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Barwon Health / Barwon South West Public Health Unit

(03) 4215 4000

Disease spotlight - Japanese Encephalitis

Tuesday, 21 June 2022

Globally throughout the COVID-19 pandemic, the discussion and understanding of public health and infectious diseases have become an important part of everyday life.

As we learn to live with COVID-19, the Barwon South West Public Health Unit (BSWPHU) continues to monitor and manage COVID-9 outbreaks along with a number of other infectious diseases such as ross river virus (RRV), Buruli Ulcer and Japanese Encephalitis Virus (JEV).

Here Dr Naomi Clarke, Public Health Registrar at the BSWPHU talks about JEV and the work the team are doing to monitor this disease in the Barwon South West region.

What is JE Virus? (Symptoms, treatment, etc)

Japanese encephalitis (JE) virus is a virus that can infect humans. The majority of people who are infected with the JE virus have no symptoms. Some people may have a mild illness with symptoms such as fever and headache.

In a small proportion of people (less than 1% of those infection) it causes encephalitis, which is an infection of the brain that can lead to death or permanent disability. Symptoms of encephalitis include fever, headache, seizures (convulsions), confusion and reduced consciousness.

There is no specific treatment available for JE. People with encephalitis need to be admitted to hospital for treatment of their symptoms.

JE is known to exist throughout large parts of Asia and the Pacific. Prior to 2022, there had not been local transmission of the JE virus in Southern Australia.

How are people are infected?

 The only way humans can become infected is by being bitten by a mosquito that is carrying the JE virus. Mosquitoes can pick up the JE virus from infected pigs or water birds.

Humans cannot get the JE virus from direct contact with pigs, or from eating pork or pig products. The JE virus cannot be spread directly from person to person.

Who is at highest risk of getting JEV?

People most at risk of JE virus include people who live near or work with pigs, and people in the northern and north-west Victoria and along the Murray River. People with increased exposure to mosquitoes may be at a higher risk of infection, particularly people working or living on pig farms, people camping, or working or spending time outdoors in high risk areas.

What is happening with JEV in Australia?

The first pig and human JE virus cases in southern Australia were detected in February 2022. Since then, a number of JE virus cases have been detected in pigs and humans in Victoria (mainly along the Murray River) as well as in NSW, Queensland and South Australia.

There is currently a very low risk of JE virus in Victoria because the cold winter weather is not favourable for mosquitoes.

What can we do to prevent infection?

  • The best way to prevent infection is by avoiding mosquito bites, particularly in high risk areas such as along the Murray River. Simple steps that you can take to reduce risk of mosquito bites include:
    • 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.
    • Using mosquito coils in small outdoor areas where you gather to sit or eat.
    • Making sure your accommodation is mosquito-proof.
    • 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.
    • Making sure there is no stagnant water around your home.
  • There is also a vaccination available for JE. Currently, vaccination is available in Victoria free-of-charge for specific high-risk groups:
    • People who work at, reside at, or visit to a piggery, pork abattoir or pork rendering plant.
    • People who work with mosquitoes (e.g. in mosquito surveillance, control and management)
    • People who work in a laboratory and may be exposed to the virus

What is the BSWPHU team doing to manage this disease in our region?

 The BSWPHU team is working with the Department of Health to manage JE virus in our region. We have contacted many people who may be eligible for the JE vaccination, including local pig properties or mosquito control programs, to link them in with GPs who are providing the vaccination.

We are available to field enquiries from the public about the JE virus and the JE vaccination. D