Cryptosporidium: Difference between revisions
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'''''Cryptosporidium''''', sometimes called '''crypto''',<!--Compare analogous clinical usage, such as "strep" for [[Streptococcus]] and "staph" for [[Staphylococcus]]--> is a genus of [[apicomplexa]]n [[parasitism|parasitic]] [[alveolates]] that can cause a respiratory and [[gastrointestinal disease|gastrointestinal illness]] ([[cryptosporidiosis]]) that primarily involves [[diarrhea|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. ... 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). ... 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). ... 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. ... 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=2019-05-01|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> |
'''''Cryptosporidium''''', sometimes called '''crypto''',<!--Compare analogous clinical usage, such as "strep" for [[Streptococcus]] and "staph" for [[Staphylococcus]]--> is a genus of [[apicomplexa]]n [[parasitism|parasitic]] [[alveolates]] that can cause a respiratory and [[gastrointestinal disease|gastrointestinal illness]] ([[cryptosporidiosis]]) that primarily involves [[diarrhea|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. ... 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). ... 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). ... 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. ... 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=2019-05-01|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> |
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Treatment of gastrointestinal infection in humans involves [[management of dehydration|fluid rehydration]], electrolyte replacement, and management of any pain. {{ |
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 |last1=Leder |first1=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 may be effective in slowing the rate of diarrhea, including [[Loperamide]]. [[nitazoxanide|Nitazoxanide]] is the only drug approved for the treatment of [[cryptosporidiosis]] in immunocompetent persons <ref>{{cite journal |url=https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7611666/}}</ref><ref>{{cite journal |last1=Schneider |first1=Anne |last2=Wendt |first2=Sebastian |last3=Lübbert |first3=Christoph |last4=Trawinski |first4=Henning |title=Current pharmacotherapy of cryptosporidiosis: an update of the state-of-the-art |journal=Expert Opinion on Pharmacotherapy |date=22 November 2021 |volume=22 |issue=17 |pages=2337–2342 |doi=10.1080/14656566.2021.1957097 |url=https://www.tandfonline.com/doi/full/10.1080/14656566.2021.1957097 |language=en |issn=1465-6566}}</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. ... 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] ... Symptomatic therapy includes replacement of fluids, provision of appropriate nutrition, and treatment with antimotility agents. ... 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 [[μm]] in diameter and exhibit partial [[acid-fast]] staining. They must be differentiated from other partially acid-fast organisms including ''[[Cyclospora cayetanensis]]''. |
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== General characteristics == |
== General characteristics == |
Revision as of 19:48, 4 August 2023
Cryptosporidium | |
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Cryptosporidium muris oocysts found in human feces.
| |
Scientific classification | |
Domain: | Eukaryota |
Clade: | Diaphoretickes |
Clade: | SAR |
Clade: | Alveolata |
Phylum: | Apicomplexa |
Class: | Conoidasida |
Order: | Eucoccidiorida |
Suborder: | Eimeriorina |
Family: | Cryptosporidiidae |
Genus: | Cryptosporidium Tyzzer, 1907 |
Species | |
Cryptosporidium andersoni |
Cryptosporidium, sometimes called crypto, is a genus of
Treatment of gastrointestinal infection in humans involves
General characteristics
Cryptosporidium causes
A number of 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.[7]
Cryptosporidiosis is typically an acute, short-term infection, can be recurrent through reinfection in immunocompetent hosts, and become severe or life-threatening in immunocompromised individuals. In humans, it remains in the lower intestine and may remain for up to five weeks.[7] The parasite is transmitted by environmentally hardy cysts (oocysts) that, once ingested, exist in the small intestine and result in an infection of intestinal epithelial tissue.[7] Transmission by ingestion or inhalation of coughed on fomites is a second, less likely route of infection.[1]
The
Life cycle
Cryptosporidium has three developmental stages:
Water treatment and detection
Many
Cryptosporidium is highly resistant to chlorine disinfection;[15] but with high enough concentrations and contact time, Cryptosporidium inactivation will occur with chlorine dioxide and 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. Calgon Carbon-funded research originally discovered UV's efficacy in inactivating Cryptosporidium.[16][17]
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.[18] Most cryptosporidia are 3–6 μm in size, although some reports have described larger cells.[18]
Boiling is believed to be the safest option for water contaminated by Cryptosporidium.[19][20]
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[21]
- 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°C are reached[22]
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°C - poses very little risk as these temperatures kill pathogens and even make oocysts unviable.[23]
Like many fecal-oral pathogens, the disease can also be transmitted by contaminated food, poor hygiene or turning compost in a local
Other transmission routes include exposure to laboratory specimens.[25]
See also
- 1987 Carroll County Cryptosporidiosis outbreak
- 1993 Milwaukee Cryptosporidiosis outbreak
- 1998 Sydney water crisis
- Escherichia coli
- Giardia lamblia
References
- ^ PMID 24982322.
