View source for Cryptosporidium

{{Short description|Genus of single-celled organisms}}
{{About|the protozoan|the disease|Cryptosporidiosis}}
{{Hatnote|Do not confuse Cryptosporidium (protists) with [[Cryptococcus]] (fungi).}}
{{distinguish|text = [[cryptocurrency]], also known as crypto}}
{{Use dmy dates|date=September 2023}}
{{Use American English|date=August 2024}}
{{Missing information|effects of ''Cryptosporidium'' infection on groups of animals other than mammals|date=August 2023}}
{{Automatic taxobox
| image              = Cryptosporidium muris.jpg
| image_caption      = [[Oocyst]]s of ''[[Cryptosporidium muris|C. muris]]'' found in human feces
| display_parents    = 2
| taxon              = Cryptosporidium
| authority          = Tyzzer, 1907
| subdivision_ranks  = Species
| subdivision        = See {{ Section link | | Species }}
}}

'''''Cryptosporidium''''', sometimes called '''crypto''',<!--Compare analogous clinical usage, such as "strep" for [[Streptococcus]] and "staph" for [[Staphylococcus]]--> is an [[apicomplexa]]n genus of [[alveolates]] which are [[parasitism|parasites]] that can cause a respiratory and gastrointestinal illness ([[cryptosporidiosis]]) that primarily involves watery [[diarrhea]] (intestinal cryptosporidiosis), sometimes with a persistent cough (respiratory cryptosporidiosis).<ref name="Respiratory cryptosporidiosis - fomite transmission">{{cite journal | vauthors = Sponseller JK, Griffiths JK, Tzipori S | title = The evolution of respiratory Cryptosporidiosis: evidence for transmission by inhalation | journal = Clinical Microbiology Reviews | volume = 27 | issue = 3 | pages = 575–86 | date = July 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.&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).&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).&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.&nbsp;... This finding suggests that respiratory cryptosporidiosis may occur commonly in immunocompetent individuals. }}</ref><ref>{{Cite journal|last1=Chalmers|first1=Rachel M.|last2=Davies|first2=Angharad P.|last3=Tyler|first3=Kevin|date=1 May 2019|title=Cryptosporidium|journal=Microbiology|language=en|volume=165|issue=5|pages=500–502|doi=10.1099/mic.0.000764|pmid=31268415|s2cid=243706992|issn=1350-0872|doi-access=free}}</ref>

Treatment of gastrointestinal infection in humans involves [[management of dehydration|fluid rehydration]], electrolyte replacement, and management of any pain. For cryptosporidiosis, supportive treatment and symptom management are the primary treatments for immunocompetent individuals.<ref>{{cite web |last=Leder |first=Karin |title=Cryptosporidiosis: Treatment and Prevention |url=https://www.uptodate.com/contents/cryptosporidiosis-treatment-and-prevention?search=cryptosporidium&source=search_result&selectedTitle=2~84&usage_type=default&display_rank=2 |website=UpToDate |access-date=4 August 2023}}</ref> Anti-diarrheal medication, such as [[Loperamide]], may be effective in slowing the rate of diarrhea. [[Nitazoxanide]] is the only drug approved for the treatment of [[cryptosporidiosis]] in immunocompetent persons.<ref>{{cite journal |last1=Love |first1=MS |last2=Choy |first2=RKM |title=Emerging treatment options for cryptosporidiosis. |journal=Current Opinion in Infectious Diseases |date=1 October 2021 |volume=34 |issue=5 |pages=455–462 |doi=10.1097/QCO.0000000000000761 |pmid=34261904|pmc=7611666 }}</ref> Supplemental zinc may improve symptoms,<ref name="MS Crypto treatment">{{cite web|vauthors=Cabada MM, White AC, Venugopalan P, Sureshbabu J |editor=Bronze MS|title=Cryptosporidiosis Treatment & 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.&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]&nbsp;... Symptomatic therapy includes replacement of fluids, provision of appropriate nutrition, and treatment with antimotility agents.&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.}}</ref> particularly in recurrent or persistent infections or in others at risk for [[zinc deficiency]].  ''Cryptosporidium'' oocysts are 4–6&nbsp;[[μm]] in diameter and exhibit partial [[acid-fast]] staining. They must be differentiated from other partially acid-fast organisms including ''[[Cyclospora cayetanensis]]''.

