In the wake of Tropical Cyclone Alfred, mosquito scientists at QIMR Berghofer say there is an increased risk of arboviruses (mosquito-borne diseases) across South East Queensland and Northern New South Wales, and are urging affected communities to take action to prevent the spread of potentially deadly disease.
The recent extreme weather event has created ideal conditions for mosquito breeding, raising concerns about potential outbreaks of Japanese encephalitis and Ross River virus.
Dr Brian Johnson from QIMR Berghofer’s Mosquito Control Laboratory says that warm seasonal temperatures, combined with large areas of standing water created by the heavy rains and coastal flooding from Cyclone Alfred, provide an ideal environment for the spread of disease.
“Residents should expect a significant increase in mosquito numbers beginning in 1 to 2 weeks after the cessation of rain and the settling of flood waters. Elevated mosquito populations are likely to persist for several weeks until floodwaters recede.”
“Of particular concern is the potential introduction of Japanese encephalitis virus (JEV) to coastal Queensland. While JEV has been circulating in the Darling Downs and Murrumbidgee region, the large flooding resulting from Cyclone Alfred may increase the risk of its spread to new areas,” Dr Johnson said.
To protect yourself from mosquito bites, especially during dawn and dusk when mosquitoes are most active:
- Wear long sleeves and long trousers when outdoors, particularly at dawn and dusk when mosquitoes are most active.
- Apply mosquito repellent to any exposed skin.
- Use traditional repellents containing DEET or Picaridin for best results.
- Consider natural repellents with lemon eucalyptus oil, but reapply every couple of hours.
- Empty water reservoirs around the home including pot plant saucers, clogged rain gutters and pet bowls.
More broadly, scientists believe the expected mosquito population boom is linked to changes in climate, extreme weather events, and land use – which has a direct impact on the spread of mosquito-borne diseases.
While there is a vaccine available for JEV, there are no treatments for arboviruses readily available for humans.
Researchers at QIMR Berghofer are currently working to uncover new treatments for Japanese encephalitis.
Dr Daniel Rawle from QIMR Berghofer’s Emerging Viral Diseases laboratory says that while only one in 250 people infected with Japanese encephalitis develops symptoms, the disease can be severe for those who do. Among symptomatic cases, one-third will die from the illness, while another third will become seriously ill, requiring long-term hospital care and potentially experiencing prolonged or permanent disability.
“We are trying to understand why Japanese encephalitis causes mild symptoms in some people but leads to severe illness or even death in others. Our research focuses on how this virus infects neurons and affects the brain in different ways, helping us find better ways to treat and prevent the disease.”.
“It is important the community understands that mosquito disease threats are likely to increase in coming months and years. There’s an urgent need to unpack the biological mechanisms of arboviruses, so we can supercharge the development of treatments for Australians as well as globally.”
Dr Rawle’s and Dr Johnson’s teams have recently been awarded a National Health and Medical Research Council Grant to study the impacts of climate change on vector borne diseases. The researchers are also incredibly grateful for support from the Brazil Family Foundation's special purpose donation: 'Responding to the unprecedented Japanese Encephalitis virus outbreak in Australia'.
For more information on arboviruses, head here: https://www.qimrb.edu.au/researchers-and-labs/emerging-viral-diseases