Molecular xenomonitoring of Dengue, Chikungunya and Zika infections: a year-round study from two Dengue endemic districts of central India

Abstract

Background & objectives: Infections caused by arboviruses and transmitted by Aedes species mosquitoes are a serious health concern. India is endemic for diseases like Dengue, Chikungunya and recently Zika has been reported from few states. Vector control is the only way to contain these diseases, however, data regarding vectors from central India is lacking; to fulfill the lacuna we conducted this study. Methods: Entomological surveys were conducted from November 2017 to December 2018 for Aedes species in Dengue endemic areas of central India. The mosquitoes were identified, pooled and tested for the presence of Dengue, Chikungunya and Zika viruses by RT-PCR. The PCR products were sequenced to identify serotypes and genotypes of viruses. Results: A total of 2991 adults of Aedes specimens were collected and tested. Ae. aegypti (94.6%) was found to be the most abundant species. Highest mosquito density was recorded in the monsoon periods. Dengue (n=5) and Chikungunya (n=4) virus were detected from pools of female Ae. aegypti. One pool of male Ae. aegypti was positive for Dengue virus-3 and Chikungunya virus. Zika virus was not detected from any pool. Interpretation & conclusion: The findings suggest that Ae. aegypti is the principal vector of Dengue and Chikungunya, which is capable to transmit these viruses vertically. The findings have epidemiological importance and will be helpful to program managers.

Keywords

• aedes; chikungunya; dengue; vertical transmission; zika