Epidemiological investigations of Bancroftian filariasis in the coastal zone Liberia.

A survey in 5 study areas along the Liberian coast was conducted to gain information on the prevalence and importance of bancroftian filariasis. The examination of 2675 persons revealed prevalence rates between 2% and 37%. The median microfilarial densities (MfD50) ranged from 5 to 24 microfilariae in 20 mm3 capillary blood taken between 20.30 hours and midnight. Catalytic curves fitted to age-specific infection rates were used to estimate incidence (1% to 3%) and recovery rates. It was extrapolated from the survey results that in a population of 71,0000 there are 16,0000 to 20,0000 infected with Wuchereria bancrofti. An estimated 2500 to 40000 men suffering from hydroceles and 3700 to 40000 elephantiasis patients demonstrate that bancroftian filariasis has to be regarded a health problem in rural coastal Liberia.