== General characteristics ==
''Cryptosporidium'' causes [[cryptosporidiosis]], an infection that may present as a [[diarrhea]], sometimes with a persistent cough in immunocompetent hosts.{{clarify|date=November 2022}}<ref name="Respiratory cryptosporidiosis - fomite transmission" /> Other [[apicomplexan]] pathogens of humans include the [[malaria]] parasite ''[[Plasmodium]]'' and the [[toxoplasmosis]] parasite ''[[Toxoplasma]]''. Unlike ''Plasmodium'', which transmits via a mosquito [[disease vector]], and ''Toxoplasma'' which needs a feline as [[definitive host]],<ref>{{cite web |title=Toxoplasmosis |url=https://www.cdc.gov/dpdx/toxoplasmosis/index.html#:~:text=The%20only%20known%20definitive%20hosts,large%20numbers%20may%20be%20shed. |website=www.cdc.gov |publisher=[[U.S. Centers for Disease Control and Prevention]] |location=Atlanta, GA |language=en-us |date=5 May 2022}}</ref> ''Cryptosporidium'' does not use a vector, and is capable of completing its lifecycle within a single host. It results in [[cyst]] stages that are excreted in feces or through inhalation of coughed on [[fomites]] and are capable of transmission to a new host.<ref name="Respiratory cryptosporidiosis - fomite transmission" /><ref name=CDC_Site>{{cite web | title = Parasites – Cryptosporidium (also known as "Crypto") | url = https://www.cdc.gov/parasites/crypto/pathogen.html | publisher = Centers for Disease Control and Prevention | date = 20 February 2015 }}</ref><ref name="WidmerCarmena2020">{{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|pages=14|issn=1776-1042|doi=10.1051/parasite/2020011 |pmid=32167464| pmc=7069357 |doi-access=free}} {{open access}}</ref>

A number of species infect mammals. In humans, the main causes of disease are ''[[Cryptosporidium parvum|C. parvum]]'' and ''[[Cryptosporidium hominis|C. hominis]]'' (previously ''C. parvum'' genotype 1). ''[[Cryptosporidium canis|C. canis]]'', ''[[Cryptosporidium felis|C. felis]]'', ''[[Cryptosporidium meleagridis|C. meleagridis]]'', and ''[[Cryptosporidium muris|C. muris]]'' can also cause disease in humans.<ref name=CDC_Site/>

Cryptosporidiosis is typically an acute, short-term infection, but can recur through reinfection in immunocompetent hosts, or become severe or life-threatening in immunocompromised individuals. In humans, it remains in the lower intestine and may remain for up to five weeks.<ref name=CDC_Site/> The parasite is transmitted by environmentally hardy [[cyst]]s (oocysts) that, once ingested, exist in the [[small intestine]] and result in an infection of intestinal [[Epithelium|epithelial tissue]].<ref name=CDC_Site/> Transmission by ingestion or inhalation of coughed-on fomites is a second, less likely route of infection.<ref name="Respiratory cryptosporidiosis - fomite transmission" />

The [[genome]] of ''C. parvum'', sequenced in 2004, was found to be unusual amongst [[eukaryote]]s in that the [[mitochondria]] seem not to [[mitochondrial DNA|contain DNA]].<ref>{{cite journal | vauthors = Abrahamsen MS, Templeton TJ, Enomoto S, Abrahante JE, Zhu G, Lancto CA, Deng M, Liu C, Widmer G, Tzipori S, Buck GA, Xu P, Bankier AT, Dear PH, Konfortov BA, Spriggs HF, Iyer L, Anantharaman V, Aravind L, Kapur V | title = Complete genome sequence of the apicomplexan, Cryptosporidium parvum | journal = Science | volume = 304 | issue = 5669 | pages = 441–5 | date = April 2004 | pmid = 15044751 | doi = 10.1126/science.1094786 | bibcode = 2004Sci...304..441A | s2cid = 26434820 }}</ref> A closely related species, ''C. hominis'', also has its genome sequence available.<ref>{{cite journal | vauthors = Xu P, Widmer G, Wang Y, Ozaki LS, Alves JM, Serrano MG, Puiu D, Manque P, Akiyoshi D, Mackey AJ, Pearson WR, Dear PH, Bankier AT, Peterson DL, Abrahamsen MS, Kapur V, Tzipori S, Buck GA | title = The genome of Cryptosporidium hominis | journal = Nature | volume = 431 | issue = 7012 | pages = 1107–12 | date = October 2004 | pmid = 15510150 | doi = 10.1038/nature02977 | bibcode = 2004Natur.431.1107X | doi-access = free }}</ref>

==Life cycle==
[[Image:Cryptosporidiosis 01.png|frameless|right|300px]]
''Cryptosporidium'' has three developmental stages: [[meronts]], [[gamonts]] and [[oocysts]].<ref>{{cite web |title=Cryptosporidium |url=https://www.parasite.org.au/para-site/text/cryptosporidium-text.html |website=The Australian Society for Parasitology Inc. |access-date=7 August 2019}}</ref> They reproduce within the intestinal [[epithelial cells]].<ref name="A&O">{{cite book |last1=Ash |first1=Lawrence |last2=Orihel |first2=Thomas |title=Ash & Orihel's Atlas of Human Parasitology |date=2007 |publisher=American Society for Clinical Pathology Press |edition=5th}}</ref>
The ''Cryptosporidium'' [[spore]] phase ([[oocyst]]) can survive for lengthy periods outside a host. It can also resist many common [[disinfectant]]s, including [[chlorine]]-based disinfectants.<ref>{{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}}</ref>

