Entomo-virological surveillance of arboviruses in the Americas: prospects for the use of paper-based nucleic acid stabilization materials.

Abstract

Arthropod-borne viruses (arboviruses) represent a major public health burden for people living or visiting tropical and subtropical countries, where an endemic/epidemic cycle has been successfully established for Orthoflavivirus denguei, Alphavirus chikungunya, and O. zikaense. The risk for the reemergence of other viruses in the urban cycle in the Americas, such as A. mayaro and O. flavi is also of major concern, which justifies the intensification of active surveillance in urban, rural, and sylvatic areas to determine the virus activity in different settings. Entomological surveillance consists mainly of collecting, identifying, and estimating the relative densities of the main disease-transmitting vector species, and more recently, estimating infection rates for the more relevant pathogens. The new approaches for monitoring arthropod vectors of medical importance pose new challenges, including maintaining the cold chain to preserve the pathogen infectivity or nucleic acid stability, especially for RNA genomes, such as those of the main arboviruses. Hence, alternatives such as mosquito traps equipped with solid-phase materials impregnated with honey baits for mosquito feeding, saliva expectoration, and nucleic acid stabilization have been gaining popularity as they can be used as an early warning system to provide arbovirus genetic information useful in molecular epidemiology studies. Here, we present the state of the art in the use of this approach and highlight the need for exploration of the potential of different available solid-phase materials for nucleic acid immobilization and stabilization during mosquito feeding on honey-baited traps. The current challenges for the successful implementation of feasible entomo-virological surveillance as a routine arbovirus surveillance tool in mosquitoes in urban and rural settings of endemic areas are also discussed.