Acta Tropica, 48(1991)137-147 137 Elsevier ACTROP 00108 The occurrence of loiasis, mansonellosis and wuchereriasis in the Jarawa River Valley, Central Nigeria G.O. Ufomadu 1, B.E.B. Nwoke 2, J.I. Akoh a, Y. Sato 3, G.O.C. Ekejindu 1, A. Uchida 3, K. Shiwaku 4, M. Tumbau 1, and K.K. Ugomo ~ a Entomology and Parasitology Division, Nigerian Institute for Trypanosomiasis Research, Vom, Nigeria, 2Department of Zoology, University of.los, Jos, Nigeria, 3Department of Environmental Biology, Asabu University, Japan, and 4Department of Parasitic Disease, Aichi Medical University, Aichi 480-11, Japan (Received 16 May 1989; accepted 29 March 1990) In a study to assess the status of filariasis in the Jarawa River Valley of the savanna area of Nigeria, 940 self-selected residents from 10 villages were examined between March 1984 and April 1987. Overall results showed 105 (11.2%) had microfilaraemia and/or clinical signs of filariasis. Sixty-four (6.8%) and 20 (2.1%) persons, respectively, were infected with Mansonella perstans and Loa loa microfilariae (raft). Four of the 28 villagers examined had Wuehereria bancrofti mff in their night blood samples whereas 17 (1.8%) of all residents surveyed had clinical filariasis mainly due to lympho-obstructive manifestations: hydrocele (n = 11, 64.7%); enlargement of the inguinal nodes (n = 8, 47.1%) and elephantiasis (n = 2, 11.8%). Key words: Loa loa; Mansonella perstans; Wuchereria bancrofti; Microfilaraemia; Savanna; Nigeria Introduction Human filariasis has a wide geographical distribution especially in the humid tropical zone of Africa, South America, the Caribbean islands, South-east Asia and the Pacific islands where it constitutes a major public health problem (WHO, 1984). In West Africa, mansonellosis, loiasis and wuchereriasis have been reported (Gordon et al., 1950; Bell, 1967; Buck et al., 1978; Kuhlow and Zielke, 1978; Sofoluwe et al., 1978). These filarial infections have been recorded mainly in the coastal and rain-forest zones of Nigeria (Wyatt, 1967; Ogunba, 1977; Hori et al., 1984; Udonsi, 1986, 1988). Reports on the distribution of filariasis in the savanna region of Nigeria are rather scanty (Courtney 1923 quoted by Sasa, 1976; Wijeyaratne et al., 1982; Shiwaku et al., 1986) inspire of existing ecological conditions which favour the breeding of vectors of filariasis and filarial transmission. The present national endeavour is to provide baseline data for a coherent and integrated control of filariasis and its vectors Correspondence address." G.O. Ufomadu, Entomology and Parasitology Division, Nigerian Institute for Trypanosomiasis Research, P.M.B. 03, Vom, Plateau State, Nigeria. 0001-706X/90/$03.50 © 1990 Elsevier Science Publishers B.V. (Biomedical Division)