Epidemiological investigations on arbovirus infections at Igbo-Ora, Nigeria.

A study of arbovirus infections occurring in Igbo-Ora community was carried out between May and October 1975. Haemagglutination inhibition test performed on seventy-eight human sera showed a high prevalence of antibodies against all the six arboviruses used. Percentage of positive sera were as follows: Chikungunya, (28%); Yellow fever (36%); Dengue type 1 (67%); Dengue type 2 (45%). Prevalence of HI antibodies to West Nile and Wesselsbron viruses were 44% and 59% respectively. Virus isolation studies carried out on 148 blood samples yielded three viruses: Yellow fever, Dengue type 1 and Zika. Antibody conversions to these three viruses were demonstrated in seven persons within the period of study.