Lecture 01 - Introduction to Parasitology

8/19/2019 Lecture 01 - Introduction to Parasitology

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INTRODUCTIONINTRODUCTION

ININ

PARASITOLOGYPARASITOLOGY

Assoc. Prof. Dr. Carmen-Michaela Cretu

MD, PhD, DTM&HCTH ®

“Carol Davila” University of Medicine and PharmacyBucharest


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PARASITESPARASITESPARASITIC DISEASESPARASITIC DISEASES

Parasites are very common all over the world, in

humans, animals and vegetables as well.

Concerning their relationship with the host, in these

associations, there are some kind of interactions, the

benefit being on one side (host), on the other one

(parasite), or, rarely, on both sides.

It is a strong interaction between host and parasite


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The importance of parasiticThe importance of parasiticdiseasesdiseases

The parasitic diseases can have an acuteacuteevolutionevolution, even up to death:

- Malaria represents the third cause of death in theworld, among the infectious diseases.

- African trypanosomiasis or visceral leishmaniasisare very dangerous, arriving even to death, in theabsence of the specific treatment

Other parasitic diseases, are associated withchronic evolution, representing an importantsource of morbidity (i.e. chronic schistosomiasis)


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DracontiasisTemporary inability for workingCutaneous leishmaniasisSkin / mucosa sore

SchistosomiasisSecondary sterility

Malaria, schistosomiasisKidney damage

Schistosomiasis, opistorchiasisLiver cirrhosis

Cysticercosis, VLM, Malaria, SchistosoSeizures

Toxoplasmosis, Oncocerchiasis, OLM,Cysticercosis, Achantamoeba keratitis,

Vision troubles / blindness

Chagas’ disease, Trichinellosis, VLMCardiac disturbances

AscaridiasisIntestinal occlusion

Opistorchiasis, schistosomiasis(S. haematobium )

Gall bladder, or urinary malignances

Malaria, hook wormsIron deficiency anemia

Intestinal parasites (worms)Decreasing the intellectualdevelopment

Intestinal helmints / protozoaMalnourishment, chronic diarrhea

Malaria, Chagas’ diseaseBlood transfusion diseases

Toxoplasmosis, Chagas’ diseaseCongenital malformations

PARASITIC DISEASES MORBIDITY


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7 0001.7 million200 millionSchistosomiasis

40 millionFlukes

4,7 million120 millionLymphatic filariasis

1 million18 millionOnchocercosis

65 0001.7 million1.3 billiardHook worms infection

60 0001.3 million1.5 billiardAscaridiasis

70 0001.5 billionAmoebiasis

40 0001.3 million0.3-0.5 millionAfrican trypanosomiasis

42 0001.7 million12 millionLeishmaniasis

17 000600 00016-18 millionChagas’ disease

1.5-2.7 million39 million300-500 millionMalaria

Mortality /Mortality /year year

Morbidity Morbidity InfectedInfectedpersons persons

Parasitic disease Parasitic disease

TROPICAL AND DEVELOPING COUNTRIESTROPICAL AND DEVELOPING COUNTRIES- Parasitic diseases represent an important target for internationalorganisms involved in Public Health surveillance- It is estimated that about 33% of the human population is under the riskof parasitic diseases, mainly those living in inter-tropical areas


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DEVELOPED COUNTRIESDEVELOPED COUNTRIES Despite the good hygiene level, water supply, vector control,

some parasitic diseases can appear in these countries, either

as epidemic, or sporadic cases This situation seems to be linked to:

- Professional field

- Recreation/business voyages in tropical areas,

change of the nutrition style (i.e. eating raw or improperlycooked meat – taeniasis/cysticercosis, trichinellosis or fish –anisakiasis)

- Life in collectivities (giardiasis epidemics in kindergartens)

- Multiple causes of immune suppression (reactivation of anancient infection - cerebral toxoplasmosis, visceral

leishmaniasis - in HIV patients, or acquiring a new pathogen

like Cryptosporidium parvum, Encephalitozoon intestinalis,

Enterocytozoon bienusi)


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EMERGING PARASITIC DISEASES:EMERGING PARASITIC DISEASES:some well known parasitic diseases which can beeasily spread and become frequent:

Due to the climate changes, malaria parasites can be spreadin areas where the disease was initially eradicated:

The climate consequences of El Niño in 1997 was followedby a malaria epidemic in Kenya

