Title: Cryptosporidiosis

{{short description|Parasitic disease}}
{{distinguish|Cryptococcosis}}
{{Use dmy dates|date=May 2024}}
{{Infobox medical condition (new)
| name            = Cryptosporidiosis
| image           = Cryptosporidiosis - very high mag - cropped.jpg
| caption         = [[Micrograph]] showing cryptosporidiosis. The cryptosporidium are the small, round bodies in apical vacuoles on the surface of the epithelium. [[H&amp;E stain]]. [[Colon (anatomy)|Colonic]] [[biopsy]].
| pronounce       =
| field           = [[Infectious disease (medical specialty)|Infectious disease]]
| synonyms        =
| symptoms        = Watery diarrhea, nausea, abdominal pain, fever
| complications   =
| onset           =
| duration        =
| types           =
| causes          = [[Cryptosporidium]] infection
| risks           = [[Immunocompromisation]]
| diagnosis       =
| differential    =
| prevention      = Avoid contaminated water
| treatment       = [[Nitazoxanide]]
| medication      =
| prognosis       =
| frequency       =
| deaths          =
}}
'''Cryptosporidiosis''', sometimes informally called '''crypto''',&lt;ref name=cdc&gt;{{cite web |title=Cryptosporidiosis |publisher=Centers for Disease Control and Prevention |date=5 February 2009 |url=https://www.cdc.gov/crypto/ }}&lt;/ref&gt; is a [[parasitic disease]] caused by ''[[Cryptosporidium]]'', a genus of [[protozoa]]n [[parasite]]s in the phylum [[Apicomplexa]]. It affects the [[ileum|distal small intestine]] and can affect the [[respiratory tract]] in both [[immunocompetent]] (i.e., individuals with a normal functioning [[immune system]]) and [[immunocompromised]] (e.g., persons with [[HIV/AIDS]] or [[autoimmune disorders]]) individuals, resulting in [[diarrhea|watery diarrhea]] with or without an unexplained cough.&lt;ref name=&quot;Respiratory cryptosporidiosis - fomite transmission&quot;&gt;{{cite journal | vauthors = Sponseller JK, Griffiths JK, Tzipori S | title = The evolution of respiratory Cryptosporidiosis: evidence for transmission by inhalation | journal = Clin. Microbiol. Rev. | volume = 27 | issue = 3 | pages = 575–86 | year = 2014 | pmid = 24982322 | pmc = 4135895 | doi = 10.1128/CMR.00115-13 | quote =  Recent evidence indicates that respiratory cryptosporidiosis may occur commonly in immunocompetent children with cryptosporidial diarrhea and unexplained cough. Findings from animal models, human case reports, and a few epidemiological studies suggest that Cryptosporidium may be transmitted via respiratory secretions, in addition to the more recognized fecal-oral route.&amp;nbsp;... Upper respiratory cryptosporidiosis may cause inflammation of the nasal mucosa, sinuses, larynx, and trachea, accompanied by nasal discharge and voice change (54, 61, 62). Cryptosporidiosis of the lower respiratory tract typically results in productive cough, dyspnea, fever, and hypoxemia (63,–66).&amp;nbsp;... While fecal-oral transmission is indisputably the major route of infection, transmission via coughing and fomites is also possible in situations of close contact (20).&amp;nbsp;... Because they lacked gastrointestinal symptoms and oocyst excretion, the latter cases establish the possibility of primary respiratory infection with Cryptosporidium, which may have been acquired by inhalation of expectorated droplets or by contact with fomites.&amp;nbsp;... This finding suggests that respiratory cryptosporidiosis may occur commonly in immunocompetent individuals.}}&lt;/ref&gt; In immunosuppressed individuals, the symptoms are particularly severe and can be fatal. It is primarily spread through the [[fecal-oral route]], often through contaminated water;&lt;ref name=&quot;Respiratory cryptosporidiosis - fomite transmission&quot; /&gt;&lt;ref name=&quot;CDC risk factors&quot; /&gt; recent evidence suggests that it can also be transmitted via [[fomite]]s contaminated with respiratory secretions.&lt;ref name=&quot;Respiratory cryptosporidiosis - fomite transmission&quot; /&gt; ''Cryptosporidium'' is commonly isolated in [[HIV-positive]] patients presenting with diarrhea.&lt;ref&gt;{{cite journal |last1=Wang |first1=Ze-Dong |last2=Liu |first2=Quan |last3=Liu |first3=Huan-Huan |last4=Li |first4=Shuang |last5=Zhang |first5=Li |last6=Zhao |first6=Yong-Kun |last7=Zhu |first7=Xing-Quan |date=9 January 2018 |title=Prevalence of ''Cryptosporidium'', microsporidia and ''Isospora'' infection in HIV-infected people: a global systematic review and meta-analysis |journal=Parasites &amp; Vectors |volume=11 |issue=1 |page=28 |doi=10.1186/s13071-017-2558-x |pmc=5759777 |pmid=29316950 |doi-access=free}}&lt;/ref&gt;&lt;ref name=&quot;AhmadpourSafarpour2020&quot;&gt;{{cite journal |last1=Ahmadpour |first1=Ehsan |last2=Safarpour |first2=Hanie |last3=Xiao |first3=Lihua |last4=Zarean |first4=Mehdi |last5=Hatam-Nahavandi |first5=Kareem |last6=Barac |first6=Aleksandra |last7=Picot |first7=Stephane |last8=Rahimi |first8=Mohammad Taghi |last9=Rubino |first9=Salvatore |last10=Mahami-Oskouei |first10=Mahmoud |last11=Spotin |first11=Adel |last12=Nami |first12=Sanam |last13=Baghi |first13=Hossein Bannazadeh |year=2020 |title=Cryptosporidiosis in HIV-positive patients and related risk factors: A systematic review and meta-analysis |journal=Parasite |volume=27 |page=27 |doi=10.1051/parasite/2020025 |issn=1776-1042 |pmc=7191976 |pmid=32351207 |doi-access=free}}&lt;/ref&gt;

The organism was first described in 1907 by Tyzzer, who recognised it was a [[coccidia]]n.&lt;ref name=&quot;XiaoFayer2004&quot;&gt;{{cite journal |last1=Xiao |first1=L. |last2=Fayer |first2=R. |last3=Ryan |first3=U. |last4=Upton |first4=S. J. |year=2004 |title=Cryptosporidium Taxonomy: Recent Advances and Implications for Public Health |journal=Clinical Microbiology Reviews |volume=17 |issue=1 |pages=72–97 |doi=10.1128/CMR.17.1.72-97.2004 |issn=0893-8512 |pmc=321466 |pmid=14726456}}&lt;/ref&gt;

On January 8, 2025, a group of scientists from the Cryptosporidiosis Therapeutics Advocacy Group (CTAG) released an article in the newsletter ''Global Health NOW'' advocating for Cryptosporidiosis to be raised to the status of Neglected Tropical Disease (NTD) by the World Health Organization (WHO).&lt;ref&gt;{{Cite web |title=The Most Neglected NTD: Cryptosporidiosis {{!}} Global Health NOW |url=https://globalhealthnow.org/2025-01/most-neglected-ntd-cryptosporidiosis |access-date=2025-01-09 |website=globalhealthnow.org |language=en}}&lt;/ref&gt;

==Signs and symptoms==
Cryptosporidiosis may occur as an [[asymptomatic infection]], an acute infection (i.e., duration shorter than 2&amp;nbsp;weeks), as recurrent acute infections in which symptoms reappear following a brief period of recovery for up to 30&amp;nbsp;days, and as a chronic infection (i.e., duration longer than 2&amp;nbsp;weeks) in which symptoms are severe and persistent.&lt;ref name=&quot;Respiratory cryptosporidiosis - fomite transmission&quot; /&gt;&lt;ref name=&quot;CDC Crypto symptoms&quot; /&gt;&lt;ref name=&quot;MS Crypto presentation&quot; /&gt;&lt;ref name=&quot;CDC NTZ&quot; /&gt; It may be fatal in individuals with a severely compromised [[immune system]].&lt;ref name=&quot;Respiratory cryptosporidiosis - fomite transmission&quot; /&gt;&lt;ref name=&quot;CDC Crypto symptoms&quot; /&gt; [[Symptom]]s usually appear 5–10&amp;nbsp;days after infection (range: 2–28&amp;nbsp;days) and normally last for up to 2&amp;nbsp;weeks in [[immunocompetent]] individuals;&lt;ref name=&quot;Respiratory cryptosporidiosis - fomite transmission&quot; /&gt;&lt;ref name=&quot;CDC Crypto symptoms&quot; /&gt;&lt;ref name=&quot;MS Crypto presentation&quot; /&gt; symptoms are usually more severe and persist longer in [[immunocompromised]] individuals.&lt;ref name=&quot;Respiratory cryptosporidiosis - fomite transmission&quot; /&gt;&lt;ref name=&quot;CDC Crypto symptoms&quot; /&gt;&lt;ref name=&quot;MS Crypto presentation&quot; /&gt;  Following the resolution of diarrhea, symptoms can reoccur after several days or weeks due to reinfection.&lt;ref name=&quot;CDC Crypto symptoms&quot; /&gt;&lt;ref name=&quot;MS Crypto presentation&quot; /&gt;&lt;ref name=&quot;CDC NTZ&quot;&gt;{{cite web |title=Cryptosporidium: Nitazoxanide | publisher=United States Centers for Disease Control and Prevention | access-date=11 January 2016 |url=https://www.cdc.gov/parasites/crypto/nitazoxanide.html | date = 20 February 2015 | quote = Healthcare professionals might consider re-testing stool at least 1 week after the last dose of nitazoxanide only if symptoms do not resolve. In such cases, longer courses of treatment might be needed. Persistent symptoms may also represent re-infection }}&lt;/ref&gt;&lt;ref name=&quot;pmid25252476&quot; /&gt; The likelihood of {{nowrap|re-infection}} is high in immunocompromised adults, and low in those with normal immune systems.&lt;ref name=&quot;pmid25252476&quot; /&gt;&lt;ref&gt;{{cite journal|last1=Riggs|first1=Michael W|title=Recent advances in cryptosporidiosis: the immune response|journal=Microbes and Infection |date=August 2002|volume=4|issue=10|pages=1067–1080|doi=10.1016/S1286-4579(02)01631-3|pmid=12191657|doi-access=free}}&lt;/ref&gt;

