Mosquito Vector Competence for Japanese Encephalitis Virus.

Heidi Auerswald,Pierre-Olivier Maquart,Sebastien Boyer,Véronique Chevalier

doi:10.3390/v13061154

Abstract

Japanese encephalitis virus (JEV) is a zoonotic pathogen mainly found in East and Southeast Asia and transmitted by mosquitoes. The objective of this review is to summarize the knowledge on the diversity of JEV mosquito vector species. Therefore, we systematically analyzed reports of JEV found in field-caught mosquitoes as well as experimental vector competence studies. Based on the investigated publications, we classified 14 species as confirmed vectors for JEV due to their documented experimental vector competence and evidence of JEV found in wild mosquitoes. Additionally, we identified 11 mosquito species, belonging to five genera, with an experimentally confirmed vector competence for JEV but lacking evidence on their JEV transmission capacity from field-caught mosquitoes. Our study highlights the diversity of confirmed and potential JEV vector species. We also emphasize the variety in the study design of vector competence investigations. To account for the diversity of the vector species and regional circumstances, JEV vector competence should be studied in the local context, using local mosquitoes with local virus strains under local climate conditions to achieve reliable data. In addition, harmonization of the design of vector competence experiments would lead to better comparable data, informing vector and disease control measures.

Highlights

Japanese encephalitis (JE) is a vector borne zoonosis and one of the world’s leading encephalitic diseases, in the Asia-Pacific region [1]
We split the results into (i) confirmed vector species (Table 1, Figure 2) when their vector competence was proven by experimental infection and transmission, and Japanese encephalitis virus (JEV) was found in field-caught mosquitoes, (ii) potential vector species with proven experimental vector competence but no documented JEV in field mosquitoes
We classified 11 mosquito species as potential JEV vector based on experimental vector competence studies: Ae. detritus, Ae. dorsalis, Ae. japonicus, Ae. kochi, Ae. nigromaculis, Ae. notosciptus, An. tessellatus, Cx. tarsalis, Cs. annulata, Cs. inornata and Ve. funerea

Summary

Introduction

Japanese encephalitis (JE) is a vector borne zoonosis and one of the world’s leading encephalitic diseases, in the Asia-Pacific region [1]. The main epidemiological pattern is an enzootic cycle where the virus is transmitted between birds and/or pigs by mosquitoes [6]. Direct pig-to-pig transmission by oronasal infection was demonstrated under laboratory conditions [7]. The importance of this vector-free infection route for the maintenance of the JEV epidemiological cycle is substantiated by mathematical modelling using serological data from field investigations [8]. Mosquitoes are still considered the key players in terms of virus transmission and investigations of their capacity to efficiently pass on JEV are vital for risk assessments and public health recommendations. The main considered JEV vector species are Cx. tritaeniorhynchus, Cx. vishnui and Cx. gelidus [10,11,12]

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