Some observations on Plasmodium falciparum gametocytaemia in natural infections in an endemic area of Koraput district, Orissa.

Peripheral P. falciparum gametocytaemia with respect to its minimum average time taken for appearance in peripheral blood, its peak density, duration of persistence in peripheral circulation, conversion rate and sex ratio was studied in 22 persons with natural infections in a village of Koraput district, Orissa. The minimum average time taken for the appearance of gametocytes was 9.3 days in children (below 15 years) and 8.9 days in adults (15 years and above). The peak count was low, the maximum density being 31/microliters. The duration of gametocytaemia in peripheral circulation was also short, the longest being 32 days. The gametocyte conversion rate on an average was 0.74% in children and 2.04% in adults. The mean sex ratio of micro:macro gametocytes was 1:2.6 in children and 1:6.2 in adults.