== Water treatment and detection ==
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. Direct filtration, which is typically used to treat water with low [[suspended solids|particulate]] levels, includes coagulation and filtration but not sedimentation. Other common filtration processes including [[slow sand filter]]s,  [[Diatomaceous earth#Filtration|diatomaceous earth filters]], and membranes will remove 99% of ''Cryptosporidium''.<ref>{{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}}</ref> Membranes and bag- and cartridge-filter products remove ''Cryptosporidium'' specifically.

''Cryptosporidium'' is highly resistant to chlorine disinfection;<ref>{{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 = Applied and Environmental Microbiology | 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 | url = }}</ref> but with high enough concentrations and contact time, ''Cryptosporidium'' inactivation will occur with [[Chlorine dioxide#Water treatment|chlorine dioxide]] and [[Ozone#Applications 2|ozone]] treatment. In general, the required levels of chlorine 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''.<ref>{{cite journal | vauthors = Bolton, JR, Dussert, B, Bukhari, Z, Hargy, TM, Clancy, JL | title = Inactivation of Cryptosporidium parvum by Medium-Pressure Ultraviolet Light in Finished Drinking Water | journal = Proc. AWWA 1998 Annual Conference, Dallas, TX | volume = A | pages = 389–403 | year = 1998 }}</ref><ref>{{cite journal | vauthors = Bukhari Z, Hargy TM, Bolton JR, Dussert B, Clancy JL | title = Medium Pressure UV Light for Oocyst Inactivation | journal = Journal of the American Water Works Association | volume = 91 | issue = 3 | pages = 86–94 | year = 1999 | doi = 10.1002/j.1551-8833.1999.tb08602.x | s2cid = 87880510 }}</ref>

One of the largest challenges in identifying outbreaks is the ability to verify the results in a [[laboratory]].  The oocytes may be seen by microscopic examination of a stool sample, but they may be confused with other objects or artifacts similar in appearance.<ref name=Lab_Dx>{{cite journal | vauthors = Casemore DP, Armstrong M, Sands RL | title = Laboratory diagnosis of cryptosporidiosis | journal = Journal of Clinical Pathology | volume = 38 | issue = 12 | pages = 1337–41 | date = December 1985 | pmid = 2416782 | pmc = 499488 | doi = 10.1136/jcp.38.12.1337 }}</ref> Most cryptosporidia are 3–6 μm in size, although some reports have described larger cells.<ref name=Lab_Dx />

Boiling is believed to be the safest option for water contaminated by ''Cryptosporidium''.<ref>{{cite web | title = Boil water warning 'precaution' | url = http://news.bbc.co.uk/1/hi/wales/7589839.stm | work = BBC News | date =  2 September 2008 }}</ref><ref>{{cite web | title = Boil water 'into January' warning | url = http://news.bbc.co.uk/1/hi/wales/4484946.stm | work = BBC News | date = 30 November 2005 }}</ref><ref>{{Cite web |date=2024-05-15 |title=Devon residents urged to boil water after parasite found |url=https://www.bbc.com/news/articles/cd1q1d51w27o |access-date=2024-05-16 |website=BBC News |language=en-GB}}</ref>

== Epidemiology ==
=== Exposure risks ===
* People who swim regularly in pools with insufficient sanitation (certain strains of ''Cryptosporidium'' are chlorine-resistant)
* Child-care workers
* Parents of infected children
* People caring for other people with cryptosporidiosis
* Backpackers, hikers, and campers who drink unfiltered, untreated water
* People who visit petting farms and open farms with public access<ref>{{cite journal | vauthors = Walker MD | year = 2018 | title = Reducing the risk of zoonotic infection | journal = Conservation Land Management | volume = 16 | issue = 2 | pages = 19–22 | url = https://sites.google.com/site/cryptosporidiosisukanimal/ | access-date = 14 July 2018 | archive-date = 25 October 2020 | archive-url = https://web.archive.org/web/20201025155410/https://sites.google.com/site/cryptosporidiosisukanimal/ | url-status = dead }}</ref>
* People, including swimmers, who swallow water from contaminated sources
* People handling infected cattle
* People exposed to human feces
* People who turn [[compost]] that has not gone through its phase where temperatures over 50&nbsp;°C are reached<ref name="sciencedirect.com">{{Cite journal|date=1 August 1995|title=Occurrence of enteric pathogens in composted domestic solid waste containing disposable diapers|url=https://www.sciencedirect.com/science/article/abs/pii/S0734242X95900810|journal=Waste Management & Research|language=en|volume=13|issue=4|pages=315–324|doi=10.1016/S0734-242X(95)90081-0|issn=0734-242X|last1=Gerba|first1=C.|bibcode=1995WMR....13..315G }}</ref>

