Ross River virus transmission in Darwin, Northern Territory, Australia

Abstract

The alpha virus Ross River virus (RR) is responsible for most of the confirmed cases of arbovirus disease in Australia and is responsible for periodic outbreaks of arbovirus disease in the NT (Whelan et al. 1994, Merianos et al. 1992, Tai et al. 1993). A mosquito monitoring program utilising CO2 baited traps has been in place in Darwin since 1979. There are currently 17 traps set weekly in various positions in the Darwin suburban area between sources of mosquitoes and urban areas. The usual pattern of adult abundance is high Ae. vigilax (Skuse) numbers from September to January and high Cx. annulirostris Skuse numbers from January to June. This paper outlines the annual incidence of RR disease in the 3 residential regions of Darwin and examines the vector and environmental variables in various suburban groupings of urban Darwin to determine if they could help explain the distribution of cases and hence assist in the prediction of risk periods for proactive mosquito control or disease awareness programs.