Coccidians

Cryptosporidium parvum. Oocysts in fecal smear (wet mount, high power). Two oocysts are present in this unstained wet mount preparation. Although oocysts are refractile, often they are difficult to detect amidst debris. They typically contain the dark granules seen here; they vary in number from one to six. These oocysts measure 4 to 6 µm and must be differentiated from the larger oocysts of Cyclospora cayetanensis (8 to 10 µm) and from yeasts that are similar in size and frequently occur in feces.