In immunocompetent individuals, cryptosporidiosis is primarily localized to the [[ileum|distal small intestine]] and sometimes the [[respiratory tract]] as well.&lt;ref name=&quot;Respiratory cryptosporidiosis - fomite transmission&quot; /&gt;&lt;ref name=&quot;MS Crypto presentation&quot; /&gt;  In immunocompromised persons, cryptosporidiosis may disseminate to other organs, including the [[hepatobiliary system]], [[pancreas]], [[Human gastrointestinal tract#Upper gastrointestinal tract|upper gastrointestinal tract]], and [[urinary bladder]];&lt;ref name=&quot;Respiratory cryptosporidiosis - fomite transmission&quot; /&gt;&lt;ref name=&quot;MS Crypto presentation&quot; /&gt; pancreatic and biliary infection can involve [[cholecystitis|acalculous cholecystitis]], [[sclerosing cholangitis]], [[papillary stenosis]], or [[pancreatitis]].&lt;ref name=&quot;MS Crypto presentation&quot; /&gt;&lt;ref&gt;{{cite journal |vauthors=Hawkins S, Thomas R, Teasdale C |title=Acute pancreatitis: a new finding in cryptosporidium enteritis |journal=Br Med J (Clin Res Ed) |volume=294 |issue=6570 |pages=483–484 |year=1987 |pmid=3103738 |doi=10.1136/bmj.294.6570.483-a |pmc=1245527}}&lt;/ref&gt;

===Intestinal cryptosporidiosis===

Common signs and symptoms of intestinal cryptosporidiosis include:
* Moderate to severe watery [[diarrhea]],&lt;ref name=&quot;Respiratory cryptosporidiosis - fomite transmission&quot; /&gt;&lt;ref name=&quot;CDC Crypto symptoms&quot;&gt;{{cite web |title=Cryptosporidium: Illness &amp; Symptoms | publisher=United States Centers for Disease Control and Prevention | access-date=11 January 2016 |url=https://www.cdc.gov/parasites/crypto/illness.html | date = 20 February 2015}}&lt;/ref&gt;&lt;ref name=&quot;MS Crypto presentation&quot; /&gt; sometimes contains mucus and rarely contains blood or [[leukocytes]]&lt;ref name=&quot;MS Crypto presentation&quot;&gt;{{cite web|vauthors=Cabada MM, White AC, Venugopalan P, Sureshbabu J |editor=Bronze MS|title=Cryptosporidiosis Clinical Presentation|url=http://emedicine.medscape.com/article/215490-clinical#showall|website=Medscape|publisher=WebMD|access-date=8 January 2016|date=18 August 2015|quote=After an incubation period of 5–10 days (range 2–28 days), an infected individual develops watery diarrhea&amp;nbsp;... fever may be low grade or nonexistent;&amp;nbsp;... Diarrhea, with or without crampy abdominal pain, may be intermittent and scant or continuous, watery, and copious; sometimes, the diarrhea is mucoid.&amp;nbsp;... Biliary tract involvement is seen in persons with AIDS who have very low CD4 cell counts and is common in children with X-linked immunodeficiency with hyper–immunoglobulin M (IgM).&amp;nbsp;... Other signs related to GI illness include right upper-quadrant or epigastric tenderness, icterus, and, rarely, ascites related to pancreatic involvement. Reactive arthritis that affects the hands, knees, ankles, and feet has been described.}}&lt;/ref&gt;
** In very severe cases, diarrhea may be profuse and [[cholera]]-like with [[malabsorption]] and [[hypovolemia]]&lt;ref name=&quot;MS Crypto presentation&quot; /&gt;
* [[Low-grade fever]]&lt;ref name=&quot;Respiratory cryptosporidiosis - fomite transmission&quot; /&gt;&lt;ref name=&quot;CDC Crypto symptoms&quot; /&gt;&lt;ref name=&quot;MS Crypto presentation&quot; /&gt;
* Crampy [[abdominal pain]]&lt;ref name=&quot;Respiratory cryptosporidiosis - fomite transmission&quot; /&gt;&lt;ref name=&quot;CDC Crypto symptoms&quot; /&gt;&lt;ref name=&quot;MS Crypto presentation&quot; /&gt;
* Dehydration&lt;ref name=&quot;Respiratory cryptosporidiosis - fomite transmission&quot; /&gt;&lt;ref name=&quot;CDC Crypto symptoms&quot; /&gt;
* Weight loss&lt;ref name=&quot;Respiratory cryptosporidiosis - fomite transmission&quot; /&gt;&lt;ref name=&quot;CDC Crypto symptoms&quot; /&gt;
* Fatigue&lt;ref name=&quot;pmid25252476&quot; /&gt;
* Nausea and vomiting&lt;ref name=&quot;Respiratory cryptosporidiosis - fomite transmission&quot; /&gt;&lt;ref name=&quot;CDC Crypto symptoms&quot; /&gt;&lt;ref name=&quot;MS Crypto presentation&quot; /&gt; – suggests [[Human gastrointestinal tract#Upper gastrointestinal tract|upper GI tract]] involvement&lt;ref name=&quot;MS Crypto presentation&quot; /&gt; and may lead to respiratory cryptosporidiosis&lt;ref name=&quot;Respiratory cryptosporidiosis - fomite transmission&quot; /&gt;
* [[Epigastric]] or [[right upper quadrant (abdomen)|right upper quadrant]] [[tenderness (medicine)|tenderness]]&lt;ref name=&quot;MS Crypto presentation&quot; /&gt;

Less common or rare signs and symptoms include:
* [[Reactive arthritis]] (may affect the hands, knees, ankles, and feet)&lt;ref name=&quot;MS Crypto presentation&quot; /&gt;
* [[Jaundice]]&amp;nbsp;– suggests [[hepatobiliary]] involvement&lt;ref name=&quot;MS Crypto presentation&quot; /&gt;
* [[Ascites]]&amp;nbsp;– suggests [[pancreatic]] involvement&lt;ref name=&quot;MS Crypto presentation&quot; /&gt;

===Respiratory cryptosporidiosis===

Symptoms of [[upper respiratory tract infection|upper respiratory]] cryptosporidiosis include:
* [[Inflammation]] of the nasal mucosa, sinuses, larynx, or trachea&lt;ref name=&quot;Respiratory cryptosporidiosis - fomite transmission&quot; /&gt;
* Nasal discharge&lt;ref name=&quot;Respiratory cryptosporidiosis - fomite transmission&quot; /&gt;
* Voice change&lt;ref name=&quot;Respiratory cryptosporidiosis - fomite transmission&quot; /&gt; (e.g., [[hoarseness]])&lt;ref name=&quot;MS Crypto presentation&quot; /&gt;

Symptoms of [[Lower respiratory tract infection|lower respiratory]] cryptosporidiosis include:
* [[Cough]]&lt;ref name=&quot;Respiratory cryptosporidiosis - fomite transmission&quot; /&gt;&lt;ref name=&quot;MS Crypto presentation&quot; /&gt;
* [[Shortness of breath]]&lt;ref name=&quot;Respiratory cryptosporidiosis - fomite transmission&quot; /&gt;&lt;ref name=&quot;MS Crypto presentation&quot; /&gt;
* Fever&lt;ref name=&quot;Respiratory cryptosporidiosis - fomite transmission&quot; /&gt;
* [[Hypoxemia]]&lt;ref name=&quot;Respiratory cryptosporidiosis - fomite transmission&quot; /&gt;

==Cause==
[[Image:Cryptosporidiosis 01.png|thumb|300px|Life cycle of ''Cryptosporidium'' spp.]]
''[[Cryptosporidium]]'' is a genus of [[protozoan]] [[pathogen]]s which is categorized under the [[phylum]] [[Apicomplexa]]. Other apicomplexan pathogens include the [[malaria]] parasite ''[[Plasmodium]]'', and ''[[Toxoplasma]]'', the causative agent of [[toxoplasmosis]]. Several ''Cryptosporidium'' species infect mammals. In humans, the main causes of disease are ''C. parvum'' and ''C. hominis'' (previously ''C. parvum'' genotype 1). ''C. canis'', ''C. felis'', ''C. meleagridis'', and ''C. muris'' can also cause disease in humans. ''Cryptosporidium'' is capable of completing its life cycle within a single host, resulting in microbial cyst stages that are excreted in [[feces]] and are capable of transmission to a new host via the [[fecal-oral route]].  Other vectors of disease transmission also exist.&lt;ref name=&quot;Respiratory cryptosporidiosis - fomite transmission&quot; /&gt;&lt;ref&gt;{{cite journal |vauthors=Graczyk TK, Fayer R, Knight R |title=Mechanical transport and transmission of ''Cryptosporidium parvum'' oocysts by wild filth flies |journal=Am. J. Trop. Med. Hyg. |volume=63 |issue=3–4 |pages=178–83 |year=2000 |pmid=11388511 |display-authors=etal|doi=10.4269/ajtmh.2000.63.178 |doi-access=free }}&lt;/ref&gt;

The pattern of ''Cryptosporidium'' life cycle fits well with that of other intestinal homogeneous coccidian genera of the suborder ''[[Eimeriina]]'': macro- and microgamonts develop independently; a microgamont gives rise to numerous male gametes; and oocysts serve for parasites' spreading in the environment. Electron microscopic studies made from the 1970s have shown the intracellular, although extracytoplasmic localization of ''Cryptosporidium'' species.{{citation needed|date=May 2022}}

These species possess several unusual features:{{citation needed|date=May 2022}}
* an endogenous phase of development in microvilli of epithelial surfaces
* two morphofunctional types of oocysts
* the smallest number of sporozoites per oocyst
* a multi-membraneous &quot;feeder&quot; organelle

DNA studies suggest a relationship with the gregarines rather than the coccidia.&lt;ref name=&quot;Carreno1999&quot;&gt;{{cite journal|vauthors=Carreno RA, Martin DS, Barta JR |title=Cryptosporidium is more closely related to the gregarines than to coccidia as shown by phylogenetic analysis of apicomplexan parasites inferred using small-subunit ribosomal RNA gene sequences |journal=Parasitol. Res. |volume=85 |issue=11 |pages=899–904 |date=November 1999 |pmid=10540950 |url=http://link.springer.de/link/service/journals/00436/bibs/9085011/90850899.htm |doi=10.1007/s004360050655 |s2cid=11712486 |archive-url=https://web.archive.org/web/20010320224750/http://link.springer.de/link/service/journals/00436/bibs/9085011/90850899.htm |archive-date=20 March 2001 |url-access=subscription }}&lt;/ref&gt; The taxonomic position of this group has not yet been finally agreed upon.

