| 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] | eating food contaminated with feces from an infected human or animal |
| | | | | • Developing regions: infects 40–100% of the total populations[1][2][3] | |
| 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 thru 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 |
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| Helminths (worms)[edit] | | | | | |
| Helminth organisms (also called helminths or intestinal worms) include: | | | | | |
| Tapeworms[edit] | | | | | |
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| Common name of organism or disease | Latin name (sorted) | Body parts affected | Diagnostic specimen | Prevalence | Transmission/Vector |
| Tapeworm – Tapeworm 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 |
| 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 | Mediterranean countries | 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 | Asia, Africa, South America, Southern Europe, North America. | ingestion of undercooked pork |
| 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) |
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| Flukes | | | | | |
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| 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 fluke – Fasciolosis[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) |
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| Roundworms | | | | | |
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| Disease caused | Latin name (sorted) | Habitat in definite host | Prevalence | Vector or intermediate host | 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 |
| Roundworm – Parasitic 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 worm – Dracunculiasis | Dracunculus medinensis | subcutaneous tissues, muscle | skin blister/ulcer | South Sudan (eradication ongoing) | |
| Pinworm – Enterobiasis | 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 |
| Strongyloidiasis – Parasitic 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 canis – visceral 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 |
| Elephantiasis – Lymphatic filariasis | Wuchereria bancrofti | lymphatic system | thick blood smears stained with hematoxylin. | tropical and subtropical | mosquito, bites at night |
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| 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 |
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| Common name of organism or disease | Latin name (sorted) | Body parts affected | Diagnostic specimen | Prevalence | Transmission/Vector |
| Head louse – Pediculosis | 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 louse –Phthiriasis | 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 |
| Demodex – Demodicosis | 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 mite — Gamasoidosis | 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 |
Discussion