Acid phosphatase staining variations in <i>Onchocerca volvulus</i> microfilariae from Guinea Savanna of Nasarawa State, Nigeria

Abstract

Despite resounding control achievements in some areas of West Africa and the Americas, a recent estimate indicated that at least 37 million people remain infected mostly in Africa. The epidemiology of human onchocerciasis in various endemic areas of Africa and Latin America has been attributed to the existence of geographical strains of filarial parasitic Onchocerca (O.) volvulus. Studies were conducted in two endemic villages in Nasarawa State by staining of microfilariae for acid phosphatase activity after skin snipping with corneo-scleral punch. The result showed that forty eight (48%) percent of those sampled carried microfilariae. Two thousand, two hundred and fourteen (2, 214) microfilariae were stained. Four hundred and twenty nine (429) 19.4% followed the staining patterns described by previous workers as patterns V, VIII and XII. One thousand, seven hundred and eighty five (1,785=80.6%) had a different and new staining pattern. This suggested that O. volvolus in Akwanga Area of Nasarawa State is a different strain from those identified in Sudan savanna, Rainforest and the mountains of Jos Plateau. It was recommended that proper identification of species strains combined with proper study on vector and transmission patterns may lead to an integrated control strategy instead of relying on any one control method.

Keywords: acid phosphatase, staining variation, microfilariae, Onchocerca volvulus, Nasarawa State

Nigerian Journal of Parasitology, Vol. 32 [2] September 2011, pp.157-161