The war and social troubles in Africa can explain theincreasing cases in African trypanosomiasis and theresidual foci of dracunculiasis in Sudan

The field irrigation in tropical areas are facilitating theoccurrence of malaria or schistosomiasis infection in these

regions The increase of air transport (for persons or commercial

flights) may facilitate the transport of the parasites from ageographic area to another: ”airport malaria”Commercialized infected meat with Trichinella spp ., the

importation of raspberry contaminated with Cyclospora,from Guatemala to US


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DEFINITIONS

Definitive Host : Worms - Harbors Mature Parasite

Protozoa - Harbors Sexually Reproducing Stage

Intermediate Host : Worms - Harbors the Immature ParasiteProtozoa - Harbors Asexually Reproducing Stage

Reservoir Host : Non-Human host which maintains the infection in nature

Vector: Transmits parasite from one host to the next one

Usually a Arthropod - Parasite undergoes compulsory life cycle

development

Transport Host: Direct transmission of the parasite i.e. fecal

contamination by flies

Parasite: organism living together with the host,depending totally or partially on it, but withoutdestroying the host: protozoa, metazoan (worms)


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ZoonosisZoonosis:: a common disease to human and domestic orsylvatic animals as well (trichinellosis, schistosomiasis,toxoplasmosis)

Parasite specificityParasite specificity - the capacity of a parasite to develop in a

certain host (or a host group)

The specificity is variable:

- poor or inexistent (toxoplasmosis, trichinellosis)

- moderate (fascioliasis)

- high (enterobiasis)

The specificity is variable upon the host:

i.e. malaria parasite is very specific for human, but less specificfor mosquito (there are several anopheles species known asmalarial vectors)

As a rule:

a disease due to a well adapted parasite has a better tolerancein the host than a disease due to a less adapted parasite


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HOSTHOST--PARASITE RELATIONSHIPPARASITE RELATIONSHIP

Saprophyte:Saprophyte: organism living in the nature

on any decomposing material SymbiosisSymbiosis:: some organisms living

together, in association, this kind of lifebeing profitable for both of them

CommensalCommensal:: organism living in contactwith the host, without causing anydisturbances or benefit in host’s life style

PredatorPredator:: organism living initially togetherwith the host, but finally killing the host inorder to nourish himself


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PARASITESPARASITES

EctoparasitesEctoparasites:: are living on the body surface, skin, of the host

- Determining by themselves a skin disease, as S. scabies

- Acting as vectors for some parasitic diseases (mosquitoes, flies

- Producing a local, temporary reaction (louse)

EndoparasitesEndoparasites:: are living inside the body host – tissues, blood,

intestine, etc

Parasite location in the host: Parasite location in the host: - can live only in a certain, elective organelective organ of the host: digestivesystem (intestinal parasites), liver (Fasciola spp .), blood(Plasmodium spp.), skin (Sarcoptes spp )

- can live in a not habitual organ – critique sitecritique site – or, they canmigratemigrate in different organs, when the parasite is not very welladapted to the host, which serves to him only for the transport -

paratenicparatenic hosthost (larva migrans syndrome due to the dog’s Ascaris migration)


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HOSTHOST--PARASITE RELATIONSHIPPARASITE RELATIONSHIP

Compulsory parasitic lifeCompulsory parasitic life - some parasites alwaysneed a host for surviving and living

Optional parasitic lifeOptional parasitic life - some parasites use to liveas saprophytes in nature and they become parasitesunder certain circumstances

Accidental parasitic lifeAccidental parasitic life - some parasites are livingas free organisms, rarely becoming parasites


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PARASITIC INFECTIONSPARASITIC INFECTIONSPATHOGENESISPATHOGENESIS

Human can be host to over 100 kinds

of parasites

Parasitology - largely a study of

symbiosis

When the symbiont is harming thehost, it becomes a parasite


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FEATURES OF PARASITICFEATURES OF PARASITICINFECTIONSINFECTIONS

Host immune response

Geographical region

Parasitic burden

First/secondary infection

Associated pathology of the host


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TRANSMISSIONTRANSMISSION

Directly,Directly, without any intervention - person to persontransmission (giardiasis, enterobiasis)

IndirectlyIndirectly, by the intervention of an external factor:

- Environment (soil – ascaridiasis, trichuriasis)

- Passive organism (transport host – insects, or vegetables)- Active transmission (vector – mosquito, fly)


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TRANSMISSIONTRANSMISSION

Oral contamination Skin penetration

Vector transmission

Sexual transmission

Blood transfusion / organ transplant

Vertical transmission (mother to child)

Other types of contamination


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1. Oral transmission1. Oral transmission

A.A. Water, food contaminated by cysts, eggs or larvae: Water, food contaminated by cysts, eggs or larvae:

E. hystolityca Giardia duodenalis

Balantidium coli

Cryptosporidium spp.

