Auramine-phenol vs. modified Kinyoun's acid-fast stains for detection of coccidia parasites.

ABSTRACT

OBJECTIVE: Auramine-phenol stain was compared with Kinyoun's acid-fast stain to detect coccidia parasites in fecal samples from immunocompromised patients. The comparison was based on the number of detected cases, sensitivity, specificity, time required for the procedure, ease of use, interpretation, and cost. METHODS: A total of 112 fecal specimens were examined by conventional methods: Direct wet saline smear, iodine smear, and formol ether sedimentation technique. Duplicate smears of the fecal concentrates were stained by both procedures. RESULTS: Kinyoun's and auramine-phenol stains detected 22 and 24 positive coccidia specimens respectively. The control group (27 immunocompetent relatives) showed a high incidence of Giardia lamblia infection. Kinyoun smears were difficult to interpret, while auramine smears were extremely easy to read, thus requiring less time. Artifacts were readily recognizable. The cost of auramine-phenol reagents was much higher than Kinyoun's acid-fast stain. CONCLUSION: Although the overall ranking of both staining techniques was high, the auramine-phenol stain was a more desirable test despite its higher cost.