Cyclospora cayetanensis, a coccidian protozoan parasite.
Ingestion of infective Cyclospora oocysts, such as in contaminated food or water.
Most common in tropical and subtropical regions where outbreaks are frequently seasonal (such as during summers and rainy season in Nepal). Outbreaks in the United States and Canada have been linked to imported fresh produce.
Incubation period averages 1 week (range, 2 days to >2 weeks). Onset of symptoms is often abrupt but can be gradual; some people have an influenzalike prodrome. The most common symptom is watery diarrhea, which can be profuse. Other symptoms can include anorexia, weight loss, abdominal cramps, bloating, nausea, body aches, vomiting, and low-grade fever.
Diagnosed by detecting Cyclospora oocysts in stool specimens. Stool examinations for ova and parasites usually do not include methods for detecting Cyclospora, so clinicians should specifically request Cyclospora testing. Diagnostic assistance is also available from CDC (www.dpd.cdc.gov/dpdx, 404-718-4745; email@example.com).
Trimethoprim-sulfamethoxazole; no highly effective alternatives have been identified.