Not all mosquitoes carry diseases – most are just a nuisance. However, they can carry a range of diseases and during the warmer months, mosquito numbers are high along many parts of the Murray River and its surrounds.
Latest Health Alert
31/12/2024
A probable human case of Japanese encephalitis (JE) has been identified in a resident of northern Victoria, the first case of JE in Victoria this mosquito season. JE virus has also been detected through environmental surveillance in northern Victoria along the Murray River, and in mosquitoes and feral pigs in New South Wales this summer.
These findings indicate that JE virus is likely circulating in northern Victoria this summer.
JE virus can cause a rare but potentially serious infection of the brain and is spread to humans through bites from infected mosquitoes. Residents and people visiting northern Victoria, particularly inland riverine regions and near the Murray River, are potentially at higher risk of infection and should take measures to prevent mosquito bites. Avoid mosquito bites by using mosquito repellent containing picaridin or diethyltoluamide (DEET) on all exposed skin. Wear long, loose fitting clothing when outside, and ensure accommodation, including tents are properly fitted with mosquito nettings or screens.
In Victoria, JE vaccine is available free-of-charge for specific groups at higher risk of exposure to the virus, including eligible people in 24 high-risk LGAs in northern Victoria. Vaccination is available to protect you from JE, and it is free if you meet the eligibility criteria. Find out if you are eligible for a free JE vaccination and how to access it here
General advice
People should take action to prevent being bitten, particularly those who spend time near the region’s waterways.
We encourage people to:
- Use an effective mosquito repellent, containing either picaridin or DEET, on all exposed skin.
- Wear loose fitting clothes that cover your skin.
- Try to limit outdoor activity if lots of mosquitoes are about (usually dusk and dawn).
- Take action to prevent mosquito breeding around your home.
For more information, go to the Better Health Victoria's website by clicking here
For resources, click below:
Japanese encephalitis
- The risk of mosquito-borne infections will increase in the coming months (October to late April) in Victoria, as mosquito numbers do.
- This includes Japanese encephalitis, a rare but potentially serious infection of the brain caused by a virus that can be spread to humans through mosquito bites.
- Be prepared – Japanese encephalitis is a rare infection but one that can be very serious. Vaccination can protect you.
- Get the vaccine now to make sure you’re protected against Japanese encephalitis before mosquito season begins.
- Japanese encephalitis Virus (JEV) was first identified in Victoria in early 2022 and has again been detected in Victoria in December 2024.
- Although there is a vaccine for Japanese encephalitis virus, there are no vaccines against other mosquito-borne diseases. The best way to prevent diseases from mosquitoes is to avoid mozzie bites.
- Click the link below or contact your Local Public Health Unit to find out where you can be vaccinated.
JE Vaccination Eligibility
Vaccination against Japanese encephalitis (JE) is recommended for Victorians who meet the eligibility criteria. You are eligible for free JE vaccination if you:
- live in high-risk areas of Victoria and meet additional criteria.
- live or work at properties with pigs.
- work in mosquito surveillance or control.
- are going to high-risk areas for seasonal work.
For more information about JE vaccine eligibility criteria and how to access the vaccine, click here
See a list of local vaccine providers here. Any GP can order and administer the JE vaccine, so if your local GP is not on the existing list of providers, have a chat with them about ordering and receiving the vaccine.
Ross River virus
Ross River virus has been repeatedly detected in mosquitoes in these inland areas. Particularly in the summer months, there is increased risk that people living in or travelling to these areas may be infected by mosquitoes carrying Ross River virus.
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. 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.
For more information, click here
Murray Valley encephalitis
MVE virus was first isolated from patients who died from encephalitis in the Murray Valley in Victoria and South Australia in 1951. It was previously included as one of the causative agents in the disease called ‘Australian encephalitis’, which also included disease caused by Kunjin virus, another flavivirus. These viruses are now accepted as causing two separate diseases: MVE and West Nile/Kunjin. Since 2010, Kunjin has been known as West Nile/Kunjin virus.
MVE virus commonly infects humans without producing apparent disease (subclinical infection). Only one person in about 800 of those infected with MVE virus develops clinical disease. It may also cause a comparatively mild disease with features such as fever, headache, nausea and vomiting. In a small percentage of all people infected, mild disease may be a prodrome to disease progression and the involvement of the central nervous system. This can result in meningitis or encephalitis of variable severity. Signs of brain dysfunction, such as drowsiness, confusion, fitting, weakness or ataxia, indicate the onset of encephalitis.
For more information, click here
Seasonal workers
- If you are going to high-risk areas for seasonal work, you can have a free JE vaccination, regardless of Medicare status.
- Your best protection against mosquitoes and the diseases they can carry is to stop mosquito bites.
- Mozzies can bite through tight clothing. Cover up - wear long, loose-fitting clothing.
- Use mosquito repellents containing Picaridin or DEET on all exposed skin.
- Like sunscreen, mosquito repellent is only effective if applied to all exposed skin. Aim to apply a thin, even layer to all exposed skin on top of your sunscreen.
- It is important to reapply, especially after swimming or sweating as repellents are not water resistant.
For information on how to prevent mosquito-borne diseases after a flood or heavy rainfall, click here
Run a tourism business?
We have created a special fact sheet for those who have a hospitality business or provide guest accommodation. Click here to download.