Seasonal dynamics and relative abundance of seven Japanese encephalitis vectors of Culex sitiens group and their association with meteorological factors in various ecological habitats of Chandigarh and its surrounding areas

Abstract

Japanese encephalitis (JE) is one of the most common cause of acute viral encephalitis which poses serious infection of the brain. Species under Culex sitiens group are major vectors responsible for the transmission of JE. The knowledge about the occurrence of Culex sitiens group in Chandigarh and its adjoining areas is very scanty. Hence, present investigations have been carried out to study seasonal dynamics and relative abundance of JE vectors in these areas. Detailed surveys have been carried out in various ecological habitats of Chandigarh from June 2017–November 2019. The monthly meteorological parameters of the study–area like temperature, rainfall, and relative humidity were compared and statistically correlated with JE vector density. As many as 34 mosquito species belonging to 8 genera have been recorded. Genus Culex contributed maximum (69.40%) of the total catch which included 7 incriminated JE species from the studied habitats. These vectors showed highest density in monsoon and post–monsoon periods. The abundance of Culex sitiens vectors indicates their importance for evaluation of the seasonal dynamics which ultimately demarcates the risk of JE outbreak. The observation over a period of three years is highly significant to assess the seasonal dynamicity of JE vector population in different seasons and its abundance in different ecological habitats.