[Monthly variations in the level of infestation and the potential for transmission of Biomphalaria pfeifferi in 2 aquatic systems in Lwiro, Democratic Republic of Congo].

This study of variations in the rate of infestation by Biomphalaria pfeifferi and risk of schistosomiasis transmission was carried out to determine optimal timing for control measures. The study was conducted in two aquatic ecosystems, i.e. creek and fish pond, in the Lwiro region located in the eastern part (sud-Kivu) of the Democratic Republic of Congo. Biomphalaria pfeifferi infestation rates were high in the creek from November to January and consistently low in the fish pond. The risk of schistosomiasis transmission to man was highest in the creek especially during the months of January, February, May, and September. The risk of transmission was always less than 16% in the fish pond. Based on these findings, the optimal timing for control measures is the dry season for creeks and the rainy season for fish ponds.