The [[genome]] of ''Cryptosporidium parvum'' was sequenced in 2004 and was found to be unusual amongst [[Eukaryote]]s in that the [[mitochondria]] seem not to [[mitochondrial DNA|contain DNA]].&lt;ref&gt;{{cite journal |doi=10.1126/science.1094786 |title=Complete Genome Sequence of the Apicomplexan, ''Cryptosporidium parvum'' |year=2004 |author=Abrahamsen, M. S. |journal=Science |volume=304 |pages=441–5 |pmid=15044751 |last2=Templeton |first2=TJ |last3=Enomoto |first3=S |last4=Abrahante |first4=JE |last5=Zhu |first5=G |last6=Lancto |first6=CA |last7=Deng |first7=M |last8=Liu |first8=C |last9=Widmer |first9=G |last10=Tzipori |first10=S |last11=Buck |first11=G. A. |last12=Xu |first12=P |last13=Bankier |first13=A. T. |last14=Dear |first14=P. H. |last15=Konfortov |first15=B. A. |last16=Spriggs |first16=H. F. |last17=Iyer |first17=L |last18=Anantharaman |first18=V |last19=Aravind |first19=L |last20=Kapur |first20=V |s2cid=26434820 |issue=5669|bibcode=2004Sci...304..441A |display-authors=8 }}&lt;/ref&gt; A closely related species, ''C. hominis'', also has its genome sequence available.&lt;ref&gt;{{cite journal |doi=10.1038/nature02977 |title=The genome of ''Cryptosporidium hominis'' |year=2004 |journal=Nature |volume=431 |pages=1107–12 |pmid=15510150 |last2=Widmer |first2=G |last3=Wang |first3=Y |last4=Ozaki |first4=LS |last5=Alves |first5=JM |last6=Serrano |first6=MG |last7=Puiu |first7=D |last8=Manque |first8=P |last9=Akiyoshi |first9=D |last10=MacKey |first10=Aaron J. |last11=Pearson |first11=William R. |last12=Dear |first12=Paul H. |last13=Bankier |first13=Alan T. |last14=Peterson |first14=Darrell L. |last15=Abrahamsen |first15=Mitchell S. |last16=Kapur |first16=Vivek |last17=Tzipori |first17=Saul |last18=Buck |first18=Gregory A. |issue=7012|display-authors=8 |last1=Xu |first1=P. |bibcode=2004Natur.431.1107X |doi-access=free }}&lt;/ref&gt; CryptoDB.org is a [[NIH]]-funded database that provides access to the ''Cryptosporidium'' genomics data sets.&lt;ref&gt;{{Cite web |title=CryptoDB |url=https://cryptodb.org/cryptodb/app |access-date=2023-02-22 |website=cryptodb.org}}&lt;/ref&gt;

===Transfer===
[[Infection]] is through contaminated material such as earth, [[water]], uncooked or cross-contaminated [[food]] that has been in contact with the feces of an infected individual or [[animal]]. Contact must then be transferred to the mouth and swallowed. It is especially prevalent amongst those in regular contact with bodies of fresh water, including recreational water such as swimming pools. Other potential sources include insufficiently treated water supplies, contaminated food, or exposure to feces.&lt;ref name=&quot;CDC risk factors&quot; /&gt;  The high resistance of ''[[Cryptosporidium]]'' [[oocysts]] to [[disinfectant]]s such as [[chlorine]] [[bleach]] enables them to survive for long periods and remain infective.&lt;ref name=Carpenter_1999&gt;{{cite journal |last1=Carpenter |first1=Colleen |last2=Fayer |first2=Ronald |last3=Trout |first3=James |last4=Beach |first4=Michael J. |title=Chlorine Disinfection of Recreational Water for ''Cryptosporidium parvum'' |journal=Emerging Infectious Diseases |volume=5 |issue=4 |pages=579–84 |year=1999 |pmid=10458969 |pmc=2627758 |doi=10.3201/eid0504.990425 |bibcode=1999EIDis...5..579C }}&lt;/ref&gt; Some outbreaks have happened in day care related to diaper changes.&lt;ref&gt;{{cite journal |last1=Teresa Ortega |first1=María |last2=Vergara |first2=Alberto |last3=Guimbao |first3=Joaquín |last4=Clavel |first4=Antonio |last5=Gavín |first5=Patricia |last6=Ruiz |first6=Andrés |title=Brote de diarrea y transmisión de ''Cryptosporidium hominis'' asociados al uso de pañal en niños |trans-title=''Cryptosporidium hominis'' diarrhea outbreak and transmission linked to diaper infant use |language=es |journal=Medicina Clínica |volume=127 |issue=17 |pages=653–6 |year=2006 |pmid=17169283 |doi=10.1016/S0025-7753(06)72352-1 }}&lt;/ref&gt;

The following groups have an elevated risk of being exposed to ''Cryptosporidium'':&lt;ref name=&quot;CDC risk factors&quot;&gt;{{cite web |title=Cryptosporidium: Sources of Infection &amp; Risk Factors | publisher=United States Centers for Disease Control and Prevention | access-date=16 January 2016 |url=https://www.cdc.gov/parasites/crypto/infection-sources.html | date = 1 April 2015 }}&lt;/ref&gt;
* Child care workers
* Parents of infected children
* People who take care of other people with cryptosporidiosis
* International travelers
* Backpackers, hikers, and campers who drink unfiltered, untreated water
* People, including swimmers, who swallow water from contaminated sources
* People who handle infected cattle
* People exposed to human feces through sexual contact

Cases of cryptosporidiosis can occur even in cities that have a properly decontaminated water supply. In a city with clean water, it may be that cases of cryptosporidiosis have other origins.&lt;ref name=&quot;CDC risk factors&quot; /&gt; Testing of water, as well as [[epidemiological]] study, is necessary to determine the sources of specific infections. ''Cryptosporidium'' is causing serious illness &lt;ref name=Kelley_2014&gt;{{cite journal |last1=Kelley |first1=Amy S. |title=Defining &quot;Serious Illness&quot;  |journal=Journal of Palliative Medicine |volume=17 |issue=9 |page=985 |year=2014 |doi=10.1089/jpm.2014.0164|pmid=25115302 }}&lt;/ref&gt; more frequently in immunocompromised than in apparently healthy individuals. It may chronically sicken some children, as well as adults who are exposed and immunocompromised. A subset of the immunocompromised population is people with AIDS. Some sexual behaviors can transmit the parasite.&lt;ref name=&quot;CDC risk factors&quot; /&gt;

===Life cycle===
''[[Cryptosporidium]]'' [[spp.]] exist as multiple cell types which correspond to different stages in an infection (e.g., a sexual and asexual stage).&lt;ref name=cdc/&gt; As an [[oocyst]] – a type of hardy, thick-walled [[spore]] – it can survive in the environment for months and is resistant to many common disinfectants, particularly chlorine-based disinfectants.&lt;ref&gt;{{cite web |url=https://www.cdc.gov/ncidod/eid/vol5no4/carpenter.htm |title=Chlorine Disinfection of Recreational Water for ''Cryptosporidium parvum'' |publisher=CDC |access-date=6 May 2007}}&lt;/ref&gt;&lt;ref name=gideon&gt;{{cite web |title=Cryptosporidiosis |publisher=Gideon |date=23 February 2009 |url=http://web.gideononline.com/web/tox_diseases/index.php?disease=355&amp;view=General |quote=Trial subscription required to access |access-date=27 February 2009 |archive-date=27 April 2020 |archive-url=https://web.archive.org/web/20200427013531/https://web.gideononline.com/web/tox_diseases/index.php?disease=355&amp;view=General }}&lt;/ref&gt; After being ingested, the sporozoites within oocysts excyst (i.e., are released) in the small intestine.  The released sporozoites subsequently attach to the microvilli of the epithelial cells of the small intestine. From there, they become trophozoites that reproduce asexually by multiple fission, a process known as schizogony.  The trophozoites develop into Type 1 [[meront]]s [1] that contain 8 daughter cells.&lt;ref name=ryan&gt;{{cite book |author1=Ryan, Kenneth J. |author2=Ray, C. George |title=Sherris Medical Microbiology: An Introduction to Infectious Disease |publisher=McGraw-Hill|location=New York |year=2004 |pages=727–730 |edition=4th}}&lt;/ref&gt;

These daughter cells are Type 1 merozoites, which are released by the meronts. Some of these merozoites can cause autoinfection by attaching to epithelial cells.  Others of these merozoites become Type II meronts,&lt;ref name=&quot;ChenXM&quot;&gt;{{cite journal |vauthors=Chen XM, Keithly JS, Paya CV, LaRusso NF |title=Cryptosporidiosis |journal=N. Engl. J. Med. |volume=346|issue=22 |pages=1723–31 |date=May 2002 |pmid=12037153 |doi=10.1056/NEJMra013170}}&lt;/ref&gt; which contain 4 Type II merozoites.&lt;ref name=ryan/&gt;  These merozoites get released and they attach to the epithelial cells. From there, they become either macrogamonts or microgamonts.&lt;ref name=&quot;ChenXM&quot;/&gt;  These are the female and male sexual forms, respectively.&lt;ref name=ryan/&gt;  This stage, when sexual forms arise, is called gametogony.&lt;ref name=murray&gt;Murray, Patrick R., Ken S. Rosenthal, and Michael A. Pfaller. Medical Microbiology. 5th ed. Philadelphia: Elsevier Inc., 2005: 855–856.&lt;/ref&gt;

Zygotes are formed by [[microgamete]]s from the microgamont penetrating the macrogamonts. The zygotes develop into two types of oocysts.&lt;ref name=&quot;ChenXM&quot;/&gt;  20% of oocysts have thin walls and so can reinfect the host by rupturing and releasing sporozoites that start the process over again.&lt;ref name=ryan/&gt;  The thick-walled oocysts are excreted into the environment.&lt;ref name=&quot;ChenXM&quot;/&gt;  The oocysts are mature and infective upon being excreted.&lt;ref name=ryan/&gt;

==Pathogenesis==
The oocysts are ovoid or spherical and measure 5 to 6 micrometers across. When in flotation preparations, they appear highly refractile. The oocysts contain up to 4 sporozoites that are bow-shaped.&lt;ref name=winn&gt;{{cite book |author1=Winn Jr., Washington |author2=Allen, Stephen |author3=Janda, William |author4=Koneman, Elmer |author5=Procop, Gary |author6=Schreckenberger, Paul |author7=Woods, Gail |title=Koneman's Color Atlas and Textbook of Diagnostic Microbiology |publisher=Lippincott Williams &amp; Wilkins |location=Philadelphia |year=2006|pages=1267–70 |edition=6th}}&lt;/ref&gt;

