A laboratory-based study to explore the use of honey-impregnated cards to detect chikungunya virus in mosquito saliva.

Lisa Fourniol,Yoann Madec,Marie Vazeille,Laurence Mousson,Anna-Bella Failloux,Luciano Andrade Moreira

doi:10.1371/journal.pone.0249471

Abstract

Mosquito control is implemented when arboviruses are detected in patients or in field-collected mosquitoes. However, mass screening of mosquitoes is usually laborious and expensive, requiring specialized expertise and equipment. Detection of virus in mosquito saliva using honey-impregnated filter papers seems to be a promising method as it is non-destructive and allows monitoring the viral excretion dynamics over time from the same mosquito. Here we test the use of filter papers to detect chikungunya virus in mosquito saliva in laboratory conditions, before proposing this method in large-scale mosquito surveillance programs. We found that 0.9 cm2 cards impregnated with a 50% honey solution could replace the forced salivation technique as they offered a viral RNA detection until 7 days after oral infection of Aedes aegypti and Aedes albopictus mosquitoes with CHIKV.

Highlights

Female mosquitoes are hematophagous arthropods that need blood for egg production and plant nectar as energy source for flying [1]
One viral Chikungunya virus (CHIKV) RNA can be detected 7 days after depositing one viral particle on filter papers impregnated with a 50% honey solution (Fig 1c)
Our study shows that filter papers could replace the forced salivation technique to detect viral RNA in saliva of Ae. aegypti and Ae. albopictus

Summary

Introduction

Female mosquitoes are hematophagous arthropods that need blood for egg production and plant nectar as energy source for flying [1]. While blood is a key element for pathogen transmission, sugar source is pivotal for the survival of male mosquitoes and female fecundity [2]. Mosquitoes store sugar meals in large ventral diverticulum, the crop and sugar is poured out from time to time into the midgut for digestion and absorption [3]. When getting blood on a viremic host, a competent female mosquito ingests viral particles which penetrate inside midgut epithelial cells and replicate. When the female mosquito has a subsequent blood meal, the virus is inoculated in the vertebrate host with the saliva delivered [4]. When feeding on a sugar source, saliva is excreted and if infectious, virus is expelled

Methods

Results

Conclusion