UNIFORM STAINING OF CYCLOSPORA OOCYSTS IN FECAL SMEARS BY A MODIFIED SAFRANIN TECHNIQUE WITH MICROWAVE-HEATING

Cyclospora, a coccidian protist, is increasingly being identified as a n important, newly emerging parasite that causes diarrhea, flatulence, fatigue, and abdominal pain leading to weight loss in immunocompetent persons with or without a recent travel history as well as in patient s with AIDS. Modified Kinyoun's acid-fast stain is the most commonly u sed stain to identify the oocyst of this parasite in fecal smears. Ooc ysts of Cyclospora stain variably by the modified acid-fast procedure, resulting in the possible misidentification of this parasite. We exam ined fecal smears stained by six different procedures that included Gi emsa,trichrome, chromotrope, Gram-chromotrope, acid-fast, and safranin stains, We report on a safranin-based stain that uniformly stains ooc ysts of Cyclospora a brilliant reddish orange, provided that the fecal smears are heated in a microwave oven prior to staining, This stainin g procedure, besides being superior to acid fast staining, is fast, re liable, and easy to perform in most clinical laboratories.