List of parasites of humans


Endoparasites

Protozoan organisms

Common name of organism or diseaseLatin name Body parts affectedDiagnostic specimenPrevalenceSource/Transmission
Granulomatous amoebic encephalitis and Acanthamoeba keratitis Acanthamoeba spp.eye, brain, skincultureworldwidecontact lenses cleaned with contaminated tap water
Granulomatous amoebic encephalitisBalamuthia mandrillarisbrain, skincultureworldwidevia inhalation or skin lesion
BabesiosisBabesia B. divergens, B. bigemina, B. equi, B. microfti, B. duncanired blood cellsGiemsa-stained thin blood smearNew England tick bites, e.g. Ixodes scapularis
BalantidiasisBalantidium coliintestinal mucosa, may become invasive in some patientsstool ingestion of cyst, zoonotic infection acquired from pigs
BlastocystosisBlastocystis spp.intestinaldirect microscopy of stool worldwide: one of the most common human parasites
Developing regions: infects of the total populations		eating food contaminated with feces from an infected human or animal
CryptosporidiosisCryptosporidium spp.intestinesstoolwidespreadingestion of oocyst, some species are zoonotic
CyclosporiasisCyclospora cayetanensisintestinesstoolUnited Statesingestion of oocyst thru contaminated food
DientamoebiasisDientamoeba fragilisintestinesstoolup to 10% in industrialized countriesingesting water or food contaminated with feces
AmoebiasisEntamoeba histolyticaintestines stool areas with poor sanitation, high population density and tropical regionsfecal-oral transmission of cyst, not amoeba
GiardiasisGiardia lamblialumen of the small intestinestoolworldwide?ingestion of water containing deer or beaver feces
IsosporiasisIsospora belliepithelial cells of small intestinesstoolworldwide – less common than Toxoplasma or Cryptosporidiumfecal oral route – ingestion of sporulated oocyst
LeishmaniasisLeishmania spp.cutaneous, mucocutaneous, or visceralvisual identification of lesion or microscopic stain with Leishman's or Giemsa's stainvisceral leishmaniasis – worldwide; cutaneous leishmaniasis – Old World; mucocutaneous leishmaniasis – New WorldPhlebotomus, Lutzomyia – bite of several species of phlebotomine sandflies
Primary amoebic meningoencephalitis Naegleria fowleribraincultureunknown, but infection is rarenasal insufflation of contaminated warm fresh water, poorly chlorinated swimming pools, hot springs, soil
MalariaPlasmodium falciparum, Plasmodium vivax, Plasmodium ovale curtisi, Plasmodium ovale wallikeri, Plasmodium malariae, Plasmodium knowlesired blood cells, liverblood filmtropical – 250 million cases/yearAnopheles mosquito
RhinosporidiosisRhinosporidium seeberinose, nasopharynxbiopsyIndia and Sri Lankanasal mucosa came into contact with infected material through bathing in common ponds
SarcocystosisSarcocystis bovihominis,Sarcocystis suihominisintestine, musclemuscle biopsywidespreadingestion of uncooked/undercooked beef/pork with Sarcocystis sarcocysts
Toxoplasmosis Toxoplasma gondiieyes, brain, heart, liverblood and PCRworldwide: one of the most common human parasites; estimated to infect between of the global population.ingestion of uncooked/undercooked pork/lamb/goat with Toxoplasma bradyzoites, ingestion of raw milk with Toxoplasma tachyzoites, ingestion of contaminated water food or soil with oocysts in cat feces that is more than one day old
TrichomoniasisTrichomonas vaginalisfemale urogenital tract microscopic examination of genital swabworldwidesexually transmitted infection – only trophozoite form
Sleeping sicknessTrypanosoma bruceibrain and bloodmicroscopic examination of chancre fluid, lymph node aspirates, blood, bone marrow50,000 to 70,000 people; only found in Africatsetse fly, day-biting fly of the genus Glossina
Chagas diseaseTrypanosoma cruzicolon, esophagus, heart, nerves, muscle and bloodGiemsa stain – bloodMexico, Central America, South America – 16–18 millionTriatoma/Reduviidae – "kissing bug" insect vector, feeds at night

Helminths (worms)

Helminth organisms include:

Tapeworms

Common name of organism or diseaseLatin name Body parts affectedDiagnostic specimenPrevalenceTransmission/Vector
Tapeworm – Tapeworm infectionCestoda, Taenia multicepsintestinestoolrare worldwide
Diphyllobothriasis – tapewormDiphyllobothrium latumintestines, bloodstool Europe, Japan, Uganda, Peru, Chileingestion of raw fresh water fish
Echinococcosis – tapewormEchinococcus granulosus, Echinococcus multilocularis, E. vogeli, E. oligarthrusliver, lungs, kidney, spleenimaging of hydatid cysts in the liver, lungs, kidney and spleenMediterranean countriesas intermediate host, ingestion of material contaminated by feces from a carnivore; as definite host, ingestion of uncooked meat from a herbivore
HymenolepiasisHymenolepis nana, Hymenolepis diminutaingestion of material contaminated by flour beetles, mealworms, cockroaches
Beef tapewormTaenia saginataIntestinesstoolworldwide distributioningestion of undercooked beef
Cysticercosis-Pork tapewormTaenia soliumBrain, muscle, Eye stool, bloodAsia, Africa, South America, Southern Europe, North America.ingestion of undercooked pork
BertielliasisBertiella mucronata, Bertiella studeriIntestinesstoolrarecontact with non-human primates
SparganosisSpirometra erinaceieuropaeiingestion of material contaminated with infected dog or cat feces