Toxoplasma spp.

Cyclospora spp.

Microspora spp .

Ascaris lumbricoides Enterobius vermicularis

Trichuris trichura

Hydatid cyst

Cysticercus /coenurus

Hymenolepis spp.

Toxocara spp.

Fasciola hepatica

Dracunculus medinensis

ProtozoaProtozoa MetazoaMetazoa


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B. Improperly cooked meat / fish containing parasitic larvae: B. Improperly cooked meat / fish containing parasitic larvae:

Meat- Trichinella spp.

- Taenia spp.

(T. saginata, T. solium)

- Toxoplasma gondii - Sarcocystis spp.

- Gnathostoma spinigerum

Fish- Opistorchis / Clonorchis

- Paragonimus spp.

- Capilaria philipinensis

- Anisakiasis - Angiostrongylus spp.

- Diphilobotrium spp.

- Heterophies heterophies /

Metagonimus yocogaway

- Gnatostoma spinigerum

- Sparganum


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2. Skin penetration2. Skin penetrationdirect penetrationof the living larvae from water / soil, following the skin contact

Schistosoma spp.

A. duodenale / N. americanus; S stercoralis

Myasis

Cutaneous Larva Migrans

Sarcoptes Scabiei

Tunga penetrans


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3. Vector transmission3. Vector transmissionskin bite / contamination by a haematophagus vector

Skin bite

Plasmodium spp.

Babesia spp.

T. brucei rhodesiense / gambiense

Leishmania spp.

Wuchereria bancrofty /

Brugia malayi

Onchocerca volvulus, Loa loa

Skin contamination

Trypanosoma cruzi


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4.4. SexualSexual transmissiontransmissionEndoparasites

Trichomonas vaginalis

Entamoeba histolytica

Ectoparasites

Phtirius pubis

Sarcoptes scabies

5. Blood transfusion / organ5. Blood transfusion / organ

transplanttransplant Plasmodium spp.

Trypanosoma cruzi Toxoplasma gondii

(primary / ancient, reactivated infection)


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6. Vertical transmission6. Vertical transmission(mother to child)

Toxoplasma gondii Trypanosoma cruzi

P. falciparum

7. Other type of contamination7. Other type of contaminationFree living amoeba

Acantamoeba spp.

Naegleria spp.


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DracontiasisTemporary inability for workingCutaneous leishmaniasisSkin / mucosa sore

SchistosomiasisSecondary sterility

Malaria, SchistosomiasisKidney damage

Schistosomiasis, OpistorchiasisLiver cirrhosisCysticercosis, VLM, Malaria, SchistosomiasisSeizures

Toxoplasmosis, Oncocerchiasis, OLM,Cysticercosis, Achantamoeba keratitis

Vision troubles / blindness

Chagas’ disease, Trichinellosis, VLMCardiac disturbances

AscaridiasisIntestinal occlusion

Opistorchiasis, Schistosomiasis(S. haematobium )

Gall bladder, or urinary malignances

Malaria, hook wormsIron deficiency anemia

Intestinal parasites (worms)Decreasing the intellectualdevelopment

Intestinal helmints / protozoaMalnourish, chronic diarrhea

Malaria, Chagas’ diseaseBlood transfusion diseases

Toxoplasmosis, Chagas’ diseaseCongenital malformations

EFFECTS ON THE HOSTEFFECTS ON THE HOST


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W. bancrofti

S. stercoralis

T. gondii

T. Gambiense

T. cruzi

Leishmania spp.Plasmodium spp.

Lymph nodesSpleen

Bone marrow

T. canis A. lumbricoides

E. granulosus E. multilocularis

S. mansoni Opistorchis spp.

F. Hepatica E. Granulosus

S. mansoni

Plasmodium spp.T. gondii

E. histolytica T. gambiense

Leishmania spp.Microsporidia

Plasmodium spp.

