Department of Health

Health warning on mosquitoes and Ross River virus in central Victoria

Health advisory

Status:
Active
Advisory number:
211117
Date issued:
23 Dec 2021
Issued by:
Adjunct Clinical Professor Brett Sutton, Chief Health Officer
Issued to:
Health professionals and the Victorian community residing in or travelling to central Victoria

Key messages

  • Residents and visitors in the central areas of Victoria are being warned to protect themselves against mosquito-borne diseases such as Ross River virus and Barmah Forest virus.
  • Ross River virus has been detected in mosquitoes in Moira Shire, Campaspe Shire and Greater Shepparton City Council. 
  • These viruses can cause symptoms including joint pain and stiffness, headache, fever, rash and fatigue.
  • The best protection from Ross River virus and other mosquito-borne diseases is to avoid mosquito bites. Protective measures include regularly using mosquito repellent containing picaridin or DEET on all exposed skin, wearing long, loose fitting clothing when outside, and ensuring accommodation, including tents, are properly fitted with mosquito nettings or screens.
  • Doctors 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.
  • A range of information relating to ways to protect against mosquito bites is available on the Beat the Bite campaign page on the Better Health Channel.

What is the issue?

Ross River virus has been detected in mosquitoes in Moira Shire, Campaspe Shire and Greater Shepparton City Council. There is increased risk that people living in or travelling to these areas may be infected by mosquitoes carrying Ross River virus.

Not all mosquitoes carry diseases – most are just a nuisance. However infected mosquitoes can carry a range of diseases including Ross River virus and Barmah Forest virus. While endemic across the state, these diseases occur more frequently in regional and coastal areas. 

Mosquito numbers are very high along parts of the Murray River from Gunbower to Yarrawonga.

Weather conditions predicted for  the upcoming week are favourable to mosquito biting and breeding.

As COVID-19 restrictions ease, there are greater opportunities to travel around Victoria and enjoy increased outdoor activity. Taking measures to avoid mosquito bites is therefore a critical step to protect against 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. 

Ross River virus is endemic throughout Victoria. All mosquitoes may carry a risk for Ross River virus infection, although the risk is greatest in rural and regional Victoria, including many coastal and riverine holiday areas. Infections occasionally also occur in outer metropolitan areas.

Symptoms and transmission

Ross River virus 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. 

Doctors 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.

Ross River virus infection must be notified by pathology services in writing within five days of diagnosis.

Prevention/treatment

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

  • Wear long, loose fitting clothes outdoors. 
  • Use effective mosquito repellents containing picaridin or DEET on all exposed skin.
  • Try to limit outdoor activity if lots of mosquitoes are about.
  • Use ‘knockdown’ fly sprays and plug-in repellent 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 areas where you gather to sit or eat.

Treatment is symptomatic, with rest advisable in the acute stages of the disease. There is no vaccine currently available commercially to protect against Ross River Virus disease.

More information

Clinical information 

Better Health Channel: Flu (influenza) – immunisation

Notifiable infectious diseases, conditions and micro-organisms

Consumer information

Better Health Channel: Beat the Bite

Contacts

For more information please contact the Communicable Disease Prevention and Control section at the Department of Health on 1300 651 160 (24 hours). 
 

Reviewed 24 December 2021

Health.vic

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