Circulation of Arboviruses in Aedes mosquitoes in some Northern provinces, Vietnam, 2016-2019

Abstract

Amongst Aedes-borne Arboviruses, together with DENV, infection of ZIKAV and CHIKV has been spread to many countries and regions in the world. Aiming to investigate the circulation of DENV, CHIKV and ZIKAV amongst Aedes populations, the cross-sectional study was conducted in Nam Dinh and Hanoi between 2016-2019. In 2006, the study was implemented in 3 communes/quarters in Nam Dinh and 6 in Hanoi. The results demonstrated that Ae. aegypti Ae. albopictus mosquitoes were present in the majority of study sites, with a particularly higher percentage in urban sites where clusters of dengue infections have been detected and reported annually. A total of 622 Ae. aegypti and Ae. albopictus individuals from 9 sites were analyzed by multiplex RT-PCR assay detecting DENV/CHIKV/ZIKAV, but no infected mosquitoes were found. Additional analysis of a total of 478 Ae. aegypti individuals collected at 3 surveillance sites of Hanoi in 2019 did not detect infected mosquitoes either. In conclusion, there is still the prevalence of Aedes mosquitoes in Nam Dinh and Hanoi, whereas DENV,
CHIKV or ZIKAV infected mosquitoes remain not detected yet. Surveillance of Arbovirus circulation in mosquitoes needs to be maintained and additional molecular assays such as Pan RTPCR allowing to screening virus genuses will help increase surveillance performance.