Mansonella perstans microfilaraemia among the Bori community in the Niger Delta area of Nigeria.

Night and day blood surveys for filariasis were conducted among inhabitants of Bori Local Government Area in the Niger Delta area of Nigeria between October 1983 and July 1984. Of the 1674 persons examined 47.0% had microfilaraemia. The infections were due to Mansonella perstans only. The prevalence of the infection was higher among males (51.8%) than among females (42.4%), and increased with age in both sexes. Eight persons were found with elephantoid scrotums and all had microfilariae of M. perstans.