Circulation of West Nile virus in mosquitoes approximate to the migratory bird stopover in West Coast Malaysia

PLoS Negl Trop Dis. 2023 Apr 6;17(4):e0011255. doi: 10.1371/journal.pntd.0011255. eCollection 2023 Apr.

Abstract

Being a tropical country with a conducive environment for mosquitoes, mosquito-borne illnesses such as dengue, chikungunya, lymphatic filariasis, malaria, and Japanese encephalitis are prevalent in Malaysia. Recent studies reported asymptomatic infection of West Nile virus (WNV) in animals and humans, but none of the studies included mosquitoes, except for one report made half a century ago. Considering the scarcity of information, our study sampled mosquitoes near migratory bird stopover wetland areas of West Coast Malaysia located in the Kuala Gula Bird Sanctuary and Kapar Energy Venture, during the southward migration period in October 2017 and September 2018. Our previous publication reported that migratory birds were positive for WNV antibody and RNA. Using a nested RT-PCR analysis, WNV RNA was detected in 35 (12.8%) out of 285 mosquito pools consisting of 2,635 mosquitoes, most of which were Culex spp. (species). Sanger sequencing and phylogenetic analysis revealed that the sequences grouped within lineage 2 and shared 90.12%-97.01% similarity with sequences found locally as well as those from Africa, Germany, Romania, Italy, and Israel. Evidence of WNV in the mosquitoes substantiates the need for continued surveillance of WNV in Malaysia.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Birds
  • Culex*
  • Culicidae*
  • Humans
  • Malaysia / epidemiology
  • Mosquito Vectors
  • Phylogeny
  • RNA
  • West Nile Fever*
  • West Nile virus* / genetics

Substances

  • RNA

Grants and funding

This work is supported by the Ministry of Higher Education Grant, Malaysia – France Bilateral Research Collaboration 2021 (MATCH 2021) with the grant number KPT MATCH/2021/5540495 (ARY) under Project In Vitro Differential Neuropathogenicity of Nonstructural Proteins (NSPs) of West Nile Virus isolated from Southeast Asia and Europe; and Universiti Putra Malaysia Grantmanship - Geran Putra Berimpak (UPM.RMC.800/2/2/4-GPB-9702300) (ARY). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.