Studies on filariasis in Bauchi State, Nigeria. II. The prevalence of human filariasis in Darazo Local Government area.

In an eleven months study of eleven communities of Darazo Local Government Area of Bauchi state, northern Nigeria, 293 (21.7) of 1,349 persons examined harboured various filarial parasites. Of the sampled population, 18%, 1.9%, 1.6%, 0.5% and 0.2% had microfilariae of Onchocerca volvulus, Wuchereria bancrofti, Mansonella perstans, M. streptocerca and Loa loa respectively. Of the 637 females examined, 90 (14.1%) were infected, while 203 (23.5%) of 712 males sampled had filarial infections. The high rate in males was significant (P < 0.001). O. volvulus mf-rate increased gradually from the first decade to the seventh decade of life but declined thereafter. Prevalence of bancroftian filariasis was consistently lower in females of reproductive age, while the distribution of various filarial parasites varied significantly among age groups and communities (P < 0.05). Fishermen (42.9%), farmers (42.4%) and cattle rearers (40.9%) were the most affected occupational categories. Control strategies are highlighted.