Prevalence of Wuchereria bancrofti in Georgetown, Guyana.

A random sample bloodsmear survey was conducted during evening hours in Georgetown, Guyana, to determine the prevalence of Wuchereria bancrofti microfilariae. In all, 182 of 2,818 persons tested (6.5%) yielded positive results--indicating that the overall prevalence of Bancroftian filariasis has not diminished and may be on the rise. Relatively high prevalences found in children and adolescents point to active transmission. It appears likely that certain socioeconomic and environmental factors have been contributing to such transmission, and that similar factors could encourage increased transmission elsewhere in the Americas as well.