A three year longitudinal study on the seasonal Japanese encephalitis vector abundance in Thanjavur district, Tamil Nadu, India

Abstract

Japanese encephalitis is spread by paddy breeding infected vector mosquitoes of the Culex vishnui subgroup and Cx. gelidus and amplified by infection of pigs / Ardeidae birds in nature. A longitudinal study of seasonal vector abundance of JE vectors was monitored from 2011-2014 in 3 villages from Thanjavur district by monitoring the abundance resting in and around cattle sheds during dusk hours which showed Cx. tritaeniorhynchus (83.41% to 61.7%) and Cx. gelidus (9.83% to 33.19%) to be the predominant species. Study revealed the seasonal abundance of Cx. tritaeniorhynchus and the Cx. gelidus the predominant vectors present in Thanjavur district, Tamil Nadu. Vector abundance clearly demarcates the time of public health threat in this area. Residents in these areas should take personal protection to reduce the number of mosquito bites, which include minimizing vector exposure at dusk and dawn, covering the body, using insect repellents and sleeping under mosquito nets.