As few as 2 to 10 oocysts can initiate an infection.&lt;ref name=&quot;ChenW&quot;/&gt;  The parasite is located in the brush border of the epithelial cells of the small intestine.&lt;ref name=brooks&gt;{{cite book |author1=Brooks, Geo. F. |author2=Butel, Janet S. |author3=Morse, Stephen A. |title=Jawetz, Melnick, &amp; Adelberg's Medical Microbiology |url=https://archive.org/details/isbn_9780071412070 |url-access=registration |publisher=Lange Medical Books/McGraw Hill |location=New York |year=2004 |pages=[https://archive.org/details/isbn_9780071412070/page/684 684–5]|isbn=978-0-07-141207-0 |edition=23rd}}&lt;/ref&gt;  They are mainly located in the jejunum.  When the sporozoites attach to the epithelial cells' membrane envelops them.  Thus, they are &quot;intracellular but extracytoplasmic&quot;.&lt;ref name=ryan/&gt;  The parasite can cause damage to the microvilli where it attaches.&lt;ref name=winn/&gt;  The infected human excretes the most oocysts during the first week.&lt;ref name=ryan/&gt;  Oocysts can be excreted for weeks after the diarrhea subsides from infections by ''C. parvum'' or ''C. hominis'';&lt;ref name=cdc/&gt; however, immunocompetent individuals with ''C. muris'' infections have been observed excreting oocysts for seven months.&lt;ref name=&quot;C. muris&quot;&gt;{{cite journal |vauthors=Chappell CL, Okhuysen PC, Langer-Curry RC, Lupo PJ, Widmer G, Tzipori S |title=Cryptosporidium muris: infectivity and illness in healthy adult volunteers |journal=Am. J. Trop. Med. Hyg. |volume=92 |issue=1 |pages=50–55 |year=2015 |pmid=25311695 |pmc=4347390 |doi=10.4269/ajtmh.14-0525 |quote=C. muris-infected subjects shed oocysts longer than occurred with other species studied in healthy volunteers. Three volunteers shed oocysts for 7 months.&amp;nbsp;... Thus, healthy adults are susceptible to C. muris, which can cause mild diarrhea and result in persistent, asymptomatic infection.}}&lt;/ref&gt;

The immune system reduces the formation of Type 1 merozoites as well as the number of thin-walled oocysts.&lt;ref name=ryan/&gt;  This helps prevent autoinfection. B cells do not help with the initial response or the fight to eliminate the parasite.&lt;ref name=&quot;ChenW&quot;&gt;{{cite journal |vauthors=Chen W, Harp JA, Harmsen AG |title=Cryptosporidium parvum infection in gene-targeted B cell-deficient mice |journal=J. Parasitol. |volume=89 |issue=2 |pages=391–3 |date=April 2003 |pmid=12760662 |doi=10.1645/0022-3395(2003)089[0391:CPIIGB]2.0.CO;2|s2cid=11523340 }}&lt;/ref&gt;
Previous infection in immunocompetent individuals produces little resistance to future infection; however, it may decrease the severity of disease and the number of oocysts excreted.&lt;ref name = &quot;clark&quot;&gt;{{cite journal |last1=Clark|first1=Douglas P.|title=New Insights into Human Cryptosporidiosis|journal=Clinical Microbiology Reviews|date=1 October 1999|volume=12|issue=4|pages=554–563|issn=0893-8512 |doi=10.1128/CMR.12.4.554|pmid=10515902 |pmc=88924 |bibcode=1999CliMR..12..554C }}&lt;/ref&gt;&lt;ref name = &quot;okhuysen&quot;&gt;{{cite journal |last1=Okhuysen|first1=Pablo C.|last2=Chappell|first2=Cynthia L.|last3=Sterling|first3=Charles R. |last4=Jakubowski|first4=Walter|last5=DuPont|first5=Herbert L. |title=Susceptibility and Serologic Response of Healthy Adults to Reinfection with Cryptosporidium parvum|journal=Infection and Immunity|date=1 February 1998|volume=66|issue=2|pages=441–443|doi=10.1128/IAI.66.2.441-443.1998 |issn=0019-9567|pmid=9453592 |pmc=107924}}&lt;/ref&gt;

==Diagnosis==
There are many diagnostic tests for ''Cryptosporidium''.  They include microscopy, staining, and detection of [[antibodies]]. [[Microscopy]]&lt;ref name=cdc/&gt; can help identify oocysts in fecal matter.&lt;ref name=brooks/&gt;  To increase the chance of finding the oocysts, the diagnostician should inspect at least 3 stool samples.&lt;ref name=murray/&gt;  There are several techniques to concentrate either the stool sample or the oocysts.  The modified [[formalin-ethyl acetate]] (FEA) concentration method concentrates the stool.&lt;ref name=winn/&gt;  Both the modified zinc sulfate centrifugal flotation technique and the Sheather's sugar flotation procedure can concentrate the oocysts by causing them to float.&lt;ref name=murray/&gt;  Another form of microscopy is [[fluorescent microscopy]] done by staining with [[auramine]].&lt;ref name=brooks/&gt;

Other staining techniques include [[acid-fast stain]]ing,&lt;ref name=&quot;ChenW&quot;/&gt; which will stain the oocysts red.&lt;ref name=winn/&gt;  One type of acid-fast stain is the [[Kinyoun stain]].&lt;ref name=gideon/&gt;  [[Giemsa stain]]ing can also be performed.&lt;ref name=ryan/&gt;  Part of the small intestine can be stained with [[hematoxylin]] and [[eosin]] (H &amp; E), which will show oocysts attached to the [[epithelial cell]]s.&lt;ref name=winn/&gt;

Detecting [[antigen]]s is yet another way to diagnose the disease.  This can be done with [[direct fluorescent antibody]] (DFA) techniques.&lt;ref name=cdc/&gt;  It can also be achieved through [[Immunofluorescence#Secondary (indirect)|indirect immunofluorescence]] assay.&lt;ref name=murray/&gt;  [[Enzyme-linked immunosorbent assay]] (ELISA) also detects antigens.&lt;ref name=brooks/&gt;

[[Polymerase chain reaction]] (PCR) is another way to diagnose cryptosporidiosis.  It can even identify the specific species of ''Cryptosporidium''.&lt;ref name=cdc/&gt;  If the patient is thought to have biliary cryptosporidiosis, then an appropriate diagnostic technique is [[ultrasonography]].  If that returns normal results, the next step would be to perform [[endoscopic retrograde cholangiopancreatography]].&lt;ref name=&quot;ChenW&quot;/&gt;

== Prevention ==
Many [[Water purification|treatment plants]] that take raw water from [[river]]s, [[lake]]s, and [[reservoir (water)|reservoirs]] for public [[drinking water]] production use conventional filtration technologies. This involves a series of processes, including [[coagulation]], [[flocculation]], [[sedimentation]], and [[filtration]]. Direct filtration, which is typically used to treat water with low particulate levels, includes coagulation and filtration, but not sedimentation. Other common filtration processes, including [[slow sand filter]]s,  [[diatomaceous earth|diatomaceous earth filter]]s, and membranes will remove 99% of ''Cryptosporidium''.&lt;ref&gt;{{cite web|url=http://www.epa.gov/safewater/mdbp/ieswtrwhatdoesitmeantoyou.pdf |title=The Interim Enhanced Surface Water Treatment Rule – What Does it Mean to You? |publisher=USEPA |access-date=6 May 2007 |archive-url=https://web.archive.org/web/20070928042810/http://www.epa.gov/safewater/mdbp/ieswtrwhatdoesitmeantoyou.pdf |archive-date=28 September 2007 }}&lt;/ref&gt; Membranes and bag and cartridge filters remove ''Cryptosporidium''  product-specifically.{{citation needed|date=June 2021}}

While ''Cryptosporidium'' is highly resistant to chlorine disinfection,&lt;ref&gt;{{cite journal |vauthors=Korich DG, Mead JR, Madore MS, Sinclair NA, Sterling CR |title=Effects of ozone, chlorine dioxide, chlorine, and monochloramine on Cryptosporidium parvum oocyst viability |journal=Appl. Environ. Microbiol. |volume=56 |issue=5 |pages=1423–8 |date=May 1990 |doi=10.1128/AEM.56.5.1423-1428.1990 |pmid=2339894 |pmc=184422 |bibcode=1990ApEnM..56.1423K }}&lt;/ref&gt; with high enough concentrations and contact time, ''Cryptosporidium'' will be inactivated by [[chlorine dioxide]] and ozone treatment. The required levels of chlorine generally preclude the use of chlorine disinfection as a reliable method to control ''Cryptosporidium'' in drinking water. Ultraviolet light treatment at relatively low doses will inactivate ''Cryptosporidium''. Water Research Foundation-funded research originally discovered UV's efficacy in inactivating ''Cryptosporidium''.&lt;ref&gt;{{cite journal | title=Irreversible UV inactivation of ''Cryptosporidium'' spp. despite the presence of UV repair genes |pmid=15537090 |journal=J Eukaryot Microbiol |date=September–October 2004 |volume=51 |issue=5 |pages=553–562 |doi=10.1111/j.1550-7408.2004.tb00291.x |vauthors=Rochelle PA, Fallar D, Marshall MM, Montelone BA, Upton SJ, Woods K |bibcode=2004JEukM..51..553R |s2cid=32841562|doi-access=free }}&lt;/ref&gt;&lt;ref&gt;{{cite web |title=Ultraviolet Disinfection and Treatment |url=http://www.waterresearchfoundation.org/research/TopicsAndProjects/topicSnapshot.aspx?topic=uv |publisher=WaterResearchFoundation (formerly AwwaRF) |access-date=6 May 2007 |archive-url=https://web.archive.org/web/20090124050926/http://www.waterresearchfoundation.org/research/TopicsAndProjects/topicSnapshot.aspx?topic=uv |archive-date=24 January 2009}}&lt;/ref&gt;

One of the largest challenges in identifying outbreaks is the ability to identify ''Cryptosporidium'' in the [[laboratory]].  Real-time monitoring technology is now able to detect ''Cryptosporidium'' with online systems, unlike the spot and batch testing methods used in the past.{{citation needed|date=May 2022}}

