Selective Feeding of Anopheles gambiae according to ABO Blood Group Status

Abstract

IN investigations of physiological factors affecting the selection of human hosts for feeding by the mosquito Anopheles gambiae (species A from Nkolmekok², Cameroons), pairs of subjects were chosen who contrasted in ABO blood group status. The experiments were conducted under conditions which simulated as closely as possible those under which females of A. gambiae normally bite. Because illumination was limited to a dim red light, counting how many of the twenty female insects used took a blood meal from the arm of a particular host proved difficult. We found, however, that even if only a very small blood meal was taken during the ten minutes' testing time, the ABO status of this meal could be reliably established within an hour, by extracting the blood from the mosquito's gut and performing direct agglutination tests on it with anti-A and anti-B sera. In over a hundred blind tests there were only two cases of possible error.