Bwamba virus infection: A sero-survey of veterbrates in five ecological zones in Nigeria

Abstract

Sera of humans, birds, domestic and wild animals from 28 localities in 5 ecological zones of Nigeria were tested for neutralizing antibody to Bwamba virus. A total of 984 human sera were tested, of which 516 (52·4%) were positive for Bwamba antibody. The highest prevalence (68·2%) was found in the southern guinea savannah zone. The prevalence in other zones were: 62·3% in derived savannah, 40·6% in swamp forest, and 32·1% in rain forest. The small number of samples tested from the Jos Plateau (northern guinea savannah zone) renders uninterpretable the high prevalence (74%) in this area. Significant differences in antibody prevalence were found between the relatively dry savannah areas (southern guinea and derived savannah) and the wet forested areas (swamp forest and rain forest). Except for a significantly lower prevalence of Bwamba antibody in urban dwellers in the wet forested zone as compared with rural dwellers, antibody prevalence was not significantly different for sites within each major ecologic zone. None of the 502 animal and bird sera tested was positive for Bwamba virus antibody. It is suggested that man is an important host in the transmission cycle of Bwamba virus and that Aedes (N.) circumluteolus is the major vector.