Comments
INITIAL SYMPTOMS:
Diarrhea lasting more than two weeks; Eosinophilia is associated with the related Isospora and Sarcocystis infections.
FINDINGS:
Cyclospora infections cause prolonged, watery diarrhea, fatigue, and weight loss. Fever is rare. Diarrhea usually lasts for 10-24 days in untreated, immunocompetent patients. Complications include Guillain-Barre syndrome and Reiter's syndrome. [CCDM, p. 139] "Does not cause fever, inflammatory diarrhea or eosinophilia." Associated with reactive arthritis in prolonged infections; [ABX Guide] Symptoms include noninflammatory diarrhea, fatigue, weight loss, abdominal pain, nausea, and sometimes constipation. The average incubation period is one week. Diagnosis by identification of oocysts in fecal smears is difficult and requires the skills of an experienced technician. [Soave R, Herwaldt BL, Relman DA. Cyclospora. Infect Dis Clin North Am. 1998 Mar;12(1):1-12] An outbreak of more than 400 cases linked to prepackaged lettuce from Mexico and sold to restaurants in Nebraska and Iowa occurred in June and July 2013. [CDC: Investigation of an Outbreak of Cyclosporiasis in the United States] Reported complications are biliary tract disease (AIDS patients), reactive arthritis, and Guillain-Barre syndrome. [PPID, p. 3185]
EPIDEMIOLOGY:
Outbreaks in North America have been linked to produce (raspberries, basil, and lettuce) imported from developing countries. [CCDM, p. 140]
RELATED INFECTIONS:
The three important human intestinal coccidial protozoa are Cryptosporidium, Cyclospora, and Isospora. They are resistant to chlorine disinfection and cause identical symptoms. The Cryptosporidium cysts are smaller and more difficult to remove by filtering. The cysts of Cyclospora and Isospora, unlike those of Cryptosporidium, are not infectious when passed in the feces. They require days to weeks in the environment to sporulate. Isospora is rarely found outside tropical and subtropical regions. Isospora, and possibly Dientamoeba fragilis, are the only protozoans known to cause eosinophilia. [Guerrant, p. 641-4, 940] Isospora belli was renamed Cystoisospora belli. Findings are fever, abdominal pain, and watery diarrhea (no blood), and eosinophilia. Chronic infection in AIDS patients may resemble cryptosporidiosis. [Harrison ID, p. 1210] Sarcocystosis is a similar disease caused by Sarcocystis spp. Most infections are asymptomatic, but gastroenteritis can occur. Humans are infected after eating poorly cooked beef or pork. In addition to diarrhea and abdominal pain, humans can also develop intramuscular cysts, myalgias, and eosinophilia. [Guerrant, p. 644-5]
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