Japanese Encephalitis (JE) in Victoria

The Japanese Encephalitis (JE) virus was detected in Victoria for the first time in February 2022. JE virus was initially detected in pigs, and locally acquired human cases of JE ,and virus detections in mosquitoes were subsequently identified. A comprehensive response across human and animal health sectors has been implemented following the first detections of the virus in Victoria and is ongoing.

Who is at risk?

People aged 2 months or older who live or routinely work in any of the following local government areas of Campaspe, Gannawarra, Greater Shepparton, Indigo, Loddon, Mildura, Moira, Swan Hill, Wodonga, Towong, Benalla, Wangaratta, Strathbogie, Buloke, Greater Bendigo, Hindmarsh, Horsham, Northern Grampians, West Wimmera and Yarriambiack AND:

• regularly spend time engaging in outdoor activities that place them as risk of mosquito bites, OR
• are experiencing homelessness, OR
• are living in conditions with limited mosquito protection (e.g. tents, caravans, dwellings with no insect screens), OR
• are engaging in outdoor flood recovery (clean-up) efforts, including repeated professional or volunteer deployments.*

*Vaccination can be administered before arrival in flood affected areas to those from other regions deployed for recovery efforts by arrangement.

The risk of exposure to mosquitoes is low at an elevation of greater than 500 metres. Therefore, JE vaccination is only recommended for individuals who spend significant time outdoors below this elevation in these local government areas.

Symptoms and treatment

Most JE virus infections are asymptomatic. However, less than one per cent of the population may develop inflammation of the brain called encephalitis, which can lead to coma, permanent disability or death.

Symptoms of encephalitis include:

• fever
• headache
• convulsions
• neck or back stiffness
• sensitivity to light
• vomiting
• confusion.

Usually, symptoms will develop 6 to 16 days after being bitten by an infected mosquito. Anyone experiencing these symptoms – particularly if they’ve visited northern and north-west Victoria, the Murray River and its surrounds, or been in contact with pigs – should seek urgent medical attention.

There is no specific treatment available for JE virus. For those with symptoms, treatment aims to reduce the severity of the symptoms and may include medication and hospitalisation.

Prevention

Avoiding mosquito bites and removing mosquito breeding sites around your home and property is critical to the prevention of JE virus.

People should take steps to limit their exposure to mosquitoes by:

• Wearing long, loose fitting clothes outdoors.
• Using mosquito repellents containing picaridin or DEET on all exposed skin.
• Limiting outdoor activity if lots of mosquitoes are about.
• Using ‘knockdown’ fly sprays and plug-in repellent devices indoors.
• Sleeping 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 or out in the open.

More information about prevention can be found at Beat the Bite!, including tips to mosquito-proof your home and tips for people going on holidays. 

Vaccination

A Japanese Encephalitis vaccine is available and is recommended for people who may be at increased risk, including those who may have occupational exposure to the virus.

People listed in the specific priority groups are advised to contact their general practitioner, local public health unit, local council or community pharmacy for more information.

Please note, while the vaccine is free-of-charge, some providers may charge an administration or consultation fee. Be sure to check if this applies to you.

Speak to your GP about whether the JE vaccine is appropriate for you. More information about vaccination can be found on the Department of Health JE page  .

Further information for clinicians

The following links contain further informationa and resources for clinicians:

Department of Health - Japanese Encephalitis information for professionals  
CDC - Japanese Encephalitis information centre 

To keep up-to-date with the latest information on JE in Victoria, subscribe to Victorian Health Alerts and Advisories.