Climate change impacts on Ross river virus in Australia

Abstract

Introduction Ross River virus disease is the most prevalent mosquito-borne disease in Australia, with 4400 cases annually. We explore how changing future climate, in combination with social responses, may alter the habitat and survival of vectors and hosts. Subsequent changes to the pattern and distribution of infections suggest a range of adaptation strategies for reducing transmission.

Methods We map projected changes to rainfall across Australia to 2100 under “dry” and “wet” scenarios and hypothesise how these changes may affect disease distribution over space and time.

Results Changes to transmission patterns will be regionally-specific. Increasing average temperatures will support virus activity in new regions, or for longer periods of each year, as long as humidity remains sufficient for vector survival. Outbreak patterns will change in some regions as increasing drought is punctuated by heavier rainfalls. Explosive outbreaks between periods of inactivity are increasingly likely in some areas. Epidemic regions bordering endemic regions may move towards endemicity. In coastal areas, saltwater vector breeding will be enhanced by increased tidal inundation with sea level rise. With population growth the number of people at risk of infection will increase each year.

Conclusion The pattern of infections in some local areas may change significantly from the historical norm as climate changes, while local adaptations, such as those to manage water deficit, may inadvertently increase vector habitat. Responses that are coordinated between state and local governments and across portfolios will be most successful and cost effective.