The most reliable way to decontaminate drinking water that may be contaminated by ''Cryptosporidium'' is to boil it.&lt;ref&gt;{{cite news |url=https://news.bbc.co.uk/2/hi/uk_news/wales/7589839.stm |title=Boil water warning 'precaution' |publisher=BBC|access-date=7 September 2009 | date=2 September 2008}}&lt;/ref&gt;&lt;ref&gt;{{cite news|url=https://news.bbc.co.uk/2/hi/uk_news/wales/4484946.stm |title=Boil water 'into January' warning  |publisher=BBC |access-date=7 September 2009 | date=30 November 2005}}&lt;/ref&gt;

In the US the law requires doctors and labs to report cases of cryptosporidiosis to local or state health departments.  These departments then report to the [[Centers for Disease Control and Prevention]].&lt;ref name=cdc/&gt;  The best way to prevent getting and spreading cryptosporidiosis is to have good hygiene and sanitation.&lt;ref name=murray/&gt;  An example would be hand-washing.&lt;ref name=cdc/&gt;  Prevention is through washing hands carefully after going to the bathroom or contacting [[feces|stool]], and before eating.  People should avoid contact with animal feces.&lt;ref name=&quot;brooks&quot;/&gt;  They should also avoid possibly contaminated food and water.&lt;ref name=cdc/&gt;  In addition, people should refrain from engaging in sexual activities that can expose them to feces.&lt;ref name=murray/&gt;

Standard water filtration may not be enough to eliminate ''Cryptosporidium''; boiling for at least 1 minute (3 minutes above {{convert|6500|ft|m}} of altitude) will decontaminate it.  Heating milk at 71.7&amp;nbsp;°C (161&amp;nbsp;°F) for 15 seconds pasteurizes it and can destroy the oocysts' ability to infect.&lt;ref name=text&gt;John, David T. and William A. Petri, Jr. Markell and Voge's Medical Parasitology. 9th ed. Philadelphia: Elsevier Inc., 2006: 68–71.&lt;/ref&gt;  Water can also be made safe by filtering with a filter with pore size not greater than 1 micrometre, or by filters that have been approved for &quot;cyst removal&quot; by NSF International [[National Sanitation Foundation]].&lt;ref name=cdc/&gt;  Bottled drinking water is less likely to contain ''Cryptosporidium'', especially if the water is from an underground source.&lt;ref name=text/&gt;

People with cryptosporidiosis should not swim in communal areas because the pathogen can reside in the anal and genital areas and be washed off.  They should wait until at least two weeks after diarrhea stops before entering public water sources, since oocysts can still be shed for a while.  Also, they should stay away from immunosuppressed people.&lt;ref name=cdc/&gt;  Immunocompromised people should take care to protect themselves from water in lakes and streams.&lt;ref name=&quot;ChenW&quot;/&gt;  They should also stay away from animal stools and wash their hands after touching animals.  To be safe, they should boil or filter their water.  They should also wash and cook their vegetables.&lt;ref name=cdc/&gt;

The US CDC notes the recommendation of many public health departments to soak contaminated surfaces for 20 minutes with a 3% [[hydrogen peroxide]]{{Clarify|reason=|date=November 2020}} (99% kill rate) and then rinse them thoroughly, with the caveat that no disinfectant is guaranteed to be completely effective against Cryptosporidium. However, hydrogen peroxide is more effective than standard bleach solutions.&lt;ref&gt;{{cite web|url=https://www.cdc.gov/parasites/crypto/daycare/outbreak.html|title=Control measures for Outbreaks — Intensified Cryptosporidiosis (Crypto) Control Measures for the Child Care Setting|publisher = US Centers for Disease Control and Prevention|date=7 January 2019}}&lt;/ref&gt;

==Treatment==
[[Symptomatic treatment]] primarily involves [[management of dehydration|fluid rehydration]], [[oral rehydration therapy|electrolyte replacement]] (sodium, potassium, bicarbonate, and glucose), and [[antimotility agent]]s (e.g., [[loperamide]]).&lt;ref name=&quot;MS Crypto treatment&quot; /&gt;&lt;ref name=&quot;Cochrane immunocompromised&quot; /&gt;  Supplemental zinc may improve symptoms,&lt;ref name=&quot;MS Crypto treatment&quot;&gt;{{cite web|vauthors=Cabada MM, White AC, Venugopalan P, Sureshbabu J |editor=Bronze MS|title=Cryptosporidiosis Treatment &amp; Management|url=http://emedicine.medscape.com/article/215490-treatment#showall|website=Medscape|publisher=WebMD|access-date=8 January 2016|date=18 August 2015|quote=Infection may improve with nutritional supplementation, particularly with regimens including zinc or glutamine.&amp;nbsp;... Nitazoxanide significantly shortens the duration of diarrhea and can decrease the risk of mortality in malnourished children.[22] Trials have also demonstrated efficacy in adults.[26, 27]&amp;nbsp;... Use of partially active antiparasitic drugs (eg, nitazoxanide or paromomycin combined with azithromycin) should be considered along with initiating antiretroviral therapy.&amp;nbsp;... Symptomatic therapy includes replacement of fluids, provision of appropriate nutrition, and treatment with antimotility agents.&amp;nbsp;... Replacement of fluids and electrolytes is the critically important first step in the management of cryptosporidiosis, particularly in patients with large diarrheal losses. Fluids should include sodium, potassium, bicarbonate, and glucose.}}&lt;/ref&gt; particularly in recurrent or persistent infections or in others at risk for [[zinc deficiency]].

===Immunocompetent===

[[Immunocompetent]] individuals with cryptosporidiosis typically experience a short (i.e., duration of less than 2 weeks) self-limiting course of diarrhea that may require [[symptomatic treatment]] and ends with spontaneous recovery; in some circumstances, antiparasitic medication may be required (e.g., recurrent, severe, or persistent symptoms);&lt;ref name=&quot;pmid25252476&quot; /&gt; however reinfection frequently occurs.&lt;ref name=&quot;pmid25252476&quot;&gt;{{cite journal | vauthors = Ali S, Mumar S, Kalam K, Raja K, Baqi S | title = Prevalence, clinical presentation and treatment outcome of cryptosporidiosis in immunocompetent adult patients presenting with acute diarrhoea | journal = J Pak Med Assoc | volume = 64 | issue = 6 | pages = 613–8 | year = 2014 | pmid = 25252476 | quote =  All 58 patients reported resolution of diarrhoea after 7 days of treatment with nitazoxanide. However, 40 (70.1%) patients reported recurrence of diarrhoea within 6 weeks of treatment.&amp;nbsp;... Our study demonstrates a high prevalence of cryptosporidiosis in immunocompetent adult patients. Nitazoxanide is the recommended antimicrobial drug for cryptosporidiosis.&amp;nbsp;... The frequency of cryptosporidiosis has not been well-defined. About 30% of the adult population of the United States is seropositive, with over 10,500 cases reported in 2008.&amp;nbsp;... Although we gave 7 days of therapy, and a satisfactory treatment response was obtained in the short term, there was a high recurrence rate.21 Paromomycin and/or azithromycin in combination with nitazoxanide have been tested in double blind randomized trials for the treatment of cryptosporidiosis in immunocompromised patients, such as those with HIV/AIDS, and the results have been encouraging.18,22,23}}&lt;/ref&gt;

{{As of|2015}}, [[nitazoxanide]] is the only [[antiparasitic]] drug treatment with proven efficacy for cryptosporidiosis in immunocompetent individuals;&lt;ref name=&quot;pmid25252476&quot; /&gt;&lt;ref name=&quot;MS Crypto treatment&quot; /&gt;&lt;ref name=&quot;Cochrane immunocompromised&quot;&gt;{{cite journal | vauthors = Abubakar I, Aliyu SH, Arumugam C, Hunter PR, Usman NK | title = Prevention and treatment of cryptosporidiosis in immunocompromised patients | journal = Cochrane Database Syst Rev | issue = 1 | article-number = CD004932 | date = January 2007 | volume = 2012 | pmid = 17253532 | doi = 10.1002/14651858.CD004932.pub2 | pmc = 12042072 | quote =  The results indicate that nitazoxanide reduces the load of parasites and may be useful in immunocompetent individuals. Due to the seriousness of the potential outcomes of cryptosporidiosis, the use of nitazoxanide should be considered in immunocompromised patients. The absence of effective therapy highlights the need to ensure that infection is avoided.&amp;nbsp;... For HIV-infected persons, highly active antiretroviral therapy (HAART) is the mainstay of preventing and managing cryptosporidiosis. HAART can lead to complete resolution of clinical symptoms and oocysts (Grube 1997; Maggi 2000; Miao 2000). This intervention is not available for HIV patients who are failing HAART or those unable to access HAART in developing countries. Among these immunocompromised persons without the option of an effective treatment for the underlying disease, supportive management, including rehydration therapy, electrolyte replacement, and anti-motility agents, will remain the only alternatives for care until better drugs emerge. | url = https://researchonline.lshtm.ac.uk/462/1/Abubakar_et_al-2007-The_Cochrane_library.pdf }}&lt;/ref&gt;&lt;ref name=&quot;pmid26568906&quot;&gt;{{cite journal | vauthors = Sparks H, Nair G, Castellanos-Gonzalez A, White AC | title = Treatment of Cryptosporidium: What We Know, Gaps, and the Way Forward | journal = Curr Trop Med Rep | volume = 2 | issue = 3 | pages = 181–187 | year = 2015 | pmid = 26568906 | doi = 10.1007/s40475-015-0056-9 | pmc = 4640180 }}&lt;/ref&gt; however, it lacks efficacy in severely [[immunocompromised]] patients.&lt;ref name=&quot;pmid26568906&quot; /&gt; Certain agents such as [[paromomycin]] and [[azithromycin]] are sometimes used as well, but they only have partial efficacy.&lt;ref name=&quot;MS Crypto treatment&quot; /&gt;

===Immunocompromised===
In [[immunocompromised]] individuals, such as AIDS patients, cryptosporidiosis resolves slowly or not at all. It frequently causes a particularly severe and persistent form of watery diarrhea coupled with a greatly decreased ability to absorb key nutrients through the intestinal tract. As a result, infected individuals may experience severe dehydration, electrolyte imbalances, malnutrition, wasting, and potentially death. In general, the mortality rate for infected AIDS patients is based on [[CD4+]] marker counts. Patients with CD4+ counts over 180 cells/mm&lt;sup&gt;3&lt;/sup&gt; recover with supportive hospital care and medication; but, in patients with CD4+ counts below 50 cells/mm&lt;sup&gt;3&lt;/sup&gt;, the effects are usually fatal within 3 to 6&amp;nbsp;months. During the [[1993 Milwaukee cryptosporidiosis outbreak]] (the largest of its kind), 73% of AIDS patients with CD4+ counts lower than 50 cells/mm&lt;sup&gt;3&lt;/sup&gt; and 36% of those with counts between 50 and 200 cells/mm&lt;sup&gt;3&lt;/sup&gt; died within the first year of contracting the infection.&lt;ref&gt;{{cite journal |first=Ian |last=Gilson M.D. |author2=Buggy, Brian P. M.D. |title=Cryptosporidiosis in Patients with HIV Disease: Is It Safe to Drink the Water? |date=October 1996 |journal=HIV Newsline |url=http://www.thebody.com/content/art12553.html}}&lt;/ref&gt;

In individuals with HIV and cryptosporidiosis, the '''primary treatment''' is the prompt initiation of '''effective antiretroviral therapy (ART)''' to restore immune function, typically using an '''integrase strand transfer inhibitor (INSTI)–based regimen''' rather than older protease-inhibitor combinations (National Institutes of Health, 2025). Restoration of immune competence is the single most important factor in clearing infection.

