Cyclosporiasis overview: Difference between revisions
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==Overview== | ==Overview== | ||
Cyclosporiasis is an intestinal illness caused by the [[protozoan]] [[Cyclospora cayetanensis]], which is transmitted by [[feces]] or feces-contaminated fresh produce and water. [[Outbreak]]s have been reported in imported raspberries. Fortunately it is not spread from person to person. It is commonly the cause of [[diarrhea]] for many travelers. | Cyclosporiasis is an intestinal illness caused by the [[protozoan]] [[Cyclospora cayetanensis]], which is transmitted by [[feces]] or feces-contaminated fresh produce and water. [[Outbreak]]s have been reported in imported raspberries. Fortunately it is not spread from person to person. It is commonly the cause of [[diarrhea]] for many travelers. | ||
==Pathophysiology== | |||
When freshly passed in stools, the oocyst is not infective (thus, direct fecal-oral transmission cannot occur; this differentiates Cyclospora from another important coccidian parasite, Cryptosporidium). In the environment, sporulation occurs after days or weeks at temperatures between 22°C to 32°C, resulting in division of the sporont into two sporocysts, each containing two elongate sporozoites. Fresh produce and water can serve as vehicles for transmission and the sporulated oocysts are ingested (in contaminated food or water). The oocysts excyst in the gastrointestinal tract, freeing the sporozoites which invade the epithelial cells of the small intestine. Inside the cells they undergo asexual multiplication and sexual development to mature into oocysts, which will be shed in stools. The potential mechanisms of contamination of food and water are still under investigation. | |||
==Causes== | ==Causes== | ||
[[Cyclospora cayetanensis]] has been only recently identified as a single-celled coccidian parasite. The species designation was given in 1994 to Peruvian isolates of human-associated Cyclospora. It appears that all human cases are caused by this species. | [[Cyclospora cayetanensis]] has been only recently identified as a single-celled coccidian parasite. The species designation was given in 1994 to Peruvian isolates of human-associated Cyclospora. It appears that all human cases are caused by this species. | ||
==Differential Diagnosis== | |||
Cyclosporiasis must be differentiated from other infectious causes of watery [[diarrhea]]. | |||
==Epidemiology and Demographics== | ==Epidemiology and Demographics== | ||
Cyclosporiasis occurs in many countries, but the disease seems to be most common in tropical and subtropical regions. In areas where cyclosporiasis has been studied, the risk for infection is seasonal. However, no consistent pattern with respect to environmental conditions such as temperature or rainfall has been identified. | Cyclosporiasis occurs in many countries, but the disease seems to be most common in tropical and subtropical regions. In areas where cyclosporiasis has been studied, the risk for infection is seasonal. However, no consistent pattern with respect to environmental conditions such as temperature or rainfall has been identified. | ||
==Risk Factors== | ==Risk Factors== | ||
People of all ages are at risk for infection. Persons living or traveling in tropical or subtropical regions may be at increased risk because cyclosporiasis is [[endemic]] (found) in some developing countries. Foodborne outbreaks of cyclosporiasis in the United States and Canada have been linked to various types of imported fresh produce. | People of all ages are at risk for infection. Persons living or traveling in tropical or subtropical regions may be at increased risk because cyclosporiasis is [[endemic]] (found) in some developing countries. Foodborne outbreaks of cyclosporiasis in the United States and Canada have been linked to various types of imported fresh produce. | ||
==Natural History, Prognosis and Complications== | |||
The symptoms usually start within one week of ingestion of contaminated food and water. If left untreated, symptoms may persist for weeks and months. This infection is not life threatening and is rarely associated with complications. People living in endemic area might have asymptomatic infections. | |||
==References == | ==References == | ||
Revision as of 22:14, 22 July 2013
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Cyclosporiasis Microchapters |
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Case Studies |
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Cyclosporiasis overview On the Web |
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American Roentgen Ray Society Images of Cyclosporiasis overview |
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Risk calculators and risk factors for Cyclosporiasis overview |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Kalsang Dolma, M.B.B.S.[2]
Overview
Cyclosporiasis is an intestinal illness caused by the protozoan Cyclospora cayetanensis, which is transmitted by feces or feces-contaminated fresh produce and water. Outbreaks have been reported in imported raspberries. Fortunately it is not spread from person to person. It is commonly the cause of diarrhea for many travelers.
Pathophysiology
When freshly passed in stools, the oocyst is not infective (thus, direct fecal-oral transmission cannot occur; this differentiates Cyclospora from another important coccidian parasite, Cryptosporidium). In the environment, sporulation occurs after days or weeks at temperatures between 22°C to 32°C, resulting in division of the sporont into two sporocysts, each containing two elongate sporozoites. Fresh produce and water can serve as vehicles for transmission and the sporulated oocysts are ingested (in contaminated food or water). The oocysts excyst in the gastrointestinal tract, freeing the sporozoites which invade the epithelial cells of the small intestine. Inside the cells they undergo asexual multiplication and sexual development to mature into oocysts, which will be shed in stools. The potential mechanisms of contamination of food and water are still under investigation.
Causes
Cyclospora cayetanensis has been only recently identified as a single-celled coccidian parasite. The species designation was given in 1994 to Peruvian isolates of human-associated Cyclospora. It appears that all human cases are caused by this species.
Differential Diagnosis
Cyclosporiasis must be differentiated from other infectious causes of watery diarrhea.
Epidemiology and Demographics
Cyclosporiasis occurs in many countries, but the disease seems to be most common in tropical and subtropical regions. In areas where cyclosporiasis has been studied, the risk for infection is seasonal. However, no consistent pattern with respect to environmental conditions such as temperature or rainfall has been identified.
Risk Factors
People of all ages are at risk for infection. Persons living or traveling in tropical or subtropical regions may be at increased risk because cyclosporiasis is endemic (found) in some developing countries. Foodborne outbreaks of cyclosporiasis in the United States and Canada have been linked to various types of imported fresh produce.
Natural History, Prognosis and Complications
The symptoms usually start within one week of ingestion of contaminated food and water. If left untreated, symptoms may persist for weeks and months. This infection is not life threatening and is rarely associated with complications. People living in endemic area might have asymptomatic infections.