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Cyclosporiasis (Cyclospora cayetanensis)
1996 Case Definition

Clinical Description

An illness of variable severity caused by the protozoan Cyclospora cayetanensis and commonly characterized by watery diarrhea, loss of appetite, weight loss, abdominal bloating and cramping, increased flatus, nausea, fatigue, and low-grade fever. Vomiting also may be noted. Relapses and asymptomatic infections can occur.

Laboratory Criteria for Diagnosis

Demonstration of Cyclospora oocysts (by morphologic criteria or by demonstration of sporulation) or Cyclospora DNA (by polymerase chain reaction) in stool, duodenal/jejunal aspirates or small-bowel biopsy specimens

Case Classification


A clinically compatible case that is epidemiologically linked to a confirmed case


A case that is laboratory confirmed


Direct person-to-person transmission is unlikely because Cyclospora oocysts are not infectious at the time of excretion.