'''Supportive care'''—including hydration, nutritional maintenance, and symptom control—is essential. '''Nitazoxanide''' may be considered as an adjunct, although its '''benefit in immunocompromised individuals remains limited''', and clinical studies have shown reduced or absent efficacy in patients with advanced HIV (Centers for Disease Control and Prevention [CDC], 2025a). Evidence for other antiparasitic agents such as '''paromomycin''' or '''azithromycin''' is inconclusive; none have demonstrated consistent benefit in people with severe immune suppression (CDC, 2025b).

Older reviews, such as the Cochrane Collaboration analysis, noted potential activity of nitazoxanide primarily in '''immunocompetent''' hosts and regarded its use in immunocompromised individuals as '''experimental or adjunctive''' rather than standard therapy. Current guidelines emphasize that '''immune reconstitution through ART''', not antiparasitic drug therapy, remains the cornerstone of management.

Currently, research is being done in molecular-based [[immunotherapy]].  For example, synthetic isoflavone derivatives have been shown to fight off ''Cryptosporidium parvum'' both ''in vitro'' and in animal studies.&lt;ref&gt;{{Cite journal|last1=Stachulski|first1=Andrew V.|last2=Berry|first2=Neil G.|last3=Lilian Low|first3=A. C.|last4=Moores|first4=Shelley L.|last5=Row|first5=Eleanor|last6=Warhurst|first6=David C.|last7=Adagu|first7=Ipemida S.|last8=Rossignol |first8=Jean-François|date=2006-02-01|title=Identification of Isoflavone Derivatives as Effective Anticryptosporidial Agents in Vitro and in Vivo|journal=Journal of Medicinal Chemistry |volume=49|issue=4|pages=1450–1454|doi=10.1021/jm050973f|pmid=16480281 |issn=0022-2623}}&lt;/ref&gt;  Derivates of nitazoxanide, known as [[thiazolide]]s, have also shown promising results ''in vitro''.&lt;ref name=gargala&gt;{{cite journal |author=Gargala G |title=Drug treatment and novel drug target against Cryptosporidium |journal=Parasite |volume=15 |issue=3 |pages=275–81 |date=September 2008 |pmid=18814694 |doi=10.1051/parasite/2008153275 |doi-access=free }}&lt;/ref&gt; rifaximin is also sometimes used for immunocompromised patients/patients with severe disease.

==Epidemiology==
Cryptosporidiosis is found worldwide. It causes 50.8% of water-borne diseases that are attributed to parasites.&lt;ref name=gideon/&gt; In developing countries, 8–19% of diarrheal diseases can be attributed to ''Cryptosporidium''.&lt;ref name=gatei&gt;{{cite journal |vauthors=Gatei W, Wamae CN, Mbae C |title=Cryptosporidiosis: prevalence, genotype analysis, and symptoms associated with infections in children in Kenya |journal=Am. J. Trop. Med. Hyg. |volume=75 |issue=1|pages=78–82 |date=July 2006 |pmid=16837712 |url=http://www.ajtmh.org/cgi/pmidlookup?view=long&amp;pmid=16837712|display-authors=etal|doi=10.4269/ajtmh.2006.75.78 |bibcode=2006AJTMH..75...78G |doi-access=free |url-access=subscription }}&lt;/ref&gt; Ten percent of the population in developing countries excretes oocysts. In developed countries, the number is lower at 1–3%. The age group most affected is children from 1 to 9 years old.&lt;ref name=&quot;ChenW&quot;/&gt;&lt;ref name=Loz2012&gt;{{cite journal|vauthors=Lozano R |title=Global and regional mortality from 235 causes of death for 20 age groups in 1990 and 2010: a systematic analysis for the Global Burden of Disease Study 2010.|journal=Lancet|date=15 December 2012|volume=380|issue=9859 |pages=2095–2128|pmid=23245604|doi=10.1016/S0140-6736(12)61728-0|pmc=10790329 |hdl=10536/DRO/DU:30050819|s2cid=1541253|url=https://zenodo.org/record/2557786|hdl-access=free}}&lt;/ref&gt;

In Eastern Europe, cryptosporidiosis in humans and animals is common, but there are considerable gaps in surveillance and a lack of comparable methods, which limit the understanding of the disease and the detection of outbreaks. Research shows a rich diversity of zoonotic subtypes of the parasite in animals, indicating a rich potential of animal-to-human transmission.
&lt;ref name=&quot;surveillance&quot;&gt;{{cite journal | last1 = Plutzer | first1 = J. | last2 = Lassen| first2 = B. | last3 = Jokelainen | first3 = P. | last4 = Djurković-Djaković | first4 = O. | last5 = Kucsera | first5 = I. | last6 = Dorbek-Kolin | first6 = E. | last7 = Šoba | first7 = B. | last8 = Sréter | first8 = T. | last9 = Imre | first9 = K. | last10 = Omeragić | first10 = J. | last11 = Nikolić | first11 = A. | last12 = Bobić | first12 = B. | last13 = Živičnjak | first13 = T. | last14 = Lučinger | first14 = S. | last15 = Lazarić Stefanović | first15 = L. | last16 = Kučinar | first16 = J. | last17 = Sroka | first17 = J. | last18 = Deksne | first18 = G. | last19 = Keidāne | first19 = D. | last20 = Kváč | first20 = M. | last21 = Hůzová | first21 = Z. | last22 = Panagiotis | first22 = K. | year = 2018 | title = Review of ''Cryptosporidium'' and ''Giardia'' in the eastern part of Europe, 2016 | doi =  10.2807/1560-7917.ES.2018.23.4.16-00825 | journal = Euro Surveill | volume = 23| issue = 4 | pmid = 29382412 | pmc = 5801338 }}&lt;/ref&gt;&lt;ref name=&quot;cparvum&quot;&gt;{{cite journal | last1 = Santoro| first1 = A. | last2 = Dorbek-Kolin| first2 = E. | last3 = Jeremejeva| first3 = J. | last4 = Tummeleht| first4 = L.| last5 = Orro| first5 = T.| last6 = Jokelainen| first6 = P.| last7 = Lassen| first7 = B.|year = 2019 | title = Molecular epidemiology of Cryptosporidium spp. in calves in Estonia: high prevalence of Cryptosporidium parvum shedding and 10 subtypes identified | doi =10.1017/S0031182018001348  | url =https://www.cambridge.org/core/journals/parasitology/article/molecular-epidemiology-of-cryptosporidium-spp-in-calves-in-estonia-high-prevalence-of-cryptosporidium-parvum-shedding-and-10-subtypes-identified/B29F22F1BA93225AFFA343573D6FAB41 | journal = Parasitology| volume = 146| issue = 2 | pages = 261–267 | pmid =30086806  | s2cid = 51933975 | url-access = subscription}}&lt;/ref&gt; For example, the subtype IId of ''C. parvum'' is considered highly virulent compared to subtype IIa of the same species. Subtype IId caused severe damage to intestinal epithelial barrier and pathological changes in a study done with neonatal mice. In addition, the oocyst shedding window was wider and the infection period was longer in subtype IId compared to subtype IIa.&lt;ref&gt;{{Cite journal |last1=Luo |first1=Chaowei |last2=Xu |first2=Yanhua |last3=Zhang |first3=Jie |last4=Tian |first4=Qing |last5=Guo |first5=Yaqiong |last6=Li |first6=Na |last7=Feng |first7=Yaoyu |last8=Xu |first8=Rui |last9=Xiao |first9=Lihua |date=2024-05-24 |title=Cryptosporidium parvum disrupts intestinal epithelial barrier in neonatal mice through downregulation of cell junction molecules |journal=PLOS Neglected Tropical Diseases |language=en |volume=18 |issue=5 |article-number=e0012212 |doi=10.1371/journal.pntd.0012212 |doi-access=free |issn=1935-2735 |pmc=11156435 |pmid=38787872}}&lt;/ref&gt;

Roughly 30% of adults in the United States are [[seropositive]] for cryptosporidiosis, meaning that they contracted the infection at some point in their lives.&lt;ref name=&quot;pmid25252476&quot; /&gt;&lt;!--  Statistics for the United States — number of cases:&lt;ref name=gideon/&gt;
{| class=&quot;wikitable&quot;
|-
! Year !! Cases
|-
| 2006 || align=&quot;right&quot; | 5,936
|-
| 2007 || align=&quot;right&quot; | 11,170
|-
| 2008 || align=&quot;right&quot; | 7,749
|}
--&gt;

==Research==
A recombinant ''Cryptosporidium parvum'' [[oocyst]] surface protein ([[rCP15/60]]) vaccine has produced an antibody response in a large group of cows and also an antibody response in calves fed rCP15/60-immune [[colostrum]] produced by these vaccinated cows.  This is very promising.  Human ''Cryptosporidium parvum'' infections are particularly prevalent and often fatal in infants in developing countries and to [[immunocompromised]] people, such as AIDS patients.  There is no commercially available effective vaccine against ''Cryptosporidium parvum'', although passive immunization utilizing different zoite surface (glyco)proteins has shown promise.  Developmental stages of the life cycle of the parasite might act as possible targets for vaccine development. The organism is detected in 65–97% of the [[surface-water]] supply in the United States and is resistant to most disinfectants used for the treatment of drinking water. [[Antibodies]] in the serum of humans and animals infected with ''Cryptosporidium parvum'' react with several antigens, one of which is a 15&amp;nbsp;{{abbrlink|kDa|kilodalton}} protein ([[CP15]]) located on the surface of the organism. This protein is a good candidate for use as a molecular vaccine because previous studies have shown that a [[monoclonal antibody]] to CP15 confers [[passive immunity]] to mice.  Currently, there is no vaccine or completely effective drug therapy against ''Cryptosporidium parvum'' in HIV/AIDS individuals.&lt;ref name=&quot;MS Crypto treatment&quot; /&gt;&lt;ref name=&quot;Cochrane immunocompromised&quot; /&gt;

