List of parasites of humans

Last updated

Endoparasites

Protozoan organisms

Common name of organism or diseaseLatin name (sorted)Body parts affectedDiagnostic specimenPrevalenceSource/Transmission (Reservoir/Vector)
Granulomatous amoebic encephalitis and Acanthamoeba keratitis (eye infection) Acanthamoeba spp.eye, brain, skincultureworldwide contact lenses cleaned with contaminated tap water
Granulomatous amoebic encephalitis Balamuthia mandrillaris brain, skincultureworldwidevia inhalation or skin lesion
Babesiosis Babesia B. divergens, B. bigemina, B. equi, B. microfti, B. duncanired 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 patientsstool (diarrhea=ciliated trophozoite; solid stool=large cyst with horseshoe shaped nucleus)ingestion of cyst, zoonotic infection acquired from pigs (feces)
Blastocystosis Blastocystis spp.intestinaldirect 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.intestinesstoolwidespreadingestion of oocyst (sporulated), some species are zoonotic (e.g. bovine fecal contamination)
Cyclosporiasis Cyclospora cayetanensis intestinesstoolUnited Statesingestion of oocyst through contaminated food
Dientamoebiasis Dientamoeba fragilis intestinesstoolup to 10% in industrialized countriesingesting 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 regionsfecal-oral transmission of cyst, not amoeba
Giardiasis Giardia lamblia lumen of the small intestine stoolworldwide?ingestion of water containing deer or beaver feces
Isosporiasis Isospora belli epithelial cells of small intestines stoolworldwide – less common than Toxoplasma or Cryptosporidiumfecal 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 braincultureunknown, but infection is rarenasal 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 biopsyIndia and Sri Lanka nasal mucosa came into contact with infected material through bathing in common ponds
Sarcocystosis Sarcocystis bovihominis , Sarcocystis suihominis intestine, muscle muscle biopsywidespreadingestion of uncooked/undercooked beef/pork with Sarcocystis sarcocysts
Toxoplasmosis (Acute and Latent) Toxoplasma gondii eyes, brain, heart, liverblood 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 swabworldwidesexually transmitted infection – only trophozoite form (no cysts)
Sleeping sickness Trypanosoma brucei brain and bloodmicroscopic examination of chancre fluid, lymph node aspirates, blood, bone marrow50,000 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:

Contents

Tapeworms

Common name of organism or diseaseLatin name (sorted)Body parts affectedDiagnostic specimenPrevalenceTransmission/Vector
TapewormTapeworm infection Cestoda , Taenia multiceps intestinestoolrare worldwide
Diphyllobothriasis – tapeworm Diphyllobothrium latum intestines, bloodstool (microscope)Europe, Japan, Uganda, Peru, Chileingestion of raw fresh water fish
Diphyllobothriasis – tapeworm Diphyllobothrium pacificum intestinesstool (microscope)Peruingestion of raw saltwater fish
Echinococcosis – tapeworm Echinococcus granulosus , Echinococcus multilocularis , E. vogeli, E. oligarthrusliver, lungs, kidney, spleenimaging of hydatid cysts in the liver, lungs, kidney and spleenWorldwide in grazing areasas 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 Intestinesstoolworldwide distributioningestion 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 tissueAsia, 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 Intestinesstoolrarecontact with non-human primates
Sparganosis Spirometra erinaceieuropaei ingestion of material contaminated with infected dog or cat feces (humans: dead-end host)

Flukes

Common name of organism or diseaseLatin name (sorted)Body parts affectedDiagnostic specimenPrevalenceTransmission/Vector
Clonorchiasis Clonorchis sinensis ; Clonorchis viverrinigall bladder ducts and inflammation of liverEast Asiaingestion of under prepared freshwater fish
Lancet liver fluke Dicrocoelium dendriticum gall bladderrareingestion of ants
Liver flukeFasciolosis [9] Fasciola hepatica , Fasciola gigantica liver, 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 fluke [10] Fasciolopsis buski intestinesstool or vomitus (microscope)East Asia – 10 million peopleingestion of infested water plants or water (intermediate host:amphibic snails)
Metagonimiasis – intestinal flukeMetagonimus yokogawaistoolSiberia, Manchuria, Balkan states, Israel, Spainingestion of undercooked or salted fish
Metorchiasis Metorchis conjunctus Canada, US, Greenlandingestion of raw fish
Chinese liver fluke Opisthorchis viverrini , Opisthorchis felineus , Clonorchis sinensis bile duct 1.5 million people in Russiaconsuming infected raw, slightly salted or frozen fish
Paragonimiasis, lung fluke Paragonimus 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 (all types) Schistosoma sp.Africa, Caribbean, eastern South America, east Asia, Middle East – 200 million peopleskin exposure to water contaminated with infected freshwater snails
intestinal schistosomiasis Schistosoma mansoni and Schistosoma intercalatum intestine, 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 fluke Schistosoma haematobium kidney, bladder, ureters, lungs, skinurineAfrica, Middle Eastskin exposure to water contaminated with infected Bulinus sp. snails
Schistosomiasis by Schistosoma japonicum Schistosoma japonicum intestine, liver, spleen, lungs, skinstoolChina, East Asia, Philippinesskin exposure to water contaminated with infected Oncomelania sp. snails
Asian intestinal schistosomiasis Schistosoma mekongi South East Asiaskin exposure to water contaminated with infected Neotricula aperta – freshwater snails
Echinostomiasis Echinostoma echinatum small intestineFar Eastingestion of raw fish, mollusks, snails
Swimmer's itch Trichobilharzia regenti , Schistosomatidae worldwideskin exposure to contaminated water (snails and vertebrates)

