PLoS Neglected Tropical Diseases (Oct 2024)

A change in circulating chikungunya virus variant impacts Aedes aegypti vector competence and spatiotemporal distribution of disease in Malaysia.

  • Izzati Kausar Azman,
  • Yoke Fun Chan,
  • Chong Long Chua,
  • Zainal Abidin Abd Mutalib,
  • Sarat Chandra Dass,
  • Balvinder Singh Gill,
  • Nor Hayati Ismail,
  • Jenarun Jelip,
  • Ming Keong Wan,
  • Wenn-Chyau Lee,
  • Indra Vythilingam,
  • Luke Alphey,
  • I-Ching Sam

DOI
https://doi.org/10.1371/journal.pntd.0012632
Journal volume & issue
Vol. 18, no. 10
p. e0012632

Abstract

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BackgroundIn 2008-2010, Malaysia experienced a nationwide chikungunya virus (CHIKV) outbreak caused by the Indian Ocean lineage E1-226V (valine) variant, adapted to Aedes albopictus. In 2017-2022, transition to an E1-226A (alanine) variant occurred. Ae. albopictus prevails in rural areas, where most cases occurred during the E1-226V outbreak, while Ae. aegypti dominates urban areas. The shift in circulating CHIKV variants from E1-226V to E1-226A (2009-2022) was hypothesized to result in a transition from rural to urban CHIKV distribution, driven by differences in Ae. aegypti vector competence for the two variants. This study aimed to: (1) map the spatiotemporal spread of CHIKV cases in Malaysia between 2009-2022; and (2) compare replication of E1-226A and E1-226V variants in the midguts and head/thoraxes of Ae. aegypti.Methodology/principal findingsSpatiotemporal analysis of national notified CHIKV case addresses was performed. Between 2009-2022, 12,446 CHIKV cases were reported, with peaks in 2009 and 2020, and a significant shift from predominantly rural cases in 2009-2011 (85.1% rural), to urban areas in 2017-2022 (86.1% urban; pConclusions/significanceThis study revealed that a change in circulating CHIKV variants can be associated with changes in vector competence and outbreak epidemiology. Continued genomic surveillance of arboviruses is important.