Studies on the infectivity of gametocytes of Plasmodium berghei (NK 65) in Anopheles stephensi.

The infectivity of gametocytes of Plasmodium berghei (NK 65) has been studied in laboratory bred Anopheles stephensi. Mosquitoes were fed daily on infected male and female Mastomys natalensis and subsequent development of the oocysts was monitored in the midguts. Maximum number of oocysts were found in mosquitoes which were fed on infected female mastomys on D8 and in male mastomys on D7 post-inoculation. During the next peak of gametocytaemia, very few oocysts developed. These findings suggest that gametocytes are maximally infective only during the first peak, later on their infectivity declines although having sufficient number of gametocytes in the circulation.