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

Objectives: To assess the efficacy 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 five 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 Cryptosporidiumparvum oocysts. Conclusion: A combination of trichrome stain and Kato-Katz techniques for stool examination is sufficient and recommended for busy laboratories; auramine stain should be applied only to samples with suspected cryptosporidal infections.