Flukes

Common name of organism or diseaseLatin name Body parts affectedDiagnostic specimenPrevalenceTransmission/Vector
ClonorchiasisClonorchis sinensis; Clonorchis viverrinigall bladder ducts and inflammation of liverEast Asiaingestion of under prepared freshwater fish
Lancet liver flukeDicrocoelium dendriticumgall bladderrareingestion of ants
Liver fluke – FasciolosisFasciola hepatica, Fasciola giganticaliver, gall bladderstoolFasciola hepatica in Europe, Africa, Australia, the Americas and Oceania; Fasciola gigantica only in Africa and Asia, 2.4 million people infected by both speciesfreshwater snails
Fasciolopsiasis – intestinal flukeFasciolopsis buskiintestinesstool or vomitus East Asia – 10 million peopleingestion of infested water plants or water
Metagonimiasis – intestinal flukeMetagonimus yokogawaistoolSiberia, Manchuria, Balkan states, Israel, Spainingestion of undercooked or salted fish
MetorchiasisMetorchis conjunctusCanada, US, Greenlandingestion of raw fish
Chinese liver flukeOpisthorchis viverrini, Opisthorchis felineus, Clonorchis sinensisbile duct1.5 million people in Russiaconsuming infected raw, slightly salted or frozen fish
Paragonimiasis, lung flukeParagonimus westermani; Paragonimus africanus; Paragonimus caliensis; Paragonimus kellicotti; Paragonimus skrjabini; Paragonimus uterobilateralislungssputum, fecesEast Asiaingestion of raw or undercooked freshwater crabs crayfishes or other crustaceans
Schistosomiasis – bilharzia, bilharziosis or snail fever Schistosoma sp.Africa, Caribbean, eastern South America, east Asia, Middle East – 200 million peopleskin exposure to water contaminated with infected freshwater snails
intestinal schistosomiasisSchistosoma mansoni and Schistosoma intercalatumintestine, liver, spleen, lungs, skin, rarely infects the brainstoolAfrica, Caribbean, South America, Asia, Middle East – 83 million peopleskin exposure to water contaminated with infected Biomphalaria freshwater snails
urinary blood flukeSchistosoma haematobiumkidney, bladder, ureters, lungs, skinurineAfrica, Middle Eastskin exposure to water contaminated with infected Bulinus sp. snails
Schistosomiasis by Schistosoma japonicumSchistosoma japonicumintestine, liver, spleen, lungs, skinstoolChina, East Asia, Philippinesskin exposure to water contaminated with infected Oncomelania sp. snails
Asian intestinal schistosomiasisSchistosoma mekongiSouth East Asiaskin exposure to water contaminated with infected Neotricula aperta – freshwater snails
EchinostomiasisEchinostoma echinatumsmall intestineFar Eastingestion of raw fish, mollusks, snails
Swimmer's itchTrichobilharzia regenti, Schistosomatidaeworldwideskin exposure to contaminated water