Roundworms

Disease causedLatin name (sorted)Habitat in definite hostDiagnostic SamplePrevalenceMode of transmission
Ancylostomiasis/Hookworm Ancylostoma duodenale , Necator americanus lungs, small intestine, bloodstoolcommon in tropical, warm, moist climatespenetration of skin by L3 larva
Angiostrongyliasis Angiostrongylus intestinestoolingestion of infected faeces or infected slugs
Anisakiasis [11] Anisakis allergic reactionbiopsyincidental hostingestion of raw fish, squid, cuttlefish, octopus
RoundwormParasitic pneumonia Ascaris sp. Ascaris lumbricoides Intestines, liver, appendix, pancreas, lungs, Löffler's syndrome stoolcommon in tropical and subtropical regions
Roundworm – Baylisascariasis Baylisascaris procyonis Intestines, liver, lungs, brain, eyerare: North Americastool from raccoons
Roundworm-lymphatic filariasis Brugia malayi , Brugia timori lymph nodesblood samplestropical regions of Asia arthropods
Dioctophyme renalis infection Dioctophyme renale kidneys (typically the right)urinerareingestion of undercooked or raw freshwater fish
Ophidascaris robertsi infection Ophidascaris robertsi brainnewly discovered infection [12] [13] Single reported case was likely due to ingestion of gathered wild plants, contaminated with feces from pythons
Guinea wormDracunculiasis Dracunculus medinensis subcutaneous tissues, muscleskin blister/ulcerSouth Sudan (eradication ongoing)
PinwormEnterobiasis Enterobius vermicularis , Enterobius gregorii intestines, anusstool; tape test around anus widespread; temperate regions
Gnathostomiasis [14] Gnathostoma spinigerum , Gnathostoma hispidum subcutaneous tissues (under the skin)physical examinationrare – Southeast Asiaingestion of raw or undercooked meat (e.g., freshwater fish, chicken, snails, frogs, pigs) or contaminated water
Halicephalobiasis Halicephalobus gingivalis brainsoil-contaminated wounds
Loa loa filariasis, Calabar swellings Loa loa filaria connective tissue, lungs, eyeblood (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 skininsect
River blindness, onchocerciasis Onchocerca volvulus skin, eye, tissuebloodless skin snipAfrica, 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, bloodskin penetration
Thelaziasis Thelazia californiensis , Thelazia callipaeda eyesocular 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 examinationworldwide 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 intestinebloodmore common in developing countries due to improved feeding practices in developed countries.ingestion of undercooked pork
Whipworm Trichuris trichiura , Trichuris vulpislarge intestine, anusstool (eggs)common worldwideaccidental ingestion of eggs in dry goods such as beans, rice, and various grains or soil contaminated with human feces
ElephantiasisLymphatic filariasis Wuchereria bancrofti lymphatic systemthick blood smears stained with hematoxylin.tropical and subtropicalmosquito, bites at night

Other organisms

Common name of organism or diseaseLatin name (sorted)Body parts affectedDiagnostic specimenPrevalenceTransmission/Vector
Acanthocephaliasis Archiacanthocephala, Moniliformis moniliformis Gastrointestinal tract, peritoneum, eyeFaeces, parasite itselfworldwideingestion of intermediate hosts
Halzoun syndrome Linguatula serrata nasopharynx physical examinationMid Eastingestion 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 woundsvisualNorth America (eradicated), Central America, North Africadirect contact with fly
Chigoe flea Tunga penetrans Subcutaneous tissue physical examinationCentral and South America, Sub-Saharan Africa
Human botfly Dermatobia hominis Subcutaneous tissue physical examinationCentral and South Americamosquitoes and biting flies