Liver /Bile ducts

Trichinella spp.Dirofilaria immitis

T. solium (cysticercosis)

E. granulosus

H. heterophyes

Toxoplasma gondii T. cruzi

T. b. rhodesiense

Heart

Toxocara spp.A. lumbricoides

W. bancrofti Dirofilaria immitis S. stercoralis

A. duodenale / N. Americanus

E. granulosus Schistosoma spp.

Paragonimus spp.

Toxoplasma gondii Plasmodium spp.

E. histolytica P. carinii x

C. parvum x

Lung

Hypoderma spp.Demodex

Foliculorum Phtyrius pubis

Toxocara spp.Loa loa

O. volvulus Thelazia spp.Dirofilaria repens


Spirometra spp.

Acantamoeba spp.Toxoplasma gondii

T. cruzi

Eye

Hypoderma spp .

Toxocara spp.Trichinella spp.A. cantonensis

Loa loa


E. granulosis

Schistosoma spp.Paragonimus spp.

Multiceps spp.H. heterophyes

Plasmodium spp Babesia spp T. b. Gambiense

Naegleria spp.Acantamoeba spp.

Toxoplasma gondii

CNS

ArthropodaNematodaPlat-helmintsProtozoaParasiteOrgan

PP

AA

RR

AA

SS

II

TT

EE

SS’’

LL

OO

CC

AA

TT

II

OO

NN


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S. scabiei S. penetrans Cordilobia

spp.Dermatobia

spp.Pediculus

spp.Phtirius

pubis

Demodex foliculorum

Loa loa O. volvulus D. medinensis

Dirofilaria repens S. stercoralis A.brasiliense A.caninum

Gnathostoma spp A. costaricensis

Schistosoma spp.Spirometra spp.

T. gondii Leishmania spp.

Skin

E. vermicularis A.lumbricoides A.duodenale N. americanus S. stercoralis Trichuris trichiura

Anisakis Capilaria

philipinensis Trichinella spp

T. solium T. saginata H. nanaD. latum Fasciolopsis buski H. heterophyes

S. mansoni S. japonicum S. intercalatum

E. histolytica Giardia intestinalis Balantidium coli Isospora belli Cryptosporydium

parvum

Cyclospora spp.Microsporidia Dientamoeba

fragillis

Intesinal lumen

Phtirius pubis

S. scabiei

E. vermicularis W. bancrofti

S. haematobium T. vaginalis E. histolytica

Genital -urinary system

Loa loa E. granulosus S. mansoni

Plasmodium spp.Microsporidia

Kidneyparenchima

Trichinella spp.

Toxocara spp.

T. solium

(cysticercosis)

T. cruzi

Sarcocystis spp.T. Gondii Sarcocystis spp.

Muscles


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PARASITIC INFECTIONPARASITIC INFECTIONPathogenesisPathogenesis -- Mechanisms for host injury

Eliciting an Immune Response: hookworm larvae in the lungs causeeosinophilic pneumonia

Mechanical injury - trauma:- hookworm larvae, insect bite, schistosoma eggs during migration

- choledochal occlusion by ascaris, fasciola

- appendicitis due to ascaris, trichiuris, enterobius

- compression on surrounding anatomical structures: hidatid cyst, cysticercus

Nutritional depletion: adult hookworms, ascaris, giardia lamblia

Digestion of host tissues: Entamoeba histolytica

Toxins and toxic metabolites:

- Plasmodium, pruritus due to sarcoptes female migration

- anal pruritus due to E. vermicularis egg deposition- toxins inoculated by insect bite

Behaviour changes: ascaris, enterobius, teniasis, giardiasis

Combinations of the above are common


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How the parasite iseliminated by the host?

Through feces - all the intestinal parasites:

nematodes, cestodes, protozoa, eliminating: eggs

(infective or not), larvae, cysts

Through the genital-urinary tract: Schistosoma

haematobium, Trichomonas vaginalis

By haematophagus insects, for the blood parasites:

Anopheles spp. for Plasmodium spp., or

Phlebotomus spp. for Leishmaniasis For the deep tissue parasites sometimes it is

necessary a predator – ingestion of pork meat

containing Cysticercus spp ., or Trichinella larvae


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How the parasite can avoidHow the parasite can avoid

the host reactionthe host reaction…… Anatomical separationAnatomical separation by an antigenic amorphous, but permeable structure for

the nutrients (external host layer of the hydatid cyst, collagen capsule of the

muscle fiber, containing Trichinella larvae)

Thick cuticleThick cuticle of the worms

Resistance to the complementResistance to the complement cytotoxiccytotoxic activityactivity

Inhibition of the liposome fusion by the intracellular parasitesInhibition of the liposome fusion by the intracellular parasites –T. gondii

Synthesis by the worms of some proteasesSynthesis by the worms of some proteases destroying the antibodiesantibodies

Host antigens acquisitionHost antigens acquisition (blood group substances on Schistosoma spp .

adults surface, filarial worms)

Antigenic variationAntigenic variation (in T. brucei, P. carinii etc)

ImmuneImmune--suppressionsuppression (lymphocytotoxines secreted by Trichinella spp.)

