Environmental drivers of Ross River virus in southeastern Tasmania, Australia: towards strengthening public health interventions

Abstract

In Australia, Ross River virus (RRV) is predominantly identified and managed through passive health surveillance. Here, the proactive use of environmental datasets to improve community-scale public health interventions in southeastern Tasmania is explored. Known environmental drivers (temperature, rainfall, tide) of the RRV vector Aedes camptorhynchus are analysed against cumulative case records for five adjacent local government areas (LGAs) from 1993 to 2009. Allowing for a 0- to 3-month lag period, temperature was the most significant driver of RRV cases at 1-month lag, contributing to a 23·2% increase in cases above the long-term case average. The potential for RRV to become an emerging public health issue in Tasmania due to projected climate changes is discussed. Moreover, practical outputs from this research are proposed including the development of an early warning system for local councils to implement preventative measures, such as public outreach and mosquito spray programmes.

Epidemiologic Patterns of Ross River Virus Disease in Queensland, Australia, 2001–2011

“…Seasonal trends and variations between years suggest that climate may be the key determinant of larval and adult mosquito abundance, which subsequently affects RRV transmission. Rainfall is considered the most important climatic factor driving RRV prevalence because of mosquitoes relying on water to complete their life cycle 11,29,30. Gatton and others examined the spatio-temporal patterns of RRV distribution during 1991–2001 in Queensland,16 and found 85% of the notifications occurring in the summer and autumn and more than twice as many in the autumn as in the summer.…”

Developing Health-Related Indicators of Climate Change: Australian Stakeholder Perspectives

“…These events are predicted to increase with climate change [13,14,15]. A changing climate can also affect the transmission of climate-sensitive mosquito-borne diseases such as dengue fever and Ross River virus disease [16,17,18], in addition to food-borne diseases such as salmonellosis [19,20,21]. …”

Exploring the Potential for Ross River Virus Emergence in New Zealand

“…First, RRV persists in Tasmania (Robertson et al 2004, Werner et al 2012, which has a similar climate envelope to parts of New Zealand (Maguire 1994, Weinstein et al 1995. Second, the threat of RRV as an emerging disease has been demonstrated elsewhere in recent decades.…”

“…Given the need to allocate constrained biosecurity and health care resources to where they provide the greatest benefit in any country, formal predictive exercises need to be carried out for any potential future threat, such as RRV to New Zealand, to guide decisions regarding preventive management and incursion responses. For RRV in Australia, and indeed for vector-borne diseases in general (e.g., Hales et al 2002), such exercises generally involve correlational modeling of outbreak data against environmental variables (e.g., Werner et al 2012). However such an approach, at least for vector-borne agents such as RRV where vector and wildlife reservoir communities are highly variable, has proven nontransferable between regions (Kelly-Hope et al 2004, Jacups et al 2008, Tong et al 2008.…”

“…However, although the understanding of the mechanisms that are implicit in deterministic modeling makes it a potentially more valid approach than correlational work for investigating disease emergence, such a benefit comes at the cost of increased information requirements. For example, while correlational models of infectious diseases can be based on general environmental data (e.g., Hales et al 2002, Werner et al 2012), deterministic models require rate information for specific mechanisms (Tompkins et al 2002). Hence, our first aim was to use model construction and parameterization as an objective process for highlighting knowledge gaps regarding the assessment of RRV emergence potential in New Zealand.…”