Relationship between Salinity and Breeding of Anopheles gambiae in North-Eastern Tanganyika

Abstract

A FEATURE of interest in the transmission of malaria in the Pare area of Tanganyika, before residual spraying, was the low sporozoite rate in A. gambiae, infections of less than 1 per cent normally occurring. Two factors thought to contribute to the low sporozoite-rate were facultative feeding on cattle, and a low survival-rate in the vector^1,2. A further possibility, that could not be excluded, was that the local strain of A. gambiae was also relatively resistant to infection or exhibited some innate difference in behaviour that reduced its chance of acquiring an infection, compared with strains in other areas. The existence of a low sporozoite-rate in salt-water A. gambiae on the humid coast of Tanganyika³ gave rise to speculation as to whether the presence of saline soils in the Pare area was not associated there also with the low sporozoite-rate.