Deltamethrin impregnated bednets for the control of urban malaria in Kumba Town, South-West Province of Cameroon.

This study was conducted from January to December 1992 in Kumba, a town situated in the rain forest region of the South-West Province of Cameroon, and consisted of a longitudinal survey including parasitological and clinical studies. Forty households were chosen for the study and randomly divided into two groups, each with approximately 240 inhabitants aged < or = 15 years. One group received deltamethrin impregnated bednets and the other group had no nets (control). For the months of April, June and August (rainy season), deltamethrin impregnated bednets did not reduce malaria prevalence significantly, but the overall malaria prevalence for all months of the study was significantly reduced (chi 2 MH = 9.17, P = 0.002). Enlarged spleen rates (chi 2 MH = 6.73, P = 0.009) and spleen sizes (P = 0.0002) were also significantly reduced by the nets. However, the reduction in the geometric mean parasite density (GMPD) was not significant. Even though some of these reductions were statistically significant, they were relatively low in a global context compared with previous work done mainly in rural areas. In an urban environment, parents and children usually stay up late, and probably receive many mosquito bites before going to sleep.