Estimates of Malaria Vectorial Capacity for Anopheles Culicifacies and Anopheles Stephensi in Rural Punjab Province, Pakistan1

Abstract

During the monsoon malaria-transmission season of 1978, infrequent feeding on humans coupled with reduced anopheline life expectancy contributed to low estimates of malaria vectorial capacity (number of infections distributed per case per day) for Anopheles culicifacies (−2 for Plasmodium vivax and −3 for P. falciparum) and An. stephensi (−4 for P. vivax and −5 for P. falciparum) at a previously malarious village in rural Punjab Province, Pakistan. Cattle and buffaloes interspersed throughout the village may have diverted host-seeking females from human hosts. The present range of vectorial capacity values may be representative for unstable malaria in rural Punjab during a nonepidemic year. Alterations in the degree of human feeding, longevity or population size would presumably have to occur before vectorial capacity would attain levels suitable for the occurrence of a malaria outbreak.