Prevalence of L. loa and M. perstans filariasis in southern Cameroon.

The prevalence and microfilarial density of Loa loa and Mansonella perstans filariasis have been determined in three successive surveys in one village in the dense rainforest of Southern Cameroon. The prevalence of L. loa microfilaraemia was 30.9% with a geometric mean density of 81.4 microfilariae/30 microliter blood. There was no difference between men and women. The prevalence increased with age from 14.5% at 0-9 years to 52.9% at 40-49 years, whereafter it stablized. The microfilarial density increased until the age of 30-39 years. The highest densities have been found around noon, although the difference was not significant. The prevalence of M. perstans microfilaraemia was 26.6% with a median density of 2.0 microfilariae/30 microliter blood. Both prevalence and density were increasing with age and were higher for men than for women. The time of day that the blood sample was taken had no influence on the microfilarial density of M. perstans.