MALARIA AND RICE GROWING IN THE SENEGAL R IVER DELTA (SENEGAL)

An epidemiological survey of malaria was carried out from September 19 92 to November 1994 in three villages located in the Senegal river del ta, two villages growing rice in irrigated fields and one practicing t raditional rain water agriculture. Entomological observations showed t hat Anopheles pharoensis is the main anopheline species caught in the area with a high population density in the rice growing villages. The population density of species of the An. gambiae complex, represented by An. gambiae s.s., An. arabiensis and An. melas is low. Agressivity rates and anthropophlic indexes of An. pharoensis females are high but their parity rates are low. The malaria transmission is weak and was not perceptible in the area as shown by the negative results obtained with the ELISA tests and the examination of salivary glands. Parasitol ogical indexes, malaria morbidity and incidence rates are low and are in agreement with the entomological data. In the Senegal river delta, irrigation has, on the whole, increased the An. pharoensis density but both malaria transmission and incidence rates did not rise.