A summary of discoveries presented at the most recent (June 2019) international symposium on ''Cryptosporidium'' has been published in 2020.&lt;ref name=&quot;WidmerCarmena2020&quot;&gt;{{cite journal|last1=Widmer |first1=Giovanni|last2=Carmena |first2=David|last3=Kváč|first3=Martin|last4=Chalmers|first4=Rachel M. |last5=Kissinger|first5=Jessica C.|last6=Xiao|first6=Lihua|last7=Sateriale|first7=Adam|last8=Striepen |first8=Boris|last9=Laurent|first9=Fabrice|last10=Lacroix-Lamandé|first10=Sonia|last11=Gargala |first11=Gilles|last12=Favennec|first12=Loïc|title=Update on ''Cryptosporidium'' spp.: highlights from the Seventh International Giardia and Cryptosporidium Conference|journal=Parasite|volume=27 |year=2020|page=14 |issn=1776-1042|doi=10.1051/parasite/2020011|pmid=32167464|pmc=7069357|doi-access=free}}&lt;/ref&gt;

==In animals==
The most important [[zoonotic]] reservoirs are [[cattle]],&lt;ref&gt;{{cite journal |vauthors=Lassen B, Ståhl M, Enemark HL |title=Cryptosporidiosis - an occupational risk and a disregarded disease in Estonia. |journal=Acta Vet. Scand. |volume=56 |page=36 |date=2014  |issue=1 |doi=10.1186/1751-0147-56-36 |pmid=24902957 |pmc=4089559 |doi-access=free }}&lt;/ref&gt; [[sheep]] and [[goat]]s. In addition, in recent years, cryptosporidiosis has plagued many commercial [[leopard gecko]] breeders.  Several species of the Cryptosporidium family (C. serpentes and others) are involved, and outside of geckos it has been found in monitor lizards, iguanas and tortoises, as well as several snake species.{{citation needed|date=May 2022}}

==Notable cases==
{{Main|List of cryptosporidiosis outbreaks}}

===Before 2000===
* In 1987, 13,000 people in Carrollton, Georgia, United States, [[1987 Carroll County Cryptosporidiosis outbreak|became ill with cryptosporidiosis]]. This was the first report of its spread through a municipal water system that met all state and federal drinking water standards.&lt;ref name=&quot;sn&quot;&gt;{{Cite news |last=Fackelmann |first=K. A. |date=3 June 1989 |title=Scientists Nab Water-Polluting Parasite |work=[[Science News]] |url=https://www.sciencenews.org/archive/scientists-nab-water-polluting-parasite |access-date=21 September 2023 |via=}}&lt;/ref&gt;
* In [[Milwaukee Cryptosporidium outbreak|1993, a waterborne cryptosporidiosis outbreak]] occurred in [[Milwaukee]], Wisconsin, US. An estimated 403,000 people became ill, including 4,400 people hospitalized. The source of the Cryptosporidium is believed to be overflow from the [[Milwaukee Metropolitan Sewerage District|Milwaukee area combined sanitary and storm sewer system]] into [[Lake Michigan]], which was then taken into the Howard Avenue Water Purification Plant and distributed to an estimated 880,000 residents (of the 1.61 million residents in the [[Milwaukee metropolitan area|Milwaukee area]] who receive their drinking water from Lake Michigan).&lt;ref&gt;{{cite book | author = Botkin | author2 = Keller | name-list-style = amp | year = 2005 | title = Environmental Science, Earth as a Living Planet | edition = 5th | page = 441 }}&lt;/ref&gt; These residents, who receive their drinking water from Lake Michigan, were told to boil their water before drinking it. More people were affected in this one outbreak than the combined number of people affected in every cryptosporidiosis outbreak in the 24 years since then. An estimated 69 people died during the outbreak, according to the CDC.&lt;ref name=Corso_2003&gt;{{cite journal |vauthors=Corso P, Kramer M, Blair K, Addiss D, Davis J, Haddix A | title = Costs of Illness in the 1993 Waterborne Cryptosporidium Outbreak, Milwaukee, Wisconsin | journal = Emerg Infect Dis | volume = 9 | issue = 4 | pages = 426–31 | year = 2003 | pmid = 12702221 | pmc = 2957981 | doi = 10.3201/eid0904.020417}}&lt;/ref&gt;
* The UK's biggest outbreak occurred in [[Torbay]] in [[Devon]] in 1995.{{Citation needed|date=September 2023}}
* In the summer of 1996, ''Cryptosporidium'' affected approximately 2,000 people in [[Cranbrook, British Columbia|Cranbrook]], British Columbia, [[Canada]]. Weeks later, a separate incident occurred in [[Kelowna, British Columbia|Kelowna]], British Columbia, where 10,000 to 15,000 people got sick.&lt;ref&gt;{{cite news|title=Cryptosporidium |url=http://www.cbc.ca/news/background/health/cryptosporidium.html |newspaper=CBC News |date=23 June 2004 |access-date=19 April 2011 |archive-url=https://web.archive.org/web/20110301033629/http://www.cbc.ca/news/background/health/cryptosporidium.html |archive-date=1 March 2011 }}&lt;/ref&gt;

===2001–2009===
* In April 2001, an outbreak occurred in the city of [[North Battleford, Saskatchewan|North Battleford]], Saskatchewan, Canada. Between 5800 and 7100 people had diarrheal illness, and 1,907 cases of cryptosporidiosis were confirmed. Equipment failures at the city's antiquated water filtration plant following maintenance were found to have caused the outbreak.&lt;ref&gt;{{cite web |title = Waterborne Cryptosporidiosis Outbreak, North Battleford, Saskatchewan, Spring 2001 |publisher = Public Health Agency of Canada |date = 15 November 2001 |url = http://www.phac-aspc.gc.ca/publicat/ccdr-rmtc/01vol27/dr2722ea.html |access-date = 25 January 2008 |archive-date = 8 March 2010 |archive-url = https://web.archive.org/web/20100308071028/http://www.phac-aspc.gc.ca/publicat/ccdr-rmtc/01vol27/dr2722ea.html }}&lt;/ref&gt;
* In the summer of 2005, after numerous reports by patrons of gastrointestinal upset, a water park at [[Seneca Lake State Park]], in the [[Finger Lakes]] region of [[upstate New York]] was found to have two water storage tanks infected with ''Cryptosporidium''.  By early September 2005, over 3,800 people reported symptoms of a ''Cryptosporidium'' infection.&lt;ref&gt;{{cite web | title=State Health Department Issues Update on Seneca Lake State Park Gastrointestinal Outbreak | work=New York State Health Dept | url=http://www.health.state.ny.us/press/releases/2005/2005-09-01_school_precautions_seneca_lake_release.htm | access-date=29 September 2006 | archive-url=https://web.archive.org/web/20070311122931/http://www.health.state.ny.us/press/releases/2005/2005-09-01_school_precautions_seneca_lake_release.htm | archive-date=11 March 2007 }}&lt;/ref&gt; The &quot;Sprayground&quot; was ordered closed for the season on 15 August.{{citation needed|date=January 2023}}
* In October 2005, the [[Gwynedd]] and [[Anglesey]] areas of [[North Wales]], the United Kingdom, had an outbreak of cryptosporidiosis. The outbreak may have been linked to the drinking water supply from [[Llyn Cwellyn]], but this is not yet confirmed. As a result, 231 people fell ill, and the company [[Welsh Water]] (Dwr Cymru) advised 61,000 people to boil their water before use.
* In March 2007, a suspected outbreak occurred in [[Galway]], [[Ireland]], after the source of water for much of the county, [[Lough Corrib]], was suspected to be contaminated with the parasite. A large population (90,000 people), including areas of both Galway City and County, was advised to boil water for drinking, food preparation, and brushing teeth. On 21 March 2007, it was confirmed that the city and county's water supply was contaminated with the parasite. The area's water supply was finally approved on 20 August 2007, five months after ''Cryptosporidium'' was first detected. Around 240 people are known to have contracted the disease; experts say the true figure could be up to 5,000.&lt;ref&gt;{{Cite web |url=https://www.rte.ie/news/2007/0820/92592-galway/|title=Galway water now safer than ever - HSE|date=20 August 2007|website=RTÉ}}&lt;/ref&gt;
* Hundreds of public pools in 20 Utah counties were closed to young children in 2007, as children under 5 are most likely to spread the disease, especially children wearing [[diaper]]s. As of 10 September 2007, the [[Utah Department of Health]] had reported [http://health.utah.gov/uthealthnews/2007/20070911-Restrictions.htm 1302 cases] {{Webarchive|url=https://web.archive.org/web/20070925163236/http://health.utah.gov/uthealthnews/2007/20070911-Restrictions.htm |date=25 September 2007 }} of cryptosporidiosis in the year; a more usual number would be 30. On 25 September, the pools were reopened to those not requiring diapers, but hyperchlorination requirements were not lifted.
* On 21 September 2007, a ''Cryptosporidium'' [[outbreak]] attacked the [[Western United States]]: 230 [[Idaho]] residents, with hundreds across the [[Rocky Mountain]] area; in the [[Boise]] and [[Meridian, Idaho|Meridian]] areas; [[Utah]], 1,600 [[illnesses]]; [[Colorado]] and other Western [[U.S. state|states]] — [[Montana]], decrease.&lt;ref&gt;{{Cite web|url=https://news.yahoo.com/s/ap/20070921/ap_on_he_me/crypto_outbreak;_ylt=Ajt3IgBUbvpzpZeQjE_4Jpus0NUE |website=Yahoo.com|title=Cryptosporidium outbreak hits the West}}&lt;/ref&gt;
* On 25 June 2008, ''Cryptosporidium'' was found in England in water supplies in [[Northampton]], [[Daventry]], and some surrounding areas supplied from the [[Pitsford]] Reservoir, as reported on the [https://news.bbc.co.uk/2/hi/uk_news/england/northamptonshire/7472619.stm BBC]. People in the affected areas were warned not to drink tap water unless it had been boiled. [[Anglian Water]] confirmed that 108,000 households were affected, about 250,000 people. They advised that water might not be fit for human consumption for many weeks.&lt;ref&gt;{{Cite web|url=http://www.northamptonchron.co.uk/news/features/people-in-northampton-and-daventry-warned-not-to-drink-tap-water-1-928232|archive-date=2012-09-06 |archive-url=https://archive.today/20120906082431/http://www.northamptonchron.co.uk/news/features/people-in-northampton-and-daventry-warned-not-to-drink-tap-water-1-928232 |title=People in Northampton and Daventry warned not to drink tap water |website=Northampton Chronicle and Echo}}&lt;/ref&gt; The boil notice was lifted for all the affected customers on 4 July 2008.&lt;ref&gt;{{Cite web |url=http://www.anglianwater.co.uk/index.php?contentid=1135&amp;sectionid=135&amp;parentid=0 |title=Anglian Water-lifting of boil notice |access-date=5 July 2008 |archive-url=https://web.archive.org/web/20080801193456/http://www.anglianwater.co.uk/index.php?contentid=1135&amp;sectionid=135&amp;parentid=0 |archive-date=1 August 2008 }}&lt;/ref&gt;
* Throughout the [[summer]] of 2008; many public swimming areas, water parks, and public pools in the [[Dallas/Fort Worth Metroplex]] of [[Texas]] had an outbreak of cryptosporidiosis. [[Burger's Lake]] in [[Fort Worth, Texas|Fort Worth]] was the first to report such an outbreak. This prompted some, if not all, city-owned and private pools to close and hyperchlorinate. To the 13 August 2008, there were 400 reported cases of ''Cryptosporidium''.&lt;ref&gt;[http://www.wfaa.com/sharedcontent/dws/wfaa/latestnews/stories/wfaa080813_lj_stjames.42d762e2.html Crypto spreads to private pools] {{Webarchive |url=https://web.archive.org/web/20080814102551/http://www.wfaa.com/sharedcontent/dws/wfaa/latestnews/stories/wfaa080813_lj_stjames.42d762e2.html |date=14 August 2008 }} — [[WFAA-TV]]. Retrieved 13 August 2008.&lt;/ref&gt;
* In September 2008, a gym in [[Cambridge]], the United Kingdom, was forced to close its swimming pool until further notice after health inspectors found an outbreak of cryptosporidiosis. Environmental Health authorities requested that the water be tested after it was confirmed that a young man had been infected.&lt;ref&gt;{{Cite web|url=http://www.cambridge-news.co.uk/cn_news_cambridge/DisplayArticle.asp?ID=350905|archive-url=https://archive.today/20120721022908/http://www.cambridge-news.co.uk/cn_news_cambridge/DisplayArticle.asp?ID=350905|archive-date=21 July 2012|title=Gym closes pool in danger bug alert}}&lt;/ref&gt;

