Invited Speaker Australian Society for Microbiology Annual Scientific Meeting 2018

Past, present and future strategies for control of arbovirus transmission by the Aedes aegypti mosquito (#83)

Andrew van den Hurk 1 , Brian Montgomery 2 , Scott Ritchie 3
  1. Public Health Virology, Forensic and Scientific Services, Department of Health, Queensland Government, Coopers Plains, Queensland, Australia
  2. Metro South Public Health Unit, Queensland Health, Coopers Plains, Queensland, Australia
  3. Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, Queensland, Australia

Dengue, Zika, chikungunya and yellow fever viruses are predominately transmitted to humans by the mosquito, Aedes aegypti. Historically, control of this species relies on application of insecticides to or removal of water-holding containers where larvae develop. Unfortunately, sustainable Ae. aegypti control has been difficult due to its close association with humans, (e.g. preference for human blood meals, indoor feeding and resting behaviour, and daytime biting habits). In the last two decades, novel developments in the vector control arsenal have provided the capacity to dramatically reduce virus transmission by Ae. aegypti. The first of these requires understanding of the biology of Ae. aegypti to maximize disruption of transmission cycles by targeted application of residual insecticides. The second development is strategies which involve mass release of modified mosquitoes. The most advanced of these is the release of Ae. aegypti transinfected with the Wolbachia bacterium. This strategy exploits two major phenotypes that Wolbachia infers on mosquitoes: reproductive manipulation to drive the bacteria into the target Ae. aegypti population and inhibition of virus replication and transmission. Finally, to prevent Ae. aegypti from invading areas outside of its current distribution, considerable resources are deployed for surveillance to ensure incursions are detected early and rapidly mitigated. A strategy combining arrays of mosquito egg traps (ovitraps) and molecular diagnostics has recently been developed and deployed operationally in southeast Queensland with the goal of confirming the continued absence of this species from the region. This is critical, because if Ae. aegypti were to establish in these heavily populated areas, then they would become receptive to arboviruses transmitted by this species. As roll out of these strategies gains momentum, ongoing monitoring of target Ae. aegypti populations will be essential, as will an epidemiological assessment of their impact on arbovirus transmission.