasing their )gpruritus,*),

dermatitis, ocular lesions (blindness)

: skin snips for

microfilariae9 palpable

onchoceromas

#=: ivermectin "K- months

Loa loa

6ainforest area of

4est/entral )frica

#ransmitted by Chrysops

fly.

2ntry into s%in and live in

subcutaneously affecting conFunctivae

and causing calabar swelling

2alabar swellings: angioedema, wormmoving around s%in (visually detectable!9

'ay cause inflammation.2ven across the eye3

: *);:microfilaria in blood

smear (during the day

!9

eosinophilia9/linical: visual inspection

#: 2/ or ivermectin9

surgery to remove worms

Drac#nc#l#s

medinensis

(Auinea worm!

'ali, /had, South

Sudan, 2thiopia

- 88.888 reduction in

disease since A4

eradication program

began (&.mil5H33!

)fter ingestion, larvae penetrates

intestine Slowly travels to

subcutaneous lower e=tremities and

grows

#ransmitted by water containing

copepods that have worm larvae.

-0ain and secondary infections at site ofworm leaving s%in.

-Super, super, super long worms.

6elatively eliminated via

filtering water education and

preventing infected people

from entering water.

=: clinical



#latyhelminths- /lukes (Trematodes)-water-borne infections with the snail as the obligate intermediate host

-'ost are food borne (e=ception: schistosomiasis!


S1 mansoni

S1 2aponic#m

S1 hemato$i#m

(Schistosoma!

)frica, South )merica,

)sia

/hildren especially (H-5 pea%!.

#ransmitted with s%in

contacting

contaminated fresh

water .

;* ?*@L2

*arvae %nown as cercariae leaves

snail, swims in water, and enters s%in

penetrate into blood vessels

eposit in SI and liver (a) 3& in

bladder (b) where they mature and lay

eggs which are shed in bowel

e=cretion

(a) S mansoni) S .aponicum

(b) S hemato#ium

)/@#2:SwimmerBs itch:--7hrs after infection9 intensely pruritic

urticarial rash which lasts a few days Latayama fever-7-Mw%s after infection9 egg deposition by adultworms begins which can cause hypotension,shoc%, and eosinophilia9 treat with pra$i0uantel4- steroids

/6JI/: +ears post infection

-igh worm burden with egg deposition over yrs

-Aranulomas form in AI t ract, liver, bladder

-S mansoni/.aponicum: periportal fibrosis9

portal hypertension, abdominal pain, AI

blood loss,

-S haemato#ium: obstructie uropathy

(fibrosis!, bladder carcinoma9 genital tract

involvement increases I> ris% in females and

can lead to infertility

-6arely involves /JS

:/;/: eosinophilia,

@rineStool sample for eggs9serology

(S hemato#ium hasterminal spine while Smansoni has lateral spine!

#=: 0ra<i"uantel for E7yo9

used in ') programs

%Clonorchis

%Opisthorchis

/hina and S2 )sia

#ransmitted via

uncooked freshwater

fish5

6I2J#)* *I>26 ?*@L2

2ncyst worm obtained from fish releases

and travels up bile ductmatures *ives in

bile duct of liver causing fibrosis e=creted

through feces

)cute: fever, abdominal pain,hepatomegaly, eosinophilia /hronic: recurrent ascending cholangitis

and pancreatitis, cholangiocarcinoma ,

biliary fibrosis

#=: 0ra<i"uantel

3asciola hepatica

;olivia, 0eru, 2cuador,

Iran, 2gypt#ransmitted via

watercress (water

plant)

42S#26J *I>26 ?*@L2

2ncyst worm obtained from watercress

releases and travels up bile ductmatures

*ives in bile duct of liver causing

fibrosis e=creted through feces

)cute: abdominal pain (6@N!,

eosinophilia

/hronic: destruction of liver

parenchyma

=: @ltrasound/#serology

#=: )nthelmintic

Paragonim#s

4estermni

0aragonimiasis

/hina, 0hilippines

#ransmitted via crab or

crayfish5

*@JA ?*@L2 /hest pain, hemoptysis, cough9 presence

of pulmonary infiltrates on /D6

: eggs in sputum

#=: 0ra<i"uantel



#latyhelminths - 2estodes (Tapeworms)-?ood-borne infections

-)dult tapeworms have low pathogenicity, but the laral tapeworm infections cause much more problems (such as sei<ures!. -2very continent e=cept for )ntarctica.


Taenia

%T1 saginata

%T1 soli#m

@ndercoo%ed beef(saginata! or por%(solium!.

umans are the sole

definitive host, but pigs

(soli#m (, cows

(saginata* can be

intermediate hosts

)dult: /yst containing larvae in meat

muscle Ingestion causing release

into SI and develops until adult form

ead (scole=! imbeds in gut andformed eggs are e=creted.

/ysticerosis (alternative #. solium

route!: uman ingests egg that has

been released from feces. *arvae

released and penetrates throughout

body and creates cysts.

isseminates throughout all

tissuesorgans and causes

holesinflammation.

/ysticeri (solium larvae! presente=traneurally in s%eletal muscles and

subcutaneous tissue or in brain(neurocysticercosis9 sei<uresconvulsions!9cycticercus O lesion which causesinflammatory response on death thatcauses sei<ure

Jote: solium get up to Km long and live 5years3

Jeurocysticercosis =:

/#'6I, serology

Jeurocysticercosis #=: noneif lesion calcified9 if viable

pra<i"antel or albenda<ole

for months9 steroids and

surgery may be necessary

0revent via pig vaccination,

personal hygiene, meat

inspections, thoroughly

coo%ing meat, proper

sanitation

Diphyllo$othri#m

lat#m(Diphyllobothraisis)

Intermediate host:

/opepod and freshwater

fish

)las%a, /anada, Areat

*a%es, Scandinavia

>ague abdominal pain

!egaloblastic anemia and pernicious

anemia (worm uses ; causing anemia in

host!.

Echinococc#s

gran#los#s('ydatid disease)

4orldwide distribution

og is definitive host,

sheep and humans are

intermediate hosts

Ingest egg9 possibly being li%ed by dog

in mouth 6eleases larvae and

disseminates to the liver, lungs, other

sites causing cysts

/ystic lesions (hyatid cysts! in liver, lungs,and other sites which can causeobstruction and possible allergic reactionwhen they rupture9 ;eware if surgery3

'ydatid Disease: slow growing cystictumor in liver, lung, brain

: /#'6I, ultrasound,

serology

#=:

)lbenda<ole for months or

surgery to remove large

cysts (#uncture cyst,

"spirate cyst, %nFect

chemicals, &e-aspiration!

0revention: e-worm dogs9

avoid feeding infected

sheep to dogs

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