Diagnosis of intestinal microsporidiosis in pediatric oncology patients in Egypt using modified acid fast trichrome staining versus PCR

AbstractMicrosporidia are intracellular opportunistic parasites that cause chronic diarrhea in AIDS patients. Little is known about the prevalence of these pathogens in pediatric cases with cancer and diarrhea. Unidentified causes of chronic diarrhea were previously encountered in pediatric cancer patients at the National Cancer Institute in Egypt. Therefore, this study tried to search for the contribution of microsporidia as a causative agent of diarrhea in this population using acid-fast trichrome stain as a specific staining and the PCR in order to evaluate the staining technique in clinical diagnosis of microsporidia. Between January 2008 and June 2009, 271 diarrheic samples from pediatric patients with cancer were studied. Microsporidia were confirmed in 13 (4.8%) cases by both PCR and staining, and additional 2 samples were positive only by staining. As a negative control, stool samples from 60 diarrheic children without malignant cancer and no microsporidia detection were examined by these two methods. So, it can be concluded that adding a diagnostic test for microsporidia to the clinical laboratory work in hospitals concerned with cancer is essential. Acid fast trichrome staining technique as being nearly efficacious as the PCR, but simpler and less expensive, can replace the molecular techniques for the diagnosis of microsporidia.