The epidemiology of O'nyong—nyong in the Kano Plain, Kenya

Abstract

Age-specific prevalence rates of antibody to O'nyong-nyong virus were determined in samples of the population in the Kano Plain, near Kisumu, and Bunyala. Presented graphically, the rates show a clear picture indicating transmission leading to an average incidence of 10–20% per annum, commencing 10–15 years before the surveys (which were carried out in 1973). Incidence in the few years prior to the surveys is examined in more detail, together with results from other surveys of young children in the Kano Plain. There was apparently a decline in incidence during these years, and additional evidence from investigations of febrile cases and from mosquito studies strongly suggests that transmission had died away by the end of the period.