List of parasites of humans

From WikiProjectMed
Jump to navigation Jump to search

Human parasites include various protozoa and worms. Human parasites are divided into endoparasites, which cause infection inside the body, and ectoparasites, which cause infection superficially within the skin. Below is a list of parasites of humans.


Protozoan organisms

Common name of organism or disease Latin name (sorted) Body parts affected Diagnostic specimen Prevalence Source/Transmission (Reservoir/Vector)
Granulomatous amoebic encephalitis and Acanthamoeba keratitis (eye infection) Acanthamoeba spp. eye, brain, skin culture worldwide contact lenses cleaned with contaminated tap water
Granulomatous amoebic encephalitis Balamuthia mandrillaris brain, skin culture worldwide via inhalation or skin lesion
Babesiosis Babesia B. divergens, B. bigemina, B. equi, B. microfti, B. duncani red blood cells Giemsa-stained thin blood smear New England (different species have worldwide distribution) tick bites, e.g. Ixodes scapularis
Balantidiasis Balantidium coli intestinal mucosa, may become invasive in some patients stool (diarrhea=ciliated trophozoite; solid stool=large cyst with horseshoe shaped nucleus) ingestion of cyst, zoonotic infection acquired from pigs (feces)
Blastocystosis Blastocystis spp. intestinal direct microscopy of stool (PCR, antibody)  • worldwide: one of the most common human parasites[1][2]
 • Developing regions: infects 40–100% of the total populations[1][2][3]
eating food contaminated with feces from an infected human or animal
Cryptosporidiosis Cryptosporidium spp. intestines stool widespread ingestion of oocyst (sporulated), some species are zoonotic (e.g. bovine fecal contamination)
Cyclosporiasis Cyclospora cayetanensis intestines stool United States ingestion of oocyst through contaminated food
Dientamoebiasis Dientamoeba fragilis intestines stool up to 10% in industrialized countries ingesting water or food contaminated with feces
Amoebiasis Entamoeba histolytica intestines (mainly colon, but can cause liver failure if not treated) stool (fresh diarrheic stools have amoeba, solid stool has cyst) areas with poor sanitation, high population density and tropical regions fecal-oral transmission of cyst, not amoeba
Giardiasis Giardia lamblia lumen of the small intestine stool worldwide? ingestion of water containing deer or beaver feces
Isosporiasis Isospora belli epithelial cells of small intestines stool worldwide – less common than Toxoplasma or Cryptosporidium fecal oral route – ingestion of sporulated oocyst
Leishmaniasis Leishmania spp. cutaneous, mucocutaneous, or visceral visual identification of lesion or microscopic stain with Leishman's or Giemsa's stain visceral leishmaniasis – worldwide; cutaneous leishmaniasis – Old World; mucocutaneous leishmaniasis – New World Phlebotomus, Lutzomyia – bite of several species of phlebotomine sandflies
Primary amoebic meningoencephalitis (PAM)[4][5] Naegleria fowleri brain culture unknown, but infection is rare nasal insufflation of contaminated warm fresh water, poorly chlorinated swimming pools, hot springs, soil
Malaria Plasmodium falciparum (80% of cases), Plasmodium vivax, Plasmodium ovale curtisi, Plasmodium ovale wallikeri, Plasmodium malariae, Plasmodium knowlesi red blood cells, liver blood film tropical – 250 million cases/year Anopheles mosquito
Rhinosporidiosis Rhinosporidium seeberi nose, nasopharynx biopsy India and Sri Lanka nasal mucosa came into contact with infected material through bathing in common ponds
Sarcocystosis Sarcocystis bovihominis,Sarcocystis suihominis intestine, muscle muscle biopsy widespread ingestion of uncooked/undercooked beef/pork with Sarcocystis sarcocysts
Toxoplasmosis (Acute and Latent) Toxoplasma gondii eyes, brain, heart, liver blood and PCR worldwide: one of the most common human parasites; estimated to infect between 30–50% of the global population.[6][7] 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
Trichomoniasis Trichomonas vaginalis female urogenital tract (males asymptomatic) microscopic examination of genital swab worldwide sexually transmitted infection – only trophozoite form (no cysts)
Sleeping sickness Trypanosoma brucei brain and blood microscopic examination of chancre fluid, lymph node aspirates, blood, bone marrow 50,000 to 70,000 people; only found in Africa tsetse fly, day-biting fly of the genus Glossina
Chagas disease Trypanosoma cruzi colon, esophagus, heart, nerves, muscle and blood Giemsa stain – blood Mexico, Central America, South America – 16–18 million Triatoma/Reduviidae – "kissing bug" insect vector, feeds at night

