Usefulness of Kato-Katz and trichrome staining as diagnostic methods for parasitic infections in clinical laboratories

Abstract

Objectives: To assess the effi cacy of the Kato-Katz technique and to re-evaluate other routine procedures conducted in the Microbiology Clinical Laboratory at Sultan Qaboos University Hospital (SQUH) and to throw light on the prevalence of intestinal parasitic infections among a small group of food handlers in Muscat. Method: Faecal samples collected from food handlers were examined using fi ve parasitological techniques. Results: Out of 100 faecal samples, 53 were positive for one or more of 11 intestinal parasites. The Kato- Katz and trichrome stain methods were found superior to the other techniques in detecting helminthic and protozoan infections, respectively. The auramine stain was useful only in detecting Cryptosporidium parvum oocysts. Conclusion: A combination of trichrome stain and Kato-Katz techniques for stool examination is suffi cient and recommended for busy laboratories; auramine stain should be applied only to samples with suspected cryptosporidal infections. Key Words: Kato-Katz, wet preparation, concentration, trichrome and auramine stains, intestinal parasites, food handlers, Oman.