Dengue virus surveillance: circulation of DENV-1, DENV-2, DENV-3 and DENV-4 in mosquitoes around Taman Connaught, Cheras

Abstract

Dengue, a mosquito-borne viral infection that causes dengue fever, hemorrhagic fever and dengue shock syndrome, is on a drastic rise in recent years. In Malaysia, the distribution of dengue viruses is determined based on localized studies, where these data are essential to predict the epidemiology of dengue infections. Therefore, a study was conducted in Taman Connaught, Cheras, determining dengue virus serotypes in field caught Aedes mosquitoes. Out of 1,147 mosquitoes captured from September to December 2017, 156 Aedes spp. mosquitoes were identified based on their physical features using a digital microscope. Total RNA was then extracted from the head and thorax of the mosquitoes and subjected to reverse transcriptase-polymerase chain reaction (RT-PCR) with DENV-1, DENV-2, DENV-3 and DENV-4 primer sets, respectively. The results show that at least one DENV serotype was detected in 91% (n=142) out of 156 Aedes spp. mosquitoes. The predominant serotype detected was DENV-2 [47.44% (n=74)], followed by DENV-4 [8.97% (n=14)], DENV-3 [7.05% (n=11)] and DENV-1 [3.85% (n=6)], respectively. Co-circulation of DENV-2 and -4 was the predominant co-infection detected in Aedes spp. mosquitoes. We also present the first report of DENV-1, -2 and -4 co-infection in field-caught Aedes spp. Localized surveillance mechanisms based on serotype circulation in the mosquito vector can be an effective monitoring system for the government and public health sector in order to reduce the incidence of dengue hotspots.