Helminths (worms)

Helminth organisms (also called helminths or intestinal worms) include:


a-c)Diphyllobothrium latum, d) PCR identification
Common name of organism or disease Latin name (sorted) Body parts affected Diagnostic specimen Prevalence Transmission/Vector
TapewormTapeworm infection Cestoda, Taenia multiceps intestine stool rare worldwide
Diphyllobothriasis – tapeworm Diphyllobothrium latum intestines, blood stool (microscope) Europe, Japan, Uganda, Peru, Chile ingestion of raw fresh water fish
Diphyllobothriasis – tapeworm Diphyllobothrium pacificum intestines stool (microscope) Peru ingestion of raw saltwater fish
Echinococcosis – tapeworm Echinococcus granulosus, Echinococcus multilocularis, E. vogeli, E. oligarthrus liver, lungs, kidney, spleen imaging of hydatid cysts in the liver, lungs, kidney and spleen Worldwide in grazing areas as intermediate host, ingestion of material contaminated by feces from a carnivore; as definite host, ingestion of uncooked meat (offal) from a herbivore
Hymenolepiasis[8] Hymenolepis nana, Hymenolepis diminuta ingestion of material contaminated by flour beetles, mealworms, cockroaches
Beef tapeworm Taenia saginata Intestines stool worldwide distribution ingestion of undercooked beef
Cysticercosis-Pork tapeworm Taenia solium Brain, muscle, Eye (Cysts in conjuntiva/anterior chamber/sub-retinal space) stool, blood, imaging of cysts in the brain or any soft tissue Asia, Africa, South America, Southern Europe, North America. as definite host: ingestion of undercooked pork; as intermediate host, ingestion of material contaminated by human feces from a person carrying the adult form
Bertielliasis Bertiella mucronata, Bertiella studeri Intestines stool rare contact with non-human primates
Sparganosis Spirometra erinaceieuropaei ingestion of material contaminated with infected dog or cat feces (humans: dead-end host)


Common name of organism or disease Latin name (sorted) Body parts affected Diagnostic specimen Prevalence Transmission/Vector
Clonorchiasis Clonorchis sinensis; Clonorchis viverrini gall bladder ducts and inflammation of liver East Asia ingestion of under prepared freshwater fish
Lancet liver fluke Dicrocoelium dendriticum gall bladder rare ingestion of ants
Liver flukeFasciolosis[9] Fasciola hepatica, Fasciola gigantica liver, gall bladder stool Fasciola hepatica in Europe, Africa, Australia, the Americas and Oceania; Fasciola gigantica only in Africa and Asia, 2.4 million people infected by both species freshwater snails
Fasciolopsiasis – intestinal fluke[10] Fasciolopsis buski intestines stool or vomitus (microscope) East Asia – 10 million people ingestion of infested water plants or water (intermediate host:amphibic snails)
Metagonimiasis – intestinal fluke Metagonimus yokogawai stool Siberia, Manchuria, Balkan states, Israel, Spain ingestion of undercooked or salted fish
Metorchiasis Metorchis conjunctus Canada, US, Greenland ingestion of raw fish
Chinese liver fluke Opisthorchis viverrini, Opisthorchis felineus, Clonorchis sinensis bile duct 1.5 million people in Russia consuming infected raw, slightly salted or frozen fish
Paragonimiasis, lung fluke Paragonimus westermani; Paragonimus africanus; Paragonimus caliensis; Paragonimus kellicotti; Paragonimus skrjabini; Paragonimus uterobilateralis lungs sputum, feces East Asia ingestion of raw or undercooked freshwater crabs crayfishes or other crustaceans
Schistosomiasis – bilharzia, bilharziosis or snail fever (all types) Schistosoma sp. Africa, Caribbean, eastern South America, east Asia, Middle East – 200 million people skin exposure to water contaminated with infected freshwater snails
intestinal schistosomiasis Schistosoma mansoni and Schistosoma intercalatum intestine, liver, spleen, lungs, skin, rarely infects the brain stool Africa, Caribbean, South America, Asia, Middle East – 83 million people skin exposure to water contaminated with infected Biomphalaria freshwater snails
urinary blood fluke Schistosoma haematobium kidney, bladder, ureters, lungs, skin urine Africa, Middle East skin exposure to water contaminated with infected Bulinus sp. snails
Schistosomiasis by Schistosoma japonicum Schistosoma japonicum intestine, liver, spleen, lungs, skin stool China, East Asia, Philippines skin exposure to water contaminated with infected Oncomelania sp. snails
Asian intestinal schistosomiasis Schistosoma mekongi South East Asia skin exposure to water contaminated with infected Neotricula aperta – freshwater snails
Echinostomiasis Echinostoma echinatum small intestine Far East ingestion of raw fish, mollusks, snails
Swimmer's itch Trichobilharzia regenti, Schistosomatidae worldwide skin exposure to contaminated water (snails and vertebrates)