Dealing with stabilized compost - i.e. composting material that has gone through the phases where micro-organisms are digesting the organic matter and the temperature inside the composting pile has reached temperature up to 50–70&nbsp;°C – poses very little risk as these temperatures kill pathogens and even make oocysts unviable.<ref name="sciencedirect.com"/>

Like many fecal-oral pathogens, the disease can also be transmitted by contaminated food, poor hygiene or turning compost in a local [[compost]] site.  Testing of water, as well as [[epidemiological]] study, are necessary to determine the sources of specific infections. ''Cryptosporidium'' typically does not cause serious illness in healthy people. It may chronically sicken some children, as well as adults exposed and [[immunocompromised]].

== Species ==
* ''[[Cryptosporidium andersoni]]''
* ''[[Cryptosporidium bailey]]''
* ''[[Cryptosporidium bovis]]''
* ''[[Cryptosporidium cervine]]''
* ''[[Cryptosporidium canis]]''
* ''[[Cryptosporidium cuniculus]]''
* ''[[Cryptosporidium ducismarci]]''
* ''[[Cryptosporidium fayeri]]''
* ''[[Cryptosporidium felis]]''
* ''[[Cryptosporidium fragile]]''
* ''[[Cryptosporidium galli]]''
* ''[[Cryptosporidium hominis]]''
* ''[[Cryptosporidium marcopodum]]''
* ''[[Cryptosporidium meleagridis]]''
* ''[[Cryptosporidium molnari]]''
* ''[[Cryptosporidium muris]]''
* ''[[Cryptosporidium parvum]]''
* ''[[Cryptosporidium ryanae]]''
* ''[[Cryptosporidium saurophilum]]''
* ''[[Cryptosporidium serpentis]]''
* ''[[Cryptosporidium suis]]''
* ''[[Cryptosporidium ubiquitum]]''
* ''[[Cryptosporidium viatorum]]''
* ''[[Cryptosporidium wrairi]]''
* ''[[Cryptosporidium xiaoi]]''

== See also ==
* [[1987 Carroll County Cryptosporidiosis outbreak]]
* [[1993 Milwaukee Cryptosporidiosis outbreak]]
* [[1998 Sydney water crisis]]
* ''[[Escherichia coli]]''
* ''[[Giardia lamblia]]''

== References ==
{{Reflist}}

== Further reading ==
{{Refbegin}}
* {{cite book | last = White | first = A. Clinton | chapter = Cryptosporidiosis | veditors = Mandell G | title = Principles and Practice of Infectious Diseases | edition = 6th | publisher = Elsevier | date = 2005 | pages = 3215–28 }}
* {{cite web
  | last = Upton
  | first = Steve J.
  | name-list-style = vanc
  | title = Basic Biology of ''Cryptosporidium''
  | publisher = Kansas State University: Parasitology Laboratory
  | date = 12 September 2003
  | url = http://www.k-state.edu/parasitology/basicbio
  }}
* {{cite web
  | vauthors = Brands SJ
  | title = The Taxonomicon & 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
  | access-date = 13 October 2006
  | archive-date = 23 September 2018
  | archive-url = https://web.archive.org/web/20180923105939/http://www.taxonomy.nl/taxonomicon/TaxonTree.aspx?id=660
  | url-status = dead
  }}
* {{Cite web
  |date=March 2001
  |author=United States Environmental Protection Agency
  |title=Cryptosporidium: Drinking Water Advisory
  |url=http://water.epa.gov/action/advisories/drinking/upload/2009_02_03_criteria_humanhealth_microbial_cryptoha.pdf
  |access-date=4 March 2013
|author-link=United States Environmental Protection Agency
|id=EPA-822-R-01-009
  }}
* {{Cite web
  |year=2009
  |author=World Health Organization
  |title=Risk Assessment of Cryptosporidium in Drinking Water
  |url=http://whqlibdoc.who.int/hq/2009/WHO_HSE_WSH_09.04_eng.pdf
  |access-date=4 March 2013
|author-link=World Health Organization
|id=WHO/HSE/WSH/09.04
  }}
{{Refend}}

== External links ==
{{Commons category}}
* [http://cryptoDB.org CryptoDB: The ''Cryptosporidium'' Genome Resource]

{{Eukaryota classification}}
{{Alveolata}}
{{Portal bar|Biology}}
{{Taxonbar|from=Q133078}}
{{Authority control}}

[[Category:Apicomplexa genera]]
[[Category:Conoidasida]]