Dengue: Australia's other pandemic

Abstract

Pandemic dengue arrived in Australia in 2008-09. A large epidemic of Dengue Virus 3 (DENV-3) affected much of north Queensland, with over 900 cases and one death, in Cairns. This was accompanied by 18 imported viremic dengue cases into north Queensland from January to May 2009 and outbreaks of DENV-1, -2 and -4 in Townsville, Cairns and Innisfail, respectively. The virus was unique, with apparently shorter incubation periods, resulting in rapid transmission that exceeded the capacity of Queensland Health’s five-man dengue control team. Furthermore, potential pesticide resistance reduced the efficacy of some control measures. This unprecedented level of dengue activity has highlighted problems with the Dengue Fever Management Plan (DFMP), forcing the implementation of new interventions to control the epidemic. These included adoption of the Emergency Management Framework that allowed access to resources beyond those budgeted. New emergency teams conducted interior residual spraying and treating of containers in yards with methoprene and this was supplemented by SES volunteers, who delivered cans of surface spray to residents. This wide-ranging approach rapidly reduced transmission. Nonetheless, the presence of high populations of Ae. aegypti, that sustained epidemic transmission in much of north Queensland, highlights the need for the expansion of the DFMP to fund a comprehensive source reduction campaign. The incursion and establishment of the vectors Ae. aegypti and Ae. albopictus into eastern urban areas could dramatically increase the range of dengue transmission in Australia. Novel vector control measures, such as the use of life-shortening Wolbachia, offer the potential to eliminate dengue transmission in the future.