Positive stool Cyclospora cayetanensis oocyst test 2026-08-10T05:20:25Z Detection of Cyclospora cayetanensis oocysts in a stool specimen by microscopy. Cyclospora cayetanensis is a coccidian protozoan parasite of the human small intestine. The transmission stage of Cyclospora, known as an oocyst, is spherical and 8 to 10 micrometers in diameter. Unsporulated oocysts are shed into the environment with the feces of infected individuals. Oocysts undergo sporulation, becoming infective within a few days or weeks, depending upon environmental conditions. Infection may result when sporulated oocysts are ingested, primarily through contaminated water or food. Diagnosis usually involves microscopic examination of stool specimens for the presence of oocysts. Positive stool infectious agent test