Department of Health

Health warning on mosquitoes and Ross River virus

Health advisory

Advisory number:
Date issued:
05 Dec 2018
Issued by:
Dr Brett Sutton, Acting Chief Health Officer, Victoria
Issued to:
Health professionals, aged care facilities, and the Victorian community.

Key messages

  • Residents and visitors to Victoria are being warned to protect themselves against mosquito-borne diseases such as Ross River virus and Barmah Forest virus as the summer season approaches.
  • These viruses can cause symptoms including joint pain and stiffness, headache, fever, rash and fatigue.
  • Mosquito-borne diseases occur more frequently in regional areas and Ross River virus has now been detected in mosquitoes in the Gippsland Lakes area around Ninety Mile Beach.
  • The best protection from these diseases is to avoid mosquito bites by regularly using mosquito repellent containing picaridin or DEET on all exposed skin, wearing loose fitting clothing when outside, and ensuring accommodation, including tents, are properly fitted with mosquito nettings or screens.
  • A range of information relating to protecting against mosquito bites is available on the Beat the Bite campaign page on the Better Health Channel.
  • Medical practitioners should consider the possibility of mosquito-borne disease in patients presenting with a compatible illness, especially after travel to rural or regional Victoria. 
  • A blood test early in the illness can indicate potential acute infection, and should be repeated two weeks later for confirmation.

What is the issue?

Not all mosquitoes carry diseases – most are just a nuisance; however, mosquitoes can carry a range of diseases including Ross River virus and Barmah Forest virus. These diseases can cause serious illness and occur regularly in regional Victoria. Ross River virus has now been detected in mosquitoes in the Gippsland Lakes area around Ninety Mile Beach.

The summer holiday season is a time of increased outdoor activity, so taking measures to avoid mosquito bites is a critical step to protect against such diseases.

Who is at risk?

Anyone is potentially at risk of being bitten by mosquitoes and while most bites will only cause minor swelling and irritation, an infected mosquito can transmit potentially serious diseases. All parts of Victoria where there are mosquitoes may carry a risk for Ross River virus infection, although the risk is greatest in rural and regional Victoria, including many coastal holiday areas. Infection appears to be rare in outer metropolitan areas.

Symptoms and transmission

Ross River virus and Barmah Forest virus disease are similar. Both can cause joint swelling and pain, fatigue and muscle aches which can persist for many months. A rash and fever may also develop. It takes three to nine days for symptoms of Ross River virus disease to occur after exposure, and occasionally up to 21 days. Barmah Forest virus disease symptoms occur between seven to ten days after a bite from an infected mosquito. While almost all people recover, symptoms may recur in some individuals for over a year or more. 


There are simple steps to protect against mosquito-borne diseases:

  • Wear long, loose fitting clothes if mosquitoes are around. 
  • Use effective mosquito repellents containing picaridin or DEET on all exposed skin.
  • Try to limit outdoor activity if lots of mosquitoes are about. The hours before and after sunrise and sunset is when most mosquitoes are more active but some will also bite in the middle of the day.
  • Use ‘knockdown’ sprays and plug-in vaporising devices indoors.
  • Sleep under mosquito nets treated with insecticides if you don’t have flywire screens on windows on your home, or are sleeping in an untreated tent.
  • Sleep under a mosquito net if camping out in the open.
  • Mosquito coils can be effective in small outdoor protected areas.

More information

Clinical information

Department of Heatlh and Human Services disease information and advice

Consumer information 

Beat the Bite campaign on the Better Health Channel

Order Beat the Bite resources online or email the infectious diseases team.


For more information please contact the Communicable Disease Prevention and Control section at the Department of Health and Human Services.

Authorised by the Victorian Government, 1 Treasury Place, Melbourne. 

Reviewed 06 December 2018


Contact details

Do not email patient notifications.

Communicable Disease Section Department of Health GPO Box 4057, Melbourne, VIC 3000

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