Comparative Analysis of the Diagnostic Methods Used in Detecting River Blindness in Selected Endemic Areas of Imo State, Nigeria

Abstract

Onchocerciasis also known as river blindness is a chronic parasitic disease caused by the filarial worm Onchocerca volvulus. This study was a cross sectional experimental study carried out to compare the diagnostic methods used in detecting river blindness in selected endemic areas of Imo state, Nigeria. The multistage sampling technique was adopted to select samples for the study. All subjects used for this study gave an informed consent to be part of the study. Bloodless skin snips were collected from the center of the nodule or other parts of the body with the assistance of a laboratory scientist and taken to the laboratory for analysis. A total of four hundred inhabitants of the studied communities (Umulolo, Amuro, Umuna, Umunumo, Onicha, Nzerem, Umuneke and Umulewe) were examined. Out of these, the number infected by onchocerca volvulus based on Skin-Snip Microscopy, Polymerase Chain Reaction (PCR), Mazzotti test, Dietylcarbamazine (DEC) patch test and Enzyme linked Immunosorbent Assay (ELISA) test were 59, 197, 50, 107, 201 respectively. SPSS analysis using the one way ANOVA showed a significance difference (P< 0.05) in the sensitivity of the PCR, Skin Snip Microscopy, Mazzotti, DEC Patch test and ELISA used for detecting Onchocerca volvulus in all the study areas. In conclusion, the diagnostic screening efficiency of ELISA and PCR were observed to be higher than that of the other diagnostic methods analyzed. It was recommended that further evidence-based, comparative research studies on current and conventional diagnostic methods should be done to ascertain reliability, reproducibility, sensitivity and accuracy of methods used for detecting River Blindness. Keywords: River Blindness, Onchocerciasis, Skin-Snip Microscopy, Polymerase Chain Reaction (PCR), ELISA test.