On this page
- In Victoria, the most common pathogens transmitted from mosquitoes to humans are viruses such as Ross River virus and Barmah Forest virus
- Infections caused by Japanese encephalitis virus, Murray Valley encephalitis virus and Kunjin virus are rare, but do have the potential to cause severe disease.
- Avoiding mosquito bites is the most important way to prevent mosquito-borne diseases.
- Mosquito management is the responsibility of all landowners or land occupiers.
About mosquito-borne diseases
More than 275 species of mosquitoes are found in Australia. Fortunately, only a few species bite humans, and fewer still are vectors of human diseases.
All mosquito-borne diseases are notifiable to the department. For information on notification requirements and procedures, see Notifiable infectious diseases, conditions and micro-organisms
Other mosquito-borne diseases reported in Victoria are those acquired interstate or overseas (such as dengue fever).
The most effective way to reduce your risk of mosquito-borne diseases is by avoiding mosquito bites and removing mosquito breeding sites around your home.
For more information on how to avoid mosquito bites, see Mosquitoes can carry on the Better Health Channel.
Mosquito-borne diseases in Victoria
Japanese encephalitis (JE) is a rare but potentially serious infection of the brain that can be spread to humans through mosquito bites. There are currently no reported cases of Japanese encephalitis in Victoria.
More information on JE
- Japanese encephalitis virus information for health professionals.
- Latest CHO Advisory - Health warning on Japanese encephalitis.
- Japanese encephalitis information for the .
Other resources for health professionals
Barmah Forest virus disease is caused by an alphavirus, which is spread by mosquitoes. Symptoms usually begin to appear between 7 to 10 (but up to 21) days after becoming infected, however many people infected with the virus do not develop any symptoms. Barmah Forest virus disease can cause joint inflammation and pain, fatigue and a rash of variable appearance.
Ross River virus disease is caused by an alphavirus, which is spread by mosquitoes. Symptoms usually begin to appear 3 to 9 (but up to 21) days after becoming infected, and can include joint inflammation and pain, fatigue, muscle aches and a rash.
- Information for health professionals about Ross River virus disease.
- Latest CHO Advisory - Health warning on mosquitoes and Ross River virus in Victorian coastal and inland riverine areas.
- Information for the public about Ross River virus .
- Factsheet - Ross River virus and Barmah Forest virus: the facts.
Murray Valley encephalitis is a rare but serious illness caused by a flavivirus. Symptoms usually begin to appear between 7 to 12 days after becoming infected. Most people don’t have any symptoms, while others may develop a mild illness and make a full recovery. Murray Valley encephalitis can lead to brain damage or death in severe cases.
Dengue virus disease (dengue fever) is a viral disease spready by mosquitoes in many tropical and subtropical parts of the world, including Africa, Asia, South America, and occasionally some parts of northern Queensland.
Dengue fever ranges in severity from a mild flu-like illness through to a severe disease, and classically presents as an acute febrile illness of sudden onset. There is no specific treatment and no vaccine. Early diagnosis and management of symptoms is critical to reduce the risk of complications and avoid further spread of the virus.
Mosquito management in Victoria
Since 1974, the Victorian Government has worked with other agencies including selected local governments to deliver an integrated mosquito management program.
This includes surveillance activities to monitor mosquito species and numbers and to test mosquitoes for viruses. Integrated mosquito management also includes mosquito control, investigation of mosquito-borne diseases in humans, and community education to reduce mosquito bites.
For more information visit Mosquito management in .
Roles and responsibilities for mosquito control
In Victoria, the Public Health and Wellbeing Regulations 2019 (the Regulations) outline responsibilities for mosquito management. Mosquito management is the responsibility of all landowners or land occupiers. This applies to land owned/managed by both the public sector or government, or private residents, businesses and organisations.
For further information on the roles and responsibilities of the Department of Health, local councils and public sector and private landowners and land occupiers, see Vector-borne infectious disease control - Changes to the Public Health and Wellbeing Regulations below.
Funding to local councils
The Victorian Government provides funding to councils in areas at high-risk for mosquito-borne diseases to undertake mosquito surveillance and support mosquito management.
It is up to each council to determine the mosquito management measures best suited to their needs, but the focus is on reducing the risk of spread of mosquito-borne diseases, including Ross River virus, Japanese encephalitis virus and Murray Valley encephalitis virus. Activities generally include trapping adult mosquitoes and vector control.
Changes to the Public Health and Wellbeing Regulations
On 14 December 2019, the Public Health and Wellbeing Regulations 2019 (the regulations) replaced the Public Health and Wellbeing Regulations 2009.
The new regulations will help reduce the risk of vector-borne diseases by broadening the scope of the existing regulations. They allow for the control of emerging and potential vector-borne disease risks.
For further information, see:
Mosquito surveillance report
The department conducts mosquito surveillance throughout the Victorian mosquito breeding season, which in inland areas typically occurs from early November through to late April the following year, with coastal areas typically starting earlier and ending later.
This report contains a range of indicators relating to mosquito-borne diseases actively monitored by the Department of Health (the department).
The indicators used in this report are sourced from the following surveillance systems:
- Human surveillance (notified confirmed and probable cases and/or modelled predictions of vector-borne disease)
- Mosquito surveillance (adult mosquitoes)
For more information, see Mosquito surveillance report.
