Australians are being urged to protect themselves against mosquito bites this summer, with new research finding warmer temperatures significantly increase the risk of Ross River virus across much of the country.
A scoping review led by the University of Adelaide and published in the Australian and New Zealand Journal of Public Health analysed 30 studies examining the relationship between temperature and Ross River virus, as well as Barmah Forest virus.
The researchers found rising temperatures were linked to increased infection risk, particularly in coastal and riverland regions.
Around 3,000 cases of Ross River virus are reported in Australia each year. The mosquito-borne disease can cause rash, fever and joint pain, and while most people recover in a few weeks, some experience longer-lasting symptoms that can affect quality of life.
“Studies found that maximum temperatures are linked to higher Ross River Virus cases in coastal Australia, particularly in Queensland (Brisbane, Cairns, Townsville, Mackay, Gladstone, Bundaberg, Redland and Darling Downs), New South Wales (North-East NSW), Tasmania (Sorell region), and WA (Mandurah),” said lead author Christina Mary Varghese from the School of Public Health at the University of Adelaide.
However, the relationship between temperature and infection risk varied by location.
“Some studies found that minimum temperature appeared to increase the risk of the Ross River Virus infections in Darwin and in some inland regions of SA, Victoria and Queensland,” Varghese added.
Researchers noted that predicting outbreaks remains difficult due to the complex mix of factors involved, including rainfall, humidity and stagnant water.
“It is very hard to predict Ross River Virus outbreaks, with a complex range of factors contributing to increased risk, including rainfall, humidity, and stagnant water conditions,” Varghese said.
“But we know that cases are more likely when temperatures are between 17 and 31 degrees, with infections spiking when temperatures are around 26 degrees. That’s why it’s important for Australians to protect themselves from mozzie bites over the Christmas and New Year period.”
The review also examined Barmah Forest Virus, finding infection risk was linked to minimum temperatures in both coastal and inland areas.
“One of our biggest findings was that studies of Ross River Virus and Barmah Forest Virus have mostly centred on the coast. There is very little data on smaller towns and few related to Ross River Virus in Queensland.”
With more people travelling, camping and spending time outdoors during summer, the overarching advice from researchers is to wear light-coloured clothing, use mosquito nets and apply repellent to exposed skin.
Senior author Professor Peng Bi from the University of Adelaide said the review also highlighted major gaps in understanding how climate change may affect future disease patterns.
“There has been no Australian based study assessing associated healthcare costs, nor projecting future disease burden under different climate change scenarios – this is a key knowledge gap that needs to be addressed,” Bi said.
“We need to better understand how our changing climate is going to influence risk in different regions. We also need to fill the big gaps in research across inland Australia – so we can track how things change over time.”
Public Health Association of Australia chief executive Terry Slevin said the findings were particularly relevant ahead of the launch of Australia’s Centre for Disease Control in January.
“As the Australian weather warms due to climate change, we are likely to see different parts of Australia exposed to mosquito carried diseases like Ross River Fever and Barnah River Virus. Australia’s Centre for Disease Control will be monitoring these issues and is already providing advice on mosquito bite prevention.”
IMPORTANT LEGAL INFO This article is of a general nature and FYI only, because it doesn’t take into account your personal health requirements or existing medical conditions. That means it’s not personalised health advice and shouldn’t be relied upon as if it is. Before making a health-related decision, you should work out if the info is appropriate for your situation and get professional medical advice.