Disease caused Latin name (sorted) Habitat in definite host Diagnostic Sample Prevalence Mode of transmission
Ancylostomiasis/Hookworm Ancylostoma duodenale, Necator americanus lungs, small intestine, blood stool common in tropical, warm, moist climates penetration of skin by L3 larva
Angiostrongyliasis Angiostrongylus intestine stool ingestion of infected faeces or infected slugs
Anisakiasis[11] Anisakis allergic reaction biopsy incidental host ingestion of raw fish, squid, cuttlefish, octopus
RoundwormParasitic pneumonia Ascaris sp. Ascaris lumbricoides Intestines, liver, appendix, pancreas, lungs, Löffler's syndrome stool common in tropical and subtropical regions
Roundworm – Baylisascariasis Baylisascaris procyonis Intestines, liver, lungs, brain, eye rare: North America stool from raccoons
Roundworm-lymphatic filariasis Brugia malayi, Brugia timori lymph nodes blood samples tropical regions of Asia arthropods
Dioctophyme renalis infection Dioctophyme renale kidneys (typically the right) urine rare ingestion of undercooked or raw freshwater fish
Guinea wormDracunculiasis Dracunculus medinensis subcutaneous tissues, muscle skin blister/ulcer South Sudan (eradication ongoing)
PinwormEnterobiasis Enterobius vermicularis, Enterobius gregorii intestines, anus stool; tape test around anus widespread; temperate regions
Gnathostomiasis[12] Gnathostoma spinigerum, Gnathostoma hispidum subcutaneous tissues (under the skin) physical examination rare – Southeast Asia ingestion of raw or undercooked meat (e.g., freshwater fish, chicken, snails, frogs, pigs) or contaminated water
Halicephalobiasis Halicephalobus gingivalis brain soil-contaminated wounds
Loa loa filariasis, Calabar swellings Loa loa filaria connective tissue, lungs, eye blood (Giemsa, haematoxylin, eosin stain) rain forest of West Africa – 12–13 million people Tabanidae – horsefly, bites in the day
Mansonelliasis, filariasis Mansonella streptocerca subcutaneous layer of skin insect
River blindness, onchocerciasis Onchocerca volvulus skin, eye, tissue bloodless skin snip Africa, Yemen, Central and South America near cool, fast flowing rivers Simulium/black fly, bites during the day
StrongyloidiasisParasitic pneumonia Strongyloides stercoralis intestines, lungs, skin (Larva currens) stool, blood skin penetration
Thelaziasis Thelazia californiensis, Thelazia callipaeda eyes ocular examination Asia, Europe Amiota (Phortica) variegata, Phortica okadai
Toxocariasis Toxocara canis, Toxocara cati, Toxascaris leonina liver, brain, eyes (Toxocara canisvisceral larva migrans, ocular larva migrans) blood, ocular examination worldwide distribution pica, unwashed food contaminated with Toxocara eggs, undercooked livers of chicken
Trichinosis Trichinella spiralis, Trichinella britovi, Trichinella nelsoni, Trichinella nativa muscle, periorbital region, small intestine blood more common in developing countries due to improved feeding practices in developed countries. ingestion of undercooked pork
Whipworm Trichuris trichiura, Trichuris vulpis large intestine, anus stool (eggs) common worldwide accidental ingestion of eggs in dry goods such as beans, rice, and various grains or soil contaminated with human feces
ElephantiasisLymphatic filariasis Wuchereria bancrofti lymphatic system thick blood smears stained with hematoxylin. tropical and subtropical mosquito, bites at night

