Japanese encephalitis virus (JEV)

We are monitoring the unfolding situation in Australia concerning the Japanese encephalitis virus (JEV). It has been declared a Communicable Disease Incident of National Significance. We will update this alert with the latest medical advice and official reports.

Current status

For information about JEV and animals visit the Department of Agriculture, Water and the Environment website.

As at 24 February 2023:

There have been 45 human cases of JEV notified in Australia since 1 January 2021.

35 have been confirmed with definitive laboratory evidence:

  • New South Wales (14)
  • Northern Territory (2)
  • Queensland (2)
  • South Australia (6)
  • Victoria (11)

Please note: 1 previously confirmed case for Victoria was reclassified as Murray Valley Encephalitis virus infection.

10 are probable cases where the person has been linked epidemiologically and/or has symptoms of the disease and has laboratory suggestive evidence*:

  • Queensland (3)
  • South Australia (4)
  • Victoria (3)

* laboratory suggestive evidence is strongly indicative of JEV but cannot entirely rule out other related flaviviruses like Murray Valley Encephalitis (MVE).

Sadly, 7 people have been reported to have died as a result of JEV. Two in New South Wales, two in South Australia, one in Victoria, one in Queensland and one in the Northern Territory.

In January 2023, a revised national surveillance case definition was endorsed by the Communicable Diseases Network Australia (CDNA), which includes a probable case definition to enable the reporting of both probable and confirmed cases of JEV to the National Notifiable Diseases Surveillance System (NNDSS). The revised surveillance case definition was retrospectively applied from 1 January 2021 to capture all 2021–2022 outbreak cases. This has resulted in two historical cases from 2021 being included in the outbreak reporting.

Due to the dynamic nature of the database and active case investigations, reported data may vary from day to day based updates by states and territories. Cases diagnosed overseas are not reported to the database or included in Australian national case numbers.

Why is there an alert

Declaration of a Communicable Disease Incident of National Significance

On 4 March 2022, Australia’s Acting Chief Medical Officer, Dr Sonya Bennett, declared the Japanese encephalitis virus (JEV) situation a Communicable Disease Incident of National Significance. She determined a national approach was required in relation to coordination of health policy, interventions and public messaging.

The declaration was made under the Emergency Response Plan for Communicable Disease Incidents of National Significance, in consultation with the Australian Health Protection Principal Committee.

JEV is a nationally notifiable disease in both humans and animals.

What we are doing

The Australian Government’s health and agriculture departments have been are working very closely with state government counterparts to ensure a swift and coordinated response to JEV.

The human health response includes:

  • The JEV outbreak being declared a Communicable Disease Incident of National Significance (CDINS) on 4 March 2022
  • Engagement with experts, to develop/revise clinical guidance and support JEV testing, diagnosis and vaccination.
  • Enhanced surveillance and risk mapping to better understand the spread of JEV across Australia and potential risk of infection.
  • Delivery of a national Communications strategy, to raise awareness of the risks of JEV and importance of bite avoidance measures. Communications include targeted First Nations resources.
  • Ensuring access to vaccines via states and territories to those at greatest risk of infection.

Find out more

Visit our Japanese encephalitis virus (JEV) page and follow us on Facebook, Twitter and LinkedIn for updates.

Last updated:

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