Evaluation Of Microscopic Staining Techniques For The Diagnosis Of Opportunistic Protozoan Infections In A Developing Country
A Fagbenro- Beyioku, W Oyibo, E Onuoha, C Ukaegbu, O Ojuromi
acid fast carbol fuchsin stain, coccidian opportunistic parasites, cryptosporidium, microsporidium, permanent coccidian stains, trichrome stain
A Fagbenro- Beyioku, W Oyibo, E Onuoha, C Ukaegbu, O Ojuromi. Evaluation Of Microscopic Staining Techniques For The Diagnosis Of Opportunistic Protozoan Infections In A Developing Country. The Internet Journal of Tropical Medicine. 2006 Volume 3 Number 2.
Trichome staining method was superior to other techniques in detecting opportunistic protozoan infections: 35.7% for Cryptosporidium sp, and 50% for Microsporidium sp. The Acid Fast (Carbol Fuchsin) stain was useful only in detecting the oocysts of Cryptosporidium sp.. With 35.7% positivity. Laboratories in developing countries can put Tricrome stain in their priority purchase.
The prevalence of intestinal parasites has been studied extensively in both rural and urban areas of Nigeria 1,2,3. Routine diagnosis of intestinal parasitic infections is usually performed by a simple smear in normal saline or iodine stain solution using light microscopy4. More recently, some unusual protozoans such as
70 diarrhoeal stool samples (each pooled from three consecutive days) obtained from various patients, including HIV/AIDS patients who were attending various clinics in Lagos, Nigeria were processed for routine microscopic examinations of ova and parasites. Saline and Iodine wet mount, and permanent slides of Giemsa, Carbol Fuchsin (Kinyoun-modified acid fast) and Weber's modified Trichrome stains were also made. Faecal smears on slides and formal-ether concentration methods were prepared for each stool samples using standard procedures 9,10. The micrometer was used for the accurate measurement of oocysts, cysts, and ova that were seen. The 100X oil immersion lens was employed in all cases to demonstrate the morphology of oocysts. Informed consent was obtained from selected patients after explaining the aim of the study. These patients were already enrolled in an on-going HIV/AIDS clinics and treatment programme.
Intestinal opportunistic protozoans, particularly
In this study, Weber's modified Trichome stain using chromotrope 2R and phosphotungstic acid clearly differentiated the spores of microsporidium in 50% and 35.7% of oocysts of Cryptosporidium of the positive samples (Table). Carbol fuchsin stains, on the other hand, diagnosed 35.7% of the oocysts of
Weber's Trichome staining techniques could be prioritized in the purchase of stains for the diagnosis of
Trichrome stain is adequate to diagnose coccidian opportunistic parasites in developing countries where resource is constrained and should be considered by laboratories operating a tight budget
Dr. Wellington A. Oyibo. Consultant Medical Parasitologist Department of Medical Microbiology and Parasitology, College of Medicine, University of Lagos, Lagos, Nigeria. TEL: 234-8035374004 E-mail: firstname.lastname@example.org