Other organisms

Common name of organism or disease Latin name (sorted) Body parts affected Diagnostic specimen Prevalence Transmission/Vector
Acanthocephaliasis Archiacanthocephala, Moniliformis moniliformis Gastrointestinal tract, peritoneum, eye Faeces, parasite itself worldwide ingestion of intermediate hosts
Halzoun syndrome Linguatula serrata nasopharynx physical examination Mid East ingestion of raw or undercooked lymph nodes (e.g., meat from infected camels and buffaloes)
Myiasis Oestroidea, Calliphoridae, Sarcophagidae dead or living tissue
Screwworm, Cochliomyia Cochliomyia hominivorax (family Calliphoridae) skin and wounds visual North America (eradicated), Central America, North Africa direct contact with fly
Chigoe flea Tunga penetrans Subcutaneous tissue physical examination Central and South America, Sub-Saharan Africa
Human botfly Dermatobia hominis Subcutaneous tissue physical examination Central and South America mosquitoes and biting flies


Common name of organism or disease Latin name (sorted) Body parts affected Diagnostic specimen Prevalence Transmission/Vector
Head lousePediculosis Pediculus humanus capitis hair follicles visual identification under magnification common worldwide head-to-head contact
Body louse – Pediculosis Pediculus humanus humanus skin visual identification under magnification (Vagabond's disease) common worldwide skin-to-skin contact such as sexual activity and via sharing clothing or bedding
Crab lousePhthiriasis Pthirus pubis pubic area, eyelashes visual identification under magnification common worldwide skin-to-skin contact such as sexual activity and via sharing clothing or bedding
"Chiggers" (Trombiculidae) – Trombiculosis Arachnida: Trombiculidae skin visual identification under magnification, microscopy worldwide (mesic habitats) high grass, weeds
Flea Siphonaptera: Pulicinae skin visual identification under magnification worldwide environment
Bed bug Cimicidae: Cimex lectularius and Cimex hemipterus skin visual worldwide sharing of clothing, bedding and hitchhiking in personal possessions
Tick Arachnida: Ixodidae and Argasidae skin visual worldwide high grass, leaf litter, weeds
Mosquito Insecta: Diptera skin visual worldwide high grass, weeds
DemodexDemodicosis Demodex folliculorum/brevis/canis eyebrow, eyelashes, skin, face, scalp microscopy of eyelash or eyebrow hair follicle, cellophane tape method (CTP), squeezing method, skin scrapings pandemic, worldwide Commensal, prolonged skin-to-skin contact
Scabies Sarcoptes scabiei skin microscopy of surface scrapings worldwide skin-to-skin contact such as sexual activity and via sharing clothing or bedding
Red miteGamasoidosis Dermanyssus gallinae skin visual identification under magnification worldwide nesting birds, pets, poultry farming
Northern fowl mite — Gamasoidosis Ornithonyssus sylviarum skin visual identification under magnification worldwide nesting birds, poultry farming
Tropical fowl mite — Gamasoidosis Ornithonyssus bursa skin visual identification under magnification worldwide nesting birds, poultry farming
Tropical rat mite — Rodent mite dermatitis Ornithonyssus bacoti skin visual identification under magnification worldwide rodent infestations
Spiny rat mite — Rodent mite dermatitis Laelaps echidnina skin visual identification under magnification worldwide rodent infestations
House mouse mite — Rodent mite dermatitis Liponyssoides sanguineus skin visual identification under magnification worldwide rodent infestations


