Malaria Outbreaks in Villages in North Karnataka, India, and Role of Sibling Species of <i>Anopheles culicifacies</i> Complex

Abstract

Investigations on malaria outbreaks and role of sibling species complex of principal rural malaria vector Anopheles culicifacies were carried out in villages in north Karnataka, India from 1997 through 2014. Information regarding densities, resting and breeding habitats of malaria vectors prevalent in the area was also generated so as to formulate an appropriate vector control strategy. The Slide Positivity Rate (SPR), Slide Falciparum Rate (SFR) and Pf proportion was 43.1%, 35.9% and 83.3%, respectively. Three sibling species A, B, and C of An. culicifacies were found sympatric with cumulative percent composition of 63.7, 28.2 and 8.1, respectively. Per man hour and per structure densities of An. culicifacies , An. culicifacies and An. culicifacies varied from 0 to 27.5 and 0 to 56.0, 0 to 0.5 and 0 to 7.0 and, 0 to 2.5 and 0 to 7.5, respectively. The proportion of semi-gravid and gravid females was more as compared to fully fed and unfed females which indicated that most of the females rested indoor. Streams/river, wells, seepages and irrigation tanks are the major habitats supporting breeding of An. culicifacies . Integrated vector managements by indoor residual spraying of effective insecticide as per national guidelines along with biological control methods especially use of larvivorous fish Gambusia affinis and Poecilia reticulate are suggested to control malaria in the area.