Surface antigens specific for certain stages of the parasitesSurface antigens specific for certain stages of the parasites (lymphatic(lymphatic

filariasisfilariasis))


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Host reaction to the parasiteHost reaction to the parasite……

EncapsulationEncapsulation (Trichinellosis, Cysticercosis)

Calcium depositingCalcium depositing (Trichinellosis, Cysticercosis)

InflamationInflamation -- granuloma formationgranuloma formation (Toxocariasis,

Schistosomiasis) Included intracellularIncluded intracellular (Toxoplasma gondii, Leishmania

spp., T. cruzi )

Tissue reaction:Tissue reaction:- hypertrophy – billiary tree due to Fasciola hepatica

- neoplasia – papilloma and bladder cancer in urinary

Schistosomiasis


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Parasitic diseases can occur:Parasitic diseases can occur:

SporadicSporadic – isolated cases, without any connection

EndemicEndemic – the continuously persistence of thedisease, with a minimum morbidity and seasonal

appearance

HyperendemicHyperendemic – endemic, with high morbidity EpidemicEpidemic - a rapid extension of the disease,

including an important number of population

EndemoEndemo--epidemicepidemic – periodical epidemics in anendemic area

PandemicPandemic – epidemic, with extension at large

areas of the world


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PARASITES

PROTOSOA METASOA

Sporozoa

• Sporozoans

Sarcodina

• AmoebasPlathelminthes

• Flatworms

Nemathelminthes

• Roundworms

Mastigophora

• Flagellates

Ciliates

• Ciliates

Trematoda

• Flukes

Cestoda

• Tapeworms


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IMPORTANT ENDOPARASITES IN HUMAN PATHOLOGY

PROTOZOAPHYLUM RHIZOFLAGELATAE

Order RhizopodaEntamoeba histolytica

Entamoeba hartmanni Entamoeba coli Entamoeba gingivalis

Entamoeba polecki Iodamoeba butschlii Dientamoeba fragilis Endolimax nana Naegleria fowleri

Acanthamoeba spp .

Order FlagellataTrypanosoma brucei

gambiense

Trypanosoma brucei rhodesiense

Trypanosoma cruzi Leishmania donovani Leishmania tropica

Leishmania brasiliensis Leishmania mexicana Trichomonas vaginalis

Trichomonas intestina lisTrichomonas tenax

(bucalis) Chilomastix mesnili Retortamonas

(Embadomonas) intestinalis

Enteromonas hominis

Giardia duodenalis


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IMPORTANT ENDOPARASITES IN HUMAN PATHOLOGYIMPORTANT ENDOPARASITES IN HUMAN PATHOLOGY

PHYLUM SPOROZOA PHYLUM MICROSPORIDI PHYLUM SPOROZOA PHYLUM MICROSPORIDI AA

HaematozoaPlasmodium spp.

Plasmodium falciparum Plasmodium vivax Plasmodium malariae Plasmodium ovale

Babesia spp .CoccidiaSarcocystis hominis Isospora belli Cryptosporidium parvum

Toxoplasma gondii Cyclospora spp.

Nosema spp.

Encephalitozoon spp.Enterocytozoon spp.Pleistophora spp.Septata spp.

PHYLUM CILIATAPHYLUM CILIATA

Balantidium spp

UNCERTAIN TAXONOMY UNCERTAIN TAXONOMY

Pneumocystis carinii Blastocystis hominis


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PHYLUM PLATHELMINTH PHYLUM PLATHELMINTH

OrderOrder TrematodaTrematodaDistoma

Fasciola hepatica

Dicrocoelium dendriticum

Clonorchis sinensis

Opisthorchis felineus

Fasciolopsis buski

Echinostoma spp.

