Population genetic structure of Aedes (Stegomyia) aegypti (L.) at a micro-spatial scale in Thailand: implications for a dengue suppression strategy

PLoS Negl Trop Dis. 2013;7(1):e1913. doi: 10.1371/journal.pntd.0001913. Epub 2013 Jan 10.

Abstract

Background: The genetic population structure of Aedes (Stegomyia) aegypti (L.), the main vector of dengue virus, is being investigated in areas where a novel dengue suppression program is to be implemented. The aim of the program is to release and establish mosquito populations with impaired virus transmission capabilities. To model effects of the release and devise protocols for its implementation, information about the genetic structure of populations at a range of spatial scales is required.

Methodology/principal findings: This study investigates a potential release site in the Hua Sam Rong Subdistrict of Plaeng Yao District, Chachoengsao Province, in eastern Thailand which comprises a complex of five villages within a 10 km radius. Aedes aegypti resting indoors was sampled at four different times of year from houses within the five villages. Genetic markers were used to screen the mosquitoes: two Exon Primed Intron Crossing (EPIC) markers and five microsatellite markers. The raw allele size was determined using several statistical software packages to analyze the population structure of the mosquito. Estimates of effective population size for each village were low, but there was no evidence of genetic isolation by geographic distance.

Conclusions: The presence of temporary genetic structure is possibly caused by genetic drift due to large contributions of adults from a few breeding containers. This suggests that the introduction of mosquitoes into an area needs to proceed through multiple releases and targeting of sites where mosquitoes are emerging in large numbers.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aedes / classification
  • Aedes / genetics
  • Aedes / physiology*
  • Animals
  • Dengue / epidemiology
  • Dengue / prevention & control
  • Genetic Markers
  • Genetic Variation*
  • Humans
  • Insect Vectors*
  • Mosquito Control / methods
  • Thailand / epidemiology

Substances

  • Genetic Markers

Grants and funding

The study was funded by Bill and Melinda Gates Foundation through the Foundation for the National Institutes of Health (Grand Challenge in Global Health Program) and the Mahidol University Targeted Research Program Grant. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.