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. ... 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). ... 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). ... 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. ... This finding suggests that respiratory cryptosporidiosis may occur commonly in immunocompetent individuals.
- S2CID 243706992.
- ^ Leder, Karin. "Cryptosporidiosis: Treatment and Prevention". UpToDate. Retrieved 4 August 2023.
- ^ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7611666/.
{{cite journal}}
: Cite journal requires|journal=
(help); Missing or empty|title=
(help) - ISSN 1465-6566.
- ^ Cabada MM, White AC, Venugopalan P, Sureshbabu J (18 August 2015). Bronze MS (ed.). "Cryptosporidiosis Treatment & Management". Medscape. WebMD. Retrieved 8 January 2016.
Infection may improve with nutritional supplementation, particularly with regimens including zinc or glutamine. ... 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] ... Symptomatic therapy includes replacement of fluids, provision of appropriate nutrition, and treatment with antimotility agents. ... 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.
- ^ a b c d "Parasites - Cryptosporidium (also known as "Crypto")". Centers for Disease Control and Prevention. February 20, 2015.
- PMID 32167464.
- S2CID 26434820.
- PMID 15510150.
- ^ "Cryptosporidium". The Australian Society for Parasitology Inc. Retrieved 7 August 2019.
- ^ Ash, Lawrence; Orihel, Thomas (2007). Ash & Orihel's Atlas of Human Parasitology (5th ed.). American Society for Clinical Pathology Press.
- ^ "Chlorine Disinfection of Recreational Water for Cryptosporidium parvum". CDC. Retrieved 2007-05-06.
- ^ "The Interim Enhanced Surface Water Treatment Rule – What Does it Mean to You?" (PDF). USEPA. Retrieved 2007-05-06.
- PMID 2339894.
- ^ Bolton, JR, Dussert, B, Bukhari, Z, Hargy, TM, Clancy, JL (1998). "Inactivation of Cryptosporidium parvum by Medium-Pressure Ultraviolet Light in Finished Drinking Water". Proc. AWWA 1998 Annual Conference, Dallas, TX. A: 389–403.
- S2CID 87880510.
- ^ PMID 2416782.
- ^ "Boil water warning 'precaution'". BBC News. 2 September 2008.
- ^ "Boil water 'into January' warning". BBC News. 30 November 2005.
- ^ Walker MD (2018). "Reducing the risk of zoonotic infection". Conservation Land Management. 16 (2): 19–22.
- ISSN 0734-242X.
- ISSN 0734-242X.
- PMID 14573839.
- ^ ISBN 978-0-8493-9476-8.
Further reading
- White AC (2005). "Cryptosporidiosis". In Mandell G (ed.). Principles and Practice of Infectious Diseases (6th ed.). Elsevier. pp. 3215–28.
- Upton SJ (2003-09-12). "Basic Biology of Cryptosporidium" (Website). Kansas State University: Parasitology Laboratory.
- Brands SJ (2000). "The Taxonomicon & Systema Naturae". Taxon: Genus Cryptosporidium. Universal Taxonomic Services, Amsterdam, The Netherlands. Archived from the original (Website database) on 2018-09-23. Retrieved 2006-10-13.
- United States Environmental Protection Agency (March 2001). "Cryptosporidium: Drinking Water Advisory" (PDF). Retrieved 4 March 2013EPA reference: EPA-822-R-01-009
{{cite web}}
: CS1 maint: postscript (link) - World Health Organization (2009). "Risk Assessment of Cryptosporidium in Drinking Water" (PDF). Retrieved 4 March 2013WHO reference: WHO/HSE/WSH/09.04
{{cite web}}
: CS1 maint: postscript (link)