Blastocystis is a genus of single-celled heterokont parasites belonging to a group of organisms ... It is the most common parasitic infection in the United States, where it infected approximately 23% of the total population during year 2000. ... Although the role of Blastocystis hominis in human disease is often referred to as ...BlastocystisFromWikipedia,thefreeencyclopediaJumptonavigationJumptosearchForthedisease,seeBlastocystosis.Forthestructureformedintheearlyembryogenesisofmammals,seeBlastocyst.BlastocystisBlastocystissp.ScientificclassificationDomain:Eukaryota(unranked):SARSuperphylum:HeterokontaClass:BlastocystaeOrder:BlastocystidaFamily:BlastocystidaeGenus:Blastocystis(Alexieff1911)Brumpt1912[1]Blastocystisisagenusofsingle-celledheterokontparasitesbelongingtoagroupoforganismsthatareknownastheStramenopiles(alsocalledHeterokonts)thatincludesalgae,diatoms,andwatermolds.Blastocystisconsistsofseveralspecies,livinginthegastrointestinaltractsofspeciesasdiverseashumans,farmanimals,birds,rodents,reptiles,amphibians,fish,andcockroaches.[2]Blastocystisexhibitslowhostspecificity,andmanydifferentspeciesofBlastocystiscaninfecthumans,[3]andbycurrentconvention,anyofthesespecieswouldbeidentifiedasBlastocystishominis.Blastocystisisoneofthemostcommonhumanparasitesintheworldandhasaglobaldistribution.[4][5][6][7]ItisthemostcommonparasiticinfectionintheUnitedStates,whereitinfectedapproximately23%ofthetotalpopulationduringyear2000.[6][7]Inlessdevelopedareas,infectionratesashighas100%havebeenobserved.[4][5]Highratesofinfectionarefoundinindividualsindevelopedcountrieswhoworkwithanimals.[5][8]AlthoughtheroleofBlastocystishominisinhumandiseaseisoftenreferredtoascontroversial,asystematicsurveyofresearchstudiesconductedby11infectiousdiseasespecialistsfromninecountries,foundthatover95%ofpaperspublishedinthe10yearsprioridentifieditascausingillnessinimmunocompetentindividuals.[7]Thepaperattributedconfusionoverpathogenicitytotheexistenceofasymptomaticcarriers,aphenomenonthestudynotediscommo