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 |
Helminth organisms (also called helminths or intestinal worms) include:
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 |
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 conjunctiva/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 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) |
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 |
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 |
Ophidascaris robertsi infection | Ophidascaris robertsi | brain | newly discovered infection [12] [13] | Single reported case was likely due to ingestion of gathered wild plants, contaminated with feces from pythons | |
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 [14] | 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 |
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 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 | clothing, bedding, 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 |
Trichuris trichiura, Trichocephalus trichiuris or whipworm, is a parasitic roundworm that causes trichuriasis when it infects a human large intestine. It is commonly known as the whipworm which refers to the shape of the worm; it looks like a whip with wider "handles" at the posterior end.
Trichuriasis, also known as whipworm infection, is an infection by the parasitic worm Trichuris trichiura (whipworm). If infection is only with a few worms, there are often no symptoms. In those who are infected with many worms, there may be abdominal pain, fatigue and diarrhea. The diarrhea sometimes contains blood. Infections in children may cause poor intellectual and physical development. Low red blood cell levels may occur due to loss of blood.
Toxoplasmosis is a parasitic disease caused by Toxoplasma gondii, an apicomplexan. Infections with toxoplasmosis are associated with a variety of neuropsychiatric and behavioral conditions. Occasionally, people may have a few weeks or months of mild, flu-like illness such as muscle aches and tender lymph nodes. In a small number of people, eye problems may develop. In those with a weak immune system, severe symptoms such as seizures and poor coordination may occur. If a woman becomes infected during pregnancy, a condition known as congenital toxoplasmosis may affect the child.
Toxoplasma gondii is a parasitic protozoan that causes toxoplasmosis. Found worldwide, T. gondii is capable of infecting virtually all warm-blooded animals, but felids are the only known definitive hosts in which the parasite may undergo sexual reproduction.
An intestinal parasite infection is a condition in which a parasite infects the gastro-intestinal tract of humans and other animals. Such parasites can live anywhere in the body, but most prefer the intestinal wall.
Ascariasis is a disease caused by the parasitic roundworm Ascaris lumbricoides. Infections have no symptoms in more than 85% of cases, especially if the number of worms is small. Symptoms increase with the number of worms present and may include shortness of breath and fever in the beginning of the disease. These may be followed by symptoms of abdominal swelling, abdominal pain, and diarrhea. Children are most commonly affected, and in this age group the infection may also cause poor weight gain, malnutrition, and learning problems.
Helminthiasis, also known as worm infection, is any macroparasitic disease of humans and other animals in which a part of the body is infected with parasitic worms, known as helminths. There are numerous species of these parasites, which are broadly classified into tapeworms, flukes, and roundworms. They often live in the gastrointestinal tract of their hosts, but they may also burrow into other organs, where they induce physiological damage.
Hookworm infection is an infection by a type of intestinal parasite known as a hookworm. Initially, itching and a rash may occur at the site of infection. Those only affected by a few worms may show no symptoms. Those infected by many worms may experience abdominal pain, diarrhea, weight loss, and tiredness. The mental and physical development of children may be affected. Anemia may result.
Strongyloidiasis is a human parasitic disease caused by the nematode called Strongyloides stercoralis, or sometimes the closely related S. fülleborni. These helminths belong to a group of nematodes called roundworms. These intestinal worms can cause a number of symptoms in people, principally skin symptoms, abdominal pain, diarrhea and weight loss, but also many other specific and vague symptoms in disseminated disease, and severe life-threatening conditions through hyperinfection. In some people, particularly those who require corticosteroids or other immunosuppressive medication, Strongyloides can cause a hyperinfection syndrome that can lead to death if untreated. The diagnosis is made by blood and stool tests. The medication ivermectin is widely used to treat strongyloidiasis.
Taenia saginata, commonly known as the beef tapeworm, is a zoonotic tapeworm belonging to the order Cyclophyllidea and genus Taenia. It is an intestinal parasite in humans causing taeniasis and cysticercosis in cattle. Cattle are the intermediate hosts, where larval development occurs, while humans are definitive hosts harbouring the adult worms. It is found globally and most prevalently where cattle are raised and beef is consumed. It is relatively common in Africa, Europe, Southeast Asia, South Asia, and Latin America. Humans are generally infected as a result of eating raw or undercooked beef which contains the infective larvae, called cysticerci. As hermaphrodites, each body segment called proglottid has complete sets of both male and female reproductive systems. Thus, reproduction is by self-fertilisation. From humans, embryonated eggs, called oncospheres, are released with faeces and are transmitted to cattle through contaminated fodder. Oncospheres develop inside muscle, liver, and lungs of cattle into infective cysticerci.
