The Plasmodium falciparum infection status of two major anopheline vectors in three hyper-, meso-, and hypoendemic districts in Odisha, India

Abstract

Abstract In-depth understanding of malaria transmission dynamics in a region can be assessed by identifying the vector populations of infected mosquitoes, Anopheles spp. (Diptera: Culicidae), and by quantifying the infectiousness extent. In this study of malaria transmission dynamics relating to vector incrimination in three districts of Odisha, India – hyperendemic Kalahandi, mesoendemic Bargarh, and hypoendemic Cuttack – we examined how quality and quantity of plasmodial infection rates vary among mosquito species and their organs and among districts. The minimum infection rate of Plasmodium falciparum sporozoite for Anopheles culicifacies was highest in Kalahandi and nil in Cuttack. However, for A. annularis, the rate was highest in Cuttack, followed by Kalahandi and Bargarh. In Kalahandi, the gland-positive rate was higher for A. culicifacies, but in Cuttack, it was higher for A. annularis. To quantify plasmodium infection in salivary glands and guts of anopheline vectors, quantitative polymerase chain reaction was performed. We observed higher parasite density in glands than in guts of vector mosquitoes in the three districts. The findings demonstrate that plasmodium-infected vectors preferentially bind sporozoites to salivary glands in the three study areas. The results improve understanding of infection status within malaria vectors and how parasite population density may affect transmissibility, which will, in turn, provide baseline evidence to develop intervention measures.