TranslateMosquito-borne diseases
Some mosquitoes carry viruses that can make humans sick. These viruses are spread to humans by the bite of an infected mosquito. Some viruses can be carried by mosquitoes in Tasmania, other viruses are only carried by mosquitoes in other states or territories, or overseas.
It is important to take steps to protect yourself and your family from mosquito-borne diseases by avoiding mosquito bites and removing mosquito breeding sites. This is especially important in the warmer months in Tasmania and when travelling interstate or overseas. Ross River virus and Barmah Forest virus are present in Tasmania.
In recent years, people have contracted serious mosquito-borne diseases in parts of Australia where they don’t usually occur, such as Japanese encephalitis virus in South Eastern Australia. There have also been recent reports of Murray Valley encephalitis.
Mosquito borne diseases are notifiable to the Tasmanian Department of Health, see the Guidelines for Notifying Diseases and Food Contaminants. There is also a mosquito surveillance program underway in Tasmania.
Take action to protect yourself and reduce your risk
Protect yourself
- Wear covered footwear and loose-fitting, light-coloured clothing that covers as much of your body as possible. Mosquitoes can bite through tight-fitting clothing.
- Use insect repellents containing DEET (Diethyl toluamide), Picaridin or oil of lemon eucalyptus (OLE) on exposed skin. Always read the manufacturer's instructions before applying.
- Take extra care when mosquitoes are more active, especially around dawn and dusk and when outdoors or camping.
- Use ‘knockdown’ fly sprays and plug-in repellent devices indoors.
- Use mosquito coils in outdoor areas where you gather to sit or eat.
- Remove potential mosquito breeding sites from around the home (for example containers that collect water).
- Use insect screens on your house, caravan or tent. If this is not possible, use a mosquito net.
Reduce your risk
- Stay in rooms with insect screens or in air-conditioned rooms.
- Use a mosquito net over your bed if the area where you are sleeping is exposed to the outdoors. Nets are most effective when they are treated with a pyrethroid insecticide, such as permethrin.
- Stay up-to-date with local health guidance on mosquito-borne diseases at your travel destination and consider getting travel vaccines if recommended.
Mosquito-borne diseases that occur in Tasmania
Ross River virus and Barmah Forest virus
Ross River virus and Barmah Forest virus are infections spread by the bite of an infected mosquito.
These viruses are related and cause a similar illness.
Ross River virus is mostly acquired during the summer months when the weather is warmer and mosquitoes are more active. Outbreaks can occur when local conditions of rainfall, tides and temperature promote mosquito breeding.
Barmah Forest virus is relatively common in mainland states. It has only recently become present in Tasmania.
Ross River virus can be found in coastal regions extending from the North (including the islands of eastern Bass Strait), down to the south-eastern corner of Tasmania.
Find out more about Ross River virus and Barmah Forest virus
Mosquito-borne diseases that occur interstate or overseas
Japanese encephalitis
Japanese encephalitis is a rare but potentially serious infection of the brain caused by the Japanese encephalitis virus (JEV). It is a nationally notifiable disease.
JEV is spread by some types of mosquitoes and is more common in areas of increased mosquito activity. Pigs and certain water birds are hosts for the virus. There is no evidence of person-to-person transmission.
Most people infected with JEV have no symptoms. Very rarely JEVcan be serious and brain inflammation (encephalitis) can occur.
No cases have been detected in Tasmania.
The risk of being infected with JEV in Tasmania is currently very low.
In 2022, cases of Japanese Encephalitis occurred in south-eastern Australia, particularly along the Murray River at the NSW-VIC border. Most cases had extensive exposure to mosquitos or water-based activities prior to getting sick.
Japanese encephalitis virus is a vaccine preventable disease.
Find out more about Japanese Encephalitis virus
Murray Valley encephalitis
Murray Valley encephalitis is a potentially serious infection closely related to Japanese encephalitis. It is a nationally notifiable disease.
There have been recent cases of Murray Valley encephalitis infections in mainland Australia, some of these infections have resulted in serious illness and death.
Murray Valley encephalitis is spread through the bite of infected mosquitoes. Water birds are the primary host for the virus. Person-to-person transmission does not occur.
The mosquito primarily involved in transmitting Murray Valley encephalitis Virus is C. annulirostris. This mosquito is not currently found in Tasmania.
Find out more about Murray Valley encephalitis
Other mosquito-borne diseases
Interstate and overseas travel
If you're travelling interstate check out each Australian state and territory Department of Health website:
If you're travelling overseas, visit Smartraveller.go.au for health information on specific destinations.
Where to get help
- In an emergency call 000 (triple zero) for an ambulance
- Visit your nearest hospital emergency department
- Speak to your General Practitioner or for after hours see know your treatment options.
- For other queries, contact the Communicable Diseases Prevention Unit on 1800 671 738 (option 3 to speak to a Communicable Diseases Clinical Nurse Consultant) or via fax (03) 6173 0821.