Heterophyes heterophyes

Metagonimus yokogawai

Paragonimus westermanni :

Schistosoma

Schistosoma haematobium

Schistosoma mansoni

Schistosoma intercalatum

Schistosoma japonicum

Schistosoma mekongi

OrderOrder CestodaCestodaTaenia saginata

Taenia solium

Diphyllobothrium latu m

Spirometra spp

Echinococcus granulosus Echinococcus multiloculari s

Hymenolepis nana

Hymenolepis diminuta

Dipylidium caninum


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PHYLUM NEMATODAPHYLUM NEMATODA PHYLUM PARARTHROPODA

OrderOrder NematodaNematodaTrichuris trichiura Enterobius vermicularis Ascaris lumbricoides Ancylostoma duodenale Necator americanus :Strongyloides stercoralis :

Toxocara spp.Anisakys spp.Capillaria hepatica Angiostrongylus cantonensis Gnathostoma spp .Trichostrongylus spp .Trichinella spiralis

Wuchereria bancrofti Wuchereria pacifica Brugia malayi Loa loa Onchocerca volvulus Dracunculus medinensis

Mansonella spp

OrderOrder PentastomaPentastomaLinguatula serrata Armillifer spp.


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IMPORTANT ECTOPARASITES IN HUMAN PATHOLOGYIMPORTANT ECTOPARASITES IN HUMAN PATHOLOGY

PHYLUMPHYLUM ARTHROPODAARTHROPODAOrder InsectOrder Insect OrderOrder Arachnidae Arachnidae

Anoploura (louse)Pediculus humanus

corporis Pediculus

Phthirus pubis

Trichodectes canis

Hemiptera (bugs)Cimex lectularius

Cimex hemipterus

Triatoma infestans Triatoma megista

Rhodnius prolixusAphaniptera (flea)

Pulex irritans Xenopsylla cheopis Nosophyllus fasciatus

Ctenocephalides canis Tunga penetrans

Acarina

IxodidesIxodes ricinus Ixodes scapularis

SarcoptidaeSarcoptes scabiei

DemodicideDemodex

folliculorum

OrderOrder CrustaceeaCrustaceea

Cyclops spp Diaptomus spp.

Diptera (fly, mosquito, phlebotomus)

Anopheles spp.

Culex spp.Mansonia spp.

Aedes spp.

Phlebotomus spp.

Lutzomya spp.Simulium spp.

Chrysops spp.Glossina spp.

Calliphora spp.Lucillia spp.

Gastetrophilus spp.

Cordylobia spp.Auchmeromyia spp.

Cochliomyia spp .Oestrus spp .Sarcophaga spp .Hypoderma spp .

Dermatobia spp .Wolhlfahrtia spp


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When a doctor should thinkabout a parasitic disease?

… should have into consideration a parasitic disease, becausethere are a lot of clinical situations related to the parasites:

There are a lot of organs (liver, CNS, eye, skin, lung, etc) and

many medical specialties (neurology, ophthalmology,dermatology, pediatrics, chest diseases, allergology, surgery,infectious diseases, etc…) involved

Travel medicine push the medical doctors to ask their patients

about their travels (duty or holiday), the duration, theaccommodation; the importance of the medical advice beforedeparture and after return, in order to look for the mostimportant diseases common in the respective areas

The well knowledge of the geographic area where the patientshad travel, allows the doctor to suspect or to eliminate a parasite


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Teniasis

Hymenolepis nana

Trichinella spp.

Trichuris trichura

S. stercoralis E. vermicularis

Paragonimus

africanus

Gnathostoma

spinigerum

A. lumbricoides

S. haematobium S. mansoni S. intercalatum

Angiostrongylus cantonensis

A. duodenale / N. americanus

Onchocerca

volvulus

Fasciolopsis buschi Giardia duodenalis

Angiostrongylus spp.Dracunculus medinensis

Paragonimus westermanii

Toxoplasma gondii

S. mansoni Loa loa Wuchereria bancrofti Brugia malayi

Trichomonas spp.Oncocerca volvulus Wuchereria bancrofti Capillaria philippinensis Microsporidiasis

T. cruzi T. brucei S. japonicum Cyclospora

L. mexicana /L. brasiliense

Leishmania spp (cutaneous, visceral)

Opistorchis felineus Cryptosporidium spp.

Malaria Malaria Malaria E. histolytica South America Africa Asia Cosmopolite

GEOGRAPHICAL DISTRIBUTION OF THE MOST IMPORTANT PARASITESGEOGRAPHICAL DISTRIBUTION OF THE MOST IMPORTANT PARASITES

Lecture 01 - Introduction to Parasitology

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