Ectoparasites

Common name of organism or diseaseLatin name (sorted)Body parts affectedDiagnostic specimenPrevalenceTransmission/Vector
Head lousePediculosis Pediculus humanus capitishair folliclesvisual identification under magnificationcommon worldwidehead-to-head contact
Body louse – PediculosisPediculus humanus humanusskinvisual identification under magnification (Vagabond's disease)common worldwideskin-to-skin contact such as sexual activity and via sharing clothing or bedding
Crab lousePhthiriasis Pthirus pubispubic area, eyelashesvisual identification under magnificationcommon worldwideskin-to-skin contact such as sexual activity and via sharing clothing or bedding
"Chiggers" (Trombiculidae) – Trombiculosis Arachnida: Trombiculidae skinvisual identification under magnification, microscopyworldwide (mesic habitats)high grass, weeds
Flea Siphonaptera: Pulicinae skinvisual identification under magnificationworldwideenvironment
Bed bug Cimicidae: Cimex lectularius and Cimex hemipterus skinvisualworldwideclothing, bedding, personal possessions
Tick Arachnida: Ixodidae and Argasidae skinvisualworldwidehigh grass, leaf litter, weeds
Mosquito Insecta: Diptera skinvisualworldwidehigh grass, weeds
DemodexDemodicosis Demodex folliculorum/brevis/caniseyebrow, eyelashes, skin, face, scalpmicroscopy of eyelash or eyebrow hair follicle, cellophane tape method (CTP), squeezing method, skin scrapingspandemic, worldwideCommensal, prolonged skin-to-skin contact
Scabies Sarcoptes scabieiskinmicroscopy of surface scrapingsworldwideskin-to-skin contact such as sexual activity and via sharing clothing or bedding
Red miteGamasoidosis Dermanyssus 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 dermatitis Ornithonyssus bacoti skinvisual identification under magnificationworldwiderodent infestations
Spiny rat mite — Rodent mite dermatitis Laelaps echidnina skinvisual identification under magnificationworldwiderodent infestations
House mouse mite — Rodent mite dermatitis Liponyssoides sanguineus skinvisual identification under magnificationworldwiderodent infestations

Related Research Articles

<span class="mw-page-title-main">Trichuriasis</span> Infection by Trichuris trichiura (whipworm)

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.

<span class="mw-page-title-main">Toxoplasmosis</span> Protozoan parasitic disease

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.

<i>Toxoplasma gondii</i> Type of protozoan parasite

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.

<span class="mw-page-title-main">Intestinal parasite infection</span> Condition in which a parasite infects the gastro-intestinal tract of humans and other animals

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.

<span class="mw-page-title-main">Ascariasis</span> Disease caused by the parasitic roundworm Ascaris lumbricoides

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.

<span class="mw-page-title-main">Helminthiasis</span> Any macroparasitic disease caused by helminths

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.

<span class="mw-page-title-main">Hookworm infection</span> Disease caused by intestinal parasites

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.

<span class="mw-page-title-main">Strongyloidiasis</span> Medical condition

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.

<i>Taenia saginata</i> Species of flatworm

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.

<i>Ascaris</i> Genus of roundworms

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.

<span class="mw-page-title-main">Parasitic worm</span> Large type of parasitic organism

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.

<span class="mw-page-title-main">Helminthic therapy</span> Deliberate infestation with parasitic worms

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).

<span class="mw-page-title-main">Subclinical infection</span> Nearly or completely asymptomatic infection

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.

<span class="mw-page-title-main">Nitazoxanide</span> Broad-spectrum antiparasitic and antiviral medication

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.

<i>Blastocystis</i> Genus of single-celled organisms

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.

<span class="mw-page-title-main">Blastocystosis</span> Medical condition

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.

The effects of parasitic worms, or helminths, on the immune system is a recently emerging topic of study among immunologists and other biologists. Experiments have involved a wide range of parasites, diseases, and hosts. The effects on humans have been of special interest. The tendency of many parasitic worms to pacify the host's immune response allows them to mollify some diseases, while worsening others.

<span class="mw-page-title-main">Soil-transmitted helminthiasis</span> Roundworm infection contracted from contaminated soil

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.

References

  1. 1 2 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 [14]. Figure 4: Prevalence of IBS and Blastocystosis by country
  2. 1 2 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]. ... Table 2: Summary of treatments and efficacy for Blastocystis infection
  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 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. Harbir Singh Arora (21 December 2020). "Hymenolepiasis". Medscape.
  9. Yılmaz H, Gödekmerdan A (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. Davey M (2023-08-28). "'Oh my god': live worm found in Australian woman's brain in world-first discovery". The Guardian. ISSN   0261-3077 . Retrieved 2023-10-18.
  13. "Worm found living in woman's brain in world's first case". 2023-08-28. Retrieved 2023-10-18.
  14. Germaine L Defendi (22 May 2023). "Gnathostomiasis" . Medscape.