Studies on Bancroftian filariasis in Liberia, West Africa. I. Distribution and prevalence in the north-western savanna area.

A nightblood survey was carried out in 17 villages in the savanna area in Upper Lofa in Liberia. A total of 1968 people was examined for the prevalence of microfilariae of Wuchereia bancrofti and for clinical symptoms of filariasis. 279 (14,2%) persons proved to be microfilaria carriers. Men were almost twice (19,0%) as much infected than women (10,4%). Only two cases of leg elephantiasis and one breast elephantiasis were found. Enlargements of scrotum were seen in 60 men (6,9%). The scrotal enlargement rate increased steadily with age.