Roundworms

Disease causedLatin name Habitat in definite hostPrevalenceVector or intermediate hostMode of transmission
Ancylostomiasis/HookwormAncylostoma duodenale, Necator americanuslungs, small intestine, bloodstoolcommon in tropical, warm, moist climatespenetration of skin by L3 larva
AngiostrongyliasisAngiostrongylusintestinestoolingestion of infected faeces or infected slugs
AnisakiasisAnisakisallergic reactionbiopsyincidental hostingestion of raw fish, squid, cuttlefish, octopus
Roundworm – Parasitic pneumoniaAscaris sp. Ascaris lumbricoidesIntestines, liver, appendix, pancreas, lungs, Löffler's syndromestoolcommon in tropical and subtropical regions
Roundworm – BaylisascariasisBaylisascaris procyonisIntestines, liver, lungs, brain, eyerare: North Americastool from raccoons
Roundworm-lymphatic filariasisBrugia malayi, Brugia timorilymph nodesblood samplestropical regions of Asiaarthropods
Dioctophyme renalis infectionDioctophyme renalekidneys urinerareingestion of undercooked or raw freshwater fish
Guinea worm – DracunculiasisDracunculus medinensissubcutaneous tissues, muscleskin blister/ulcerSouth Sudan
Pinworm – EnterobiasisEnterobius vermicularis, Enterobius gregoriiintestines, anusstool; tape test around anuswidespread; temperate regions
GnathostomiasisGnathostoma spinigerum, Gnathostoma hispidumsubcutaneous tissues physical examinationrare – Southeast Asiaingestion of raw or undercooked meat or contaminated water
HalicephalobiasisHalicephalobus gingivalisbrainsoil-contaminated wounds
Loa loa filariasis, Calabar swellingsLoa loa filariaconnective tissue, lungs, eyeblood rain forest of West Africa – 12–13 million peopleTabanidae – horsefly, bites in the day
Mansonelliasis, filariasisMansonella streptocercasubcutaneous layer of skininsect
River blindness, onchocerciasisOnchocerca volvulusskin, eye, tissuebloodless skin snipAfrica, Yemen, Central and South America near cool, fast flowing riversSimulium/black fly, bites during the day
Strongyloidiasis – Parasitic pneumoniaStrongyloides stercoralisintestines, lungs, skin stool, bloodskin penetration
ThelaziasisThelazia californiensis, Thelazia callipaedaeyesocular examinationAsia, EuropeAmiota variegata, Phortica okadai
ToxocariasisToxocara canis, Toxocara cati, Toxascaris leoninaliver, brain, eyes blood, ocular examinationworldwide distributionpica, unwashed food contamined with Toxocara eggs, undercooked livers of chicken
TrichinosisTrichinella spiralis, Trichinella britovi, Trichinella nelsoni, Trichinella nativamuscle, periorbital region, small intestinebloodmore common in developing countries due to improved feeding practices in developed countries.ingestion of undercooked pork
WhipwormTrichuris trichiura, Trichuris vulpislarge intestine, anusstool common worldwideaccidental ingestion of eggs in dry goods such as beans, rice, and various grains or soil contaminated with human feces
Elephantiasis – Lymphatic filariasisWuchereria bancrofti''lymphatic systemthick blood smears stained with hematoxylin.tropical and subtropicalmosquito, bites at night

Other organisms

Common name of organism or diseaseLatin name Body parts affectedDiagnostic specimenPrevalenceTransmission/Vector
AcanthocephaliasisArchiacanthocephala, Moniliformis moniliformisGastrointestinal tract, peritoneum, eyeFaeces, parasite itselfworldwideingestion of intermediate hosts
Halzoun syndromeLinguatula serratanasopharynxphysical examinationMid Eastingestion of raw or undercooked lymph nodes
MyiasisOestroidea, Calliphoridae, Sarcophagidaedead or living tissue
Screwworm, CochliomyiaCochliomyia hominivorax skin and woundsvisualNorth America, Central America, North Africadirect contact with fly
Chigoe fleaTunga penetransSubcutaneous tissuephysical examinationCentral and South America, Sub-Saharan Africa
Human botflyDermatobia hominisSubcutaneous tissuephysical examinationCentral and South Americamosquitoes and biting flies

Ectoparasites

Common name of organism or diseaseLatin name Body parts affectedDiagnostic specimenPrevalenceTransmission/Vector
Head louse – PediculosisPediculus humanus capitishair folliclesvisual identification under magnificationcommon worldwidehead-to-head contact
Body louse – PediculosisPediculus humanus humanusskinvisual identification under magnification common worldwideskin-to-skin contact such as sexual activity and via sharing clothing or bedding
Crab louse –PhthiriasisPthirus pubispubic area, eyelashesvisual identification under magnificationcommon worldwideskin-to-skin contact such as sexual activity and via sharing clothing or bedding
"Chiggers" – TrombiculosisArachnida: Trombiculidaeskinvisual identification under magnification, microscopyworldwide high grass, weeds
FleaSiphonaptera: Pulicinaeskinvisual identification under magnificationworldwideenvironment
Bed bugCimicidae: Cimex lectularius and Cimex hemipterusskinvisualworldwidesharing of clothing, bedding and hitchhiking in personal possessions
TickArachnida: Ixodidae and Argasidaeskinvisualworldwidehigh grass, leaf litter, weeds
MosquitoInsecta: Dipteraskinvisualworldwidehigh grass, weeds
Demodex – DemodicosisDemodex folliculorum/brevis/caniseyebrow, eyelashes, skin, face, scalpmicroscopy of eyelash or eyebrow hair follicle, cellophane tape method, squeezing method, skin scrapingspandemic, worldwideCommensal, prolonged skin-to-skin contact
ScabiesSarcoptes scabieiskinmicroscopy of surface scrapingsworldwideskin-to-skin contact such as sexual activity and via sharing clothing or bedding
Red mite — GamasoidosisDermanyssus gallinaeskinvisual identification under magnificationworldwidenesting birds, pets, poultry farming
Northern fowl mite — GamasoidosisOrnithonyssus sylviarumskinvisual identification under magnificationworldwidenesting birds, poultry farming
Tropical fowl mite — GamasoidosisOrnithonyssus bursaskinvisual identification under magnificationworldwidenesting birds, poultry farming
Tropical rat mite — Rodent mite dermatitisOrnithonyssus bacotiskinvisual identification under magnificationworldwiderodent infestations
Spiny rat mite — Rodent mite dermatitisLaelaps echidninaskinvisual identification under magnificationworldwiderodent infestations
House mouse mite — Rodent mite dermatitisLiponyssoides sanguineusskinvisual identification under magnificationworldwiderodent infestations