===2010 and later===
* In May 2010, the Behana creek water supply south of [[Cairns]], Australia, was found to be contaminated by cryptosporidium.&lt;ref&gt;{{cite news |title=Woree, Gordonvale residents advised to boil drinking water |first=Jessica |last=Mawer |url=http://www.abc.net.au/news/stories/2010/05/20/2904825.htm |archive-url=https://web.archive.org/web/20101117144253/http://www.abc.net.au/news/stories/2010/05/20/2904825.htm |archive-date=17 November 2010 |newspaper=ABC Online |date=20 May 2010 |access-date=19 April 2011}}&lt;/ref&gt;
* In July 2010, a local sports center in [[Cumbernauld]] (east of Glasgow, UK) detected traces of cryptosporidium in its swimming pools, causing a temporary closure of the swimming pools.{{citation needed|date=January 2023}}
* In November 2010, over 4000 cases of cryptosporidiosis were reported in [[Östersund]], Sweden. The source of contamination was the tap water.&lt;ref&gt;{{cite web |url=http://www.smittskyddsinstitutet.se/nyhetsarkiv/2010/smittskyddsinstitutets-arbete-med-det-vattenburna-utbrottet-av-cryptosporidium-i-ostersund/ |title=Smittskyddsinstitutets arbete med det vattenburna utbrottet av Cryptosporidium i Östersund |publisher=Smittskyddsinstitutet |language=sv |access-date=19 April 2011 |archive-url=https://web.archive.org/web/20110515122146/http://www.smittskyddsinstitutet.se/nyhetsarkiv/2010/smittskyddsinstitutets-arbete-med-det-vattenburna-utbrottet-av-cryptosporidium-i-ostersund/ |archive-date=15 May 2011 }}&lt;/ref&gt; In mid December 2010 the number of reported cases was 12,400 according to local media.&lt;ref&gt;{{cite news |title=Kommunens parasitenkät avslutas |first=Patrick |last=Sjöö |url=http://op.se/ostersund/1.2575643-kommunens-parasitenkat-avslutas |newspaper=Östersunds-Posten |date=13 December 2010 |language=sv |access-date=19 April 2011 |archive-date=19 July 2011 |archive-url=https://web.archive.org/web/20110719082020/http://op.se/ostersund/1.2575643-kommunens-parasitenkat-avslutas }}&lt;/ref&gt;
* As of April 2011, there has been an ongoing outbreak{{Update inline|date=November 2024}} in [[Skellefteå]], Sweden. Although many people have been diagnosed with cryptosporidiosis, the source of the parasite has not yet been found. Several tests have been taken around the water treatment unit &quot;Abborren&quot;, but so far, no results have turned up positive. Residents are being advised to boil the tap water as they continue to search for the contaminating source.{{Citation needed|date=November 2024}}
* Since May 2011, there has been an ongoing outbreak{{Update inline|date=November 2024}} in South Roscommon in Ireland. Although many people have been diagnosed with cryptosporidiosis, the source of the parasite has not yet been found. Testing continues, and the Roscommon County Council is now considering introducing Ultraviolet Filtration to their water treatment process in the next 12 months. Residents are being advised to boil the tap water, and there is no sign of this boil notice being lifted in the near future.{{Citation needed|date=November 2024}}
* In May 2013, in [[Roscommon]], Ireland, another outbreak of cryptosporidiosis was reported, and a boil water notice was issued. This was the second time the parasite was detected in a month in the Roscommon water supply. The source of one of the outbreaks had been linked to the agricultural community.&lt;ref&gt;{{cite news |title=Boil water notice after Cryptosporidiosis outbreak in Co Roscommon |url=http://www.rte.ie/news/2013/0515/450466-cryptosporidiosis-roscommon/ |date=15 May 2013 | work=RTÉ News}}&lt;/ref&gt; At least 13 people were treated for Cryptosporidiosis.&lt;ref&gt;{{cite news |title=13 people treated following Roscommon water pollution |url=http://www.rte.ie/news/2013/0517/450919-water-roscommon/ |date=17 May 2013 | work=RTÉ News}}&lt;/ref&gt;
* In September 2023, in [[Queenstown, New Zealand|Queenstown]], New Zealand, there was an [[Queenstown cryptosporidiosis outbreak|outbreak]] reported, and a boil water notice was issued a day after it was discovered. A link has been made to possible human fecal contamination. More than 60 people were treated for Cryptosporidiosis.&lt;ref&gt;{{Cite web |date=2023-10-06 |title=Human faecal contamination of Queenstown water supply most likely cause of cryptosporidium outbreak |url=https://www.rnz.co.nz/news/national/499577/human-faecal-contamination-of-queenstown-water-supply-most-likely-cause-of-cryptosporidium-outbreak |access-date=2023-10-06 |website=[[RNZ]] |language=en-nz}}&lt;/ref&gt;
* In May 2024, in Devon, United Kingdom, there was an outbreak reported, and South West Water had to issue a boil notice to 16,000 households and businesses in Brixham, Boohay, Kingswear, Roseland, and North West Paignton.  The suspected cause of the issue may be a damaged air valve, which may have allowed animal waste or contaminated groundwater to enter the water supply. Further testing is being sought to rule out any further causations.{{Citation needed|date=November 2024}}

==References==
{{Reflist}}
* {{cite book |author=White, A. Clinton Jr. |chapter=Cryptosporidiosis |editor=Mandell, G |title=Principles and Practice of Infectious Diseases |publisher=[[Elsevier]] |year=2005 |pages=3215–28 |edition=6th|display-editors=etal}}
* {{cite web |last = Upton |first = Steve J. |title = Basic Biology of ''Cryptosporidium'' |publisher = Kansas State University: Parasitology Laboratory |date = 12 September 2003 |url = http://www.k-state.edu/parasitology/basicbio |format = Website }}
* {{cite web |author = S.J. Brands (Compiler) |title = The Taxonomicon &amp; Systema Naturae |work = Taxon: Genus Cryptosporidium |publisher = Universal Taxonomic Services, Amsterdam, the Netherlands |year = 2000 |url = http://www.taxonomy.nl/taxonomicon/TaxonTree.aspx?id=660 |format = Website database |access-date = 27 February 2009 |archive-date = 23 September 2018 |archive-url = https://web.archive.org/web/20180923105939/http://www.taxonomy.nl/taxonomicon/TaxonTree.aspx?id=660 }}
* {{cite book|author=Heymann, David|title= Control of communicable diseases manual: an official report of the American Public Health Association.|year=2015|publisher=APHA Press, the American Public Health Association |isbn= 978-0-87553-018-5}}

== External links ==
* [https://www.cdc.gov/cryptosporidium/about/index.html About ''Cryptosporidiosis'' | ''Cryptosporidium'' (&quot;Crypto&quot;)] — [[Centers for Disease Control and Prevention]]
* [http://www.aquaticsintl.com/2008/novdec/0811_infectious.html Aquatics International Article Regarding Infection via Spray Parks] {{Webarchive|url=https://web.archive.org/web/20110707155008/http://www.aquaticsintl.com/2008/novdec/0811_infectious.html |date=7 July 2011 }}
* [http://cryptoDB.org CryptoDB: The ''Cryptosporidium'' Genome Resource]
{{Medical resources
|   ICD11          = {{ICD11|1A32}}
|   ICD10          = {{ICD10|A07.2}}
|   ICD9           = {{ICD9|007.4}}
|   ICDO           =
|   OMIM           =
|   OMIM_mult      =
|   MedlinePlus    = 000617
|   eMedicineSubj  = med
|   eMedicineTopic = 484
|   DiseasesDB     = 3221
|   Scholia        = Q1359898
}}
{{Alveolata}}
{{Chromalveolate diseases}}
{{Consumer Food Safety}}

[[Category:Cryptosporidiosis| ]]
[[Category:Conoidasida]]
[[Category:Protozoal diseases]]
[[Category:Zoonoses]]
[[Category:Bovine diseases]]
[[Category:Cat diseases]]
[[Category:Immunodeficiency]]