The status of human filariasis in north-western zone of Bauchi State, Nigeria.

In a nine-months epidemiological study to assess the status of human filariasis in north-western zone of Bauchi State, Nigeria, 3.5% prevalence was recorded in 8 communities. Of the 1536 persons examined, 54 were microfilaremic for three blood-dwelling filarial parasites. 22 (1.4%) were positive for Mansonella perstans, 10 (0.7%) and 22 (1.4%) had Loa loa and Wuchereria bancrofti respectively. W. bancrofti showed low microfilaremia in females of reproductive age with high degree of heterogeneity among communities. Most infected persons (81.5%) had counts less than 11 mf/20 mm3 of peripheral blood. Pruritus appeared much earlier in life while hydrocoele, limb and scrotal elephantiasis occurred much later in the population (> or = 40 years). Except in L. loa infections, mf-rate and mean mf-density increased with advancing host age (r = 0.713, P < 0.01). Fishermen, nomads and farmers had significantly higher infection rates (P < 0.05) than other occupational categories. Suggestions on the disease intervention involving treatment, prevention and vector control are highlighted.