  1. 1.0 1.1 Boorom KF, Smith H, Nimri L, Viscogliosi E, Spanakos G, Parkar U, Li LH, Zhou XN, Ok UZ, Leelayoova S, Jones MS (2008). "Oh my aching gut: irritable bowel syndrome, Blastocystis, and asymptomatic infection". Parasit Vectors. 1 (1): 40. doi:10.1186/1756-3305-1-40. PMC 2627840. PMID 18937874. Blastocystis is now by far the most prevalent mono-infection in symptomatic patients in the United States [14] and was found 28.5 times more often than Giardia lamblia as a mono-infection in symptomatic patients in a 2000 study .
  2. 2.0 2.1 Roberts T, Stark D, Harkness J, Ellis J (May 2014). "Update on the pathogenic potential and treatment options for Blastocystis sp". Gut Pathog. 6: 17. doi:10.1186/1757-4749-6-17. PMC 4039988. PMID 24883113. Blastocystis is one of the most common intestinal protists of humans. ... A recent study showed that 100% of people from low socio-economic villages in Senegal were infected with Blastocystis sp. suggesting that transmission was increased due to poor hygiene sanitation, close contact with domestic animals and livestock, and water supply directly from well and river [10]. ...
  3. El Safadi D, Gaayeb L, Meloni D, Cian A, Poirier P, Wawrzyniak I, Delbac F, Dabboussi F, Delhaes L, Seck M, Hamze M, Riveau G, Viscogliosi E (March 2014). "Children of Senegal River Basin show the highest prevalence of Blastocystis sp. ever observed worldwide". BMC Infect. Dis. 14: 164. doi:10.1186/1471-2334-14-164. PMC 3987649. PMID 24666632.
  4. Cogo PE, Scaglia M, Gatti S, Rossetti F, Alaggio R, Laverda AM, et al. Fatal Naegleria fowleri Meningoencephalitis, Italy Emerging Infectious Diseases [serial on the Internet]. 2004 Oct; accessed Jan 2009
  5. Bennett, Nicholas John State University of New York Upstate Medical University Domachowske, Joseph; Khan, Asad A Louisiana State University Health Science Center; King, John W; Cross, J Thomas Naegleria Archived 2009-09-19 at the Wayback Machine eMedicine; accessed Jan 2009
  6. Flegr J, Prandota J, Sovičková M, Israili ZH (March 2014). "Toxoplasmosis—a global threat. Correlation of latent toxoplasmosis with specific disease burden in a set of 88 countries". PLOS ONE. 9 (3): e90203. Bibcode:2014PLoSO...990203F. doi:10.1371/journal.pone.0090203. PMC 3963851. PMID 24662942. Toxoplasmosis is becoming a global health hazard as it infects 30-50% of the world human population. Clinically, the life-long presence of the parasite in tissues of a majority of infected individuals is usually considered asymptomatic. However, a number of studies show that this 'asymptomatic infection' may also lead to development of other human pathologies. ... The seroprevalence of toxoplasmosis correlated with various disease burden. Statistical associations does not necessarily mean causality. The precautionary principle suggests however that possible role of toxoplasmosis as a triggering factor responsible for development of several clinical entities deserves much more attention and financial support both in everyday medical practice and future clinical research.
  7. Pappas, G; Roussos, N; Falagas, ME (October 2009). "Toxoplasmosis snapshots: global status of Toxoplasma gondii seroprevalence and implications for pregnancy and congenital toxoplasmosis". International Journal for Parasitology. 39 (12): 1385–94. doi:10.1016/j.ijpara.2009.04.003. PMID 19433092.
  8. Tolan, Robert W Jr Hymenolepiasis Archived 2009-11-05 at the Wayback Machine eMedicine; updated Feb 2008
  9. Yılmaz, Hasan; Gödekmerdan, Ahmet (2004), "Human fasciolosis in Van province, Turkey", Acta Tropica, 92 (2): 161–2, doi:10.1016/j.actatropica.2004.04.009, PMID 15350869
  10. Centers for Disease Control and Prevention Fasciolopsiasis Archived 2009-10-09 at the Wayback Machine
  11. "Anisakiasis". Archived from the original on 2009-10-09. Retrieved 2009-01-01.
  12. Tolan, Robert W Gnathostomiasis Archived 2009-03-03 at the Wayback Machine eMedicine, updated Feb 2008