Ascaris is a nematode genus of parasitic worms known as the "small intestinal roundworms", which is a type of parasitic worm. One species, Ascaris lumbricoides, affects humans and causes the disease ascariasis. Another species, Ascaris suum, typically infects pigs. Other ascarid genera infect other animals, such as Parascaris equorum, the equine roundworm, and Toxocara and Toxascaris, which infect dogs and cats.
Parasitic worms, also known as helminths, are large macroparasites; adults can generally be seen with the naked eye. Many are intestinal worms that are soil-transmitted and infect the gastrointestinal tract. Other parasitic worms such as schistosomes reside in blood vessels.
Helminthic therapy, an experimental type of immunotherapy, is the treatment of autoimmune diseases and immune disorders by means of deliberate infestation with a helminth or with the eggs of a helminth. Helminths are parasitic worms such as hookworms, whipworms, and threadworms that have evolved to live within a host organism on which they rely for nutrients. These worms are members of two phyla: nematodes, which are primarily used in human helminthic therapy, and flat worms (trematodes).
A subclinical infection—sometimes called a preinfection or inapparent infection—is an infection by a pathogen that causes few or no signs or symptoms of infection in the host. Subclinical infections can occur in both humans and animals. Depending on the pathogen, which can be a virus or intestinal parasite, the host may be infectious and able to transmit the pathogen without ever developing symptoms; such a host is called an asymptomatic carrier. Many pathogens, including HIV, typhoid fever, and coronaviruses such as COVID-19 spread in their host populations through subclinical infection.
Antiparasitics are a class of medications which are indicated for the treatment of parasitic diseases, such as those caused by helminths, amoeba, ectoparasites, parasitic fungi, and protozoa, among others. Antiparasitics target the parasitic agents of the infections by destroying them or inhibiting their growth; they are usually effective against a limited number of parasites within a particular class. Antiparasitics are one of the antimicrobial drugs which include antibiotics that target bacteria, and antifungals that target fungi. They may be administered orally, intravenously or topically. Overuse or misuse of antiparasitics can lead to the development of antimicrobial resistance.
Nitazoxanide, sold under the brand name Alinia among others, is a broad-spectrum antiparasitic and broad-spectrum antiviral medication that is used in medicine for the treatment of various helminthic, protozoal, and viral infections. It is indicated for the treatment of infection by Cryptosporidium parvum and Giardia lamblia in immunocompetent individuals and has been repurposed for the treatment of influenza. Nitazoxanide has also been shown to have in vitro antiparasitic activity and clinical treatment efficacy for infections caused by other protozoa and helminths; evidence as of 2014 suggested that it possesses efficacy in treating a number of viral infections as well.
Blastocystis is a genus of single-celled parasites belonging to the Stramenopiles that includes algae, diatoms, and water molds. There are several species, living in the gastrointestinal tracts of species as diverse as humans, farm animals, birds, rodents, reptiles, amphibians, fish, and cockroaches. Blastocystis has low host specificity, and many different species of Blastocystis can infect humans, and by current convention, any of these species would be identified as Blastocystis hominis.
The discovery of disease-causing pathogens is an important activity in the field of medical science. Many viruses, bacteria, protozoa, fungi, helminths, and prions are identified as a confirmed or potential pathogen. In the United States, a Centers for Disease Control and Prevention program, begun in 1995, identified over a hundred patients with life-threatening illnesses that were considered to be of an infectious cause but that could not be linked to a known pathogen. The association of pathogens with disease can be a complex and controversial process, in some cases requiring decades or even centuries to achieve.
Blastocystosis refers to a medical condition caused by infection with Blastocystis. Blastocystis is a protozoal, single-celled parasite that inhabits the gastrointestinal tracts of humans and other animals. Many different types of Blastocystis exist, and they can infect humans, farm animals, birds, rodents, amphibians, reptiles, fish, and even cockroaches. Blastocystosis has been found to be a possible risk factor for development of irritable bowel syndrome.
Soil-transmitted helminthiasis is a type of worm infection (helminthiasis) caused by different species of roundworms. It is caused specifically by those worms which are transmitted through soil contaminated with faecal matter and are therefore called soil-transmitted helminths. Three types of soil-transmitted helminthiasis can be distinguished: ascariasis, hookworm infection and whipworm infection. These three types of infection are therefore caused by the large roundworm A. lumbricoides, the hookworms Necator americanus or Ancylostoma duodenale and by the whipworm Trichuris trichiura.
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 [14].Figure 4: Prevalence of IBS and Blastocystosis by country
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]. ...Table 2: Summary of treatments and efficacy for Blastocystis infection
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.