Mosquito viral detections
As part of the mosquito surveillance program, captured mosquitoes are tested for Ross River virus (RRV), Barmah Forest Virus, Murray Valley encephalitis virus (MVEV), Japanese encephalitis virus (JEV) and West Nile/Kunjin virus. Table 1 lists all viral detections in mosquitoes for the 2022/2023 season.
The timing of detections of virus may be influenced by access to traps, transport of specimens, laboratory capacity and other factors. The accuracy of testing may be impacted by the number and location of traps, the number, type and condition of captured mosquitoes, as well as other factors. Note that virus may be circulating in Local Government Areas (LGAs) that are not listed as surveillance is only conducted on a sample of the overall mosquito population.
Viral detections in trapped mosquitoes for the 2022/2023 season by LGA
Trap collection date Notification date Virus detected 29/11/2022 6/12/2022 BFV 7/12/2022 16/12/2022 BFV 7/12/2022 16/12/2022 BFV 20/12/2022 22/12/2022 RRV 21/12/2022 29/12/2022 RRV 17/01/2023 24/01/2023 MVEV 17/01/2023 24/01/2023 RRV 24/01/2023 27/01/2023 MVEV 31/01/2023 3/02/2023 MVEV
Trap collection date Notification date Virus detected 6/12/2022 9/12/2022 BFV
Trap collection date Notification date Virus detected 10/01/2023 13/01/2023 BFV
Trap collection date Notification date Virus detected 20/12/2022 22/12/2022 RRV 5/01/2023 10/01/2023 RRV 5/01/2023 10/01/2023 MVEV 17/01/2023 20/01/2023 RRV
Trap collection date Notification date Virus detected 17/01/2023 24/01/2023 MVEV 24/01/2023 31/01/2023 MVEV 7/02/2023 10/02/2023 MVEV
Trap collection date Notification date Virus detected 30/11/2022 9/12/2022 RRV 30/12/2022 10/01/2023 RRV 24/01/2023 31/01/2023 MVEV
Trap collection date Notification date Virus detected 10/01/2023 13/01/2023 MVEV 10/01/2023 13/01/2023 RRV 18/01/2023 24/01/2023 MVEV 18/01/2023 24/01/2023 MVEV 17/01/2023 27/01/2023 MVEV 24/01/2023 27/01/2023 MVEV 24/01/2023 7/02/2023 MVEV 24/01/2023 7/02/2023 MVEV 15/02/2023 21/02/2023 MVEV
Trap collection date Notification date Virus detected 29/11/2022 6/12/2022 BFV 20/12/2022 6/01/2023 RRV 4/01/2023 6/01/2023 RRV 4/01/2023 6/01/2023 RRV 20/12/2022 6/01/2023 BFV 10/01/2023 13/01/2023 MVEV 17/01/2023 20/01/2023 MVEV 17/01/2023 20/01/2023 MVEV 24/01/2023 27/01/2023 MVEV 31/01/2023 7/02/2023 MVEV 7/02/2023 10/02/2023 WNV/Kunjin
Trap collection date Notification date Virus detected 6/12/2022 13/12/2022 BFV 20/12/2022 22/12/2022 RRV 20/12/2022 22/12/2022 BFV 28/12/2022 4/01/2023 RRV 4/01/2023 10/01/2023 RRV 4/01/2023 10/01/2023 MVEV 10/01/2023 13/01/2023 MVEV 10/01/2023 13/01/2023 MVEV 17/01/2023 20/01/2023 WNV/Kunjin 17/01/2023 20/01/2023 WNV/Kunjin 17/01/2023 20/01/2023 WNV/Kunjin 17/01/2023 20/01/2023 MVEV 17/01/2023 20/01/2023 MVEV 17/01/2023 20/01/2023 MVEV 17/01/2023 20/01/2023 MVEV 17/01/2023 20/01/2023 MVEV 17/01/2023 20/01/2023 MVEV 17/01/2023 20/01/2023 RRV 24/01/2023 27/01/2023 WNV/Kunjin 24/01/2023 27/01/2023 MVEV 24/01/2023 27/01/2023 MVEV 24/01/2023 27/01/2023 MVEV 31/01/2023 3/02/2023 MVEV 31/01/2023 3/02/2023 MVEV 31/01/2023 3/02/2023 MVEV 31/01/2023 3/02/2023 WNV/Kunjin 31/01/2023 3/02/2023 WNV/Kunjin 7/02/2023 10/02/2023 MVEV 7/02/2023 10/02/2023 MVEV 14/02/2023 17/02/2023 MVEV 21/02/2023 24/02/2023 MVEV 21/02/2023 24/02/2023 MVEV 21/02/2023 24/02/2023 MVEV 3/7/2023 3/10/2023 MVEV 3/7/2023 3/10/2023 MVEV
Trap collection date Notification date Virus detected 20/12/2022 29/12/2022 BFV 20/12/2022 29/12/2022 BFV 4/01/2023 6/01/2023 RRV 7/02/2023 14/02/2023 MVEV
Trap collection date Notification date Virus detected 3/01/2023 6/01/2023 RRV 17/01/2023 20/01/2023 RRV 12/30/2022 3/3/2023 RRV 12/30/2022 3/3/2023 RRV
Trap collection date Notification date Virus detected 11/01/2023 18/01/2023 WNV/Kunjin 24/01/2023 3/02/2023 MVEV
Reviewed 17 March 2023