Japanese encephalitis in Australia

On 22 December 2022, the Government of New South Wales reported a case of Japanese encephalitis in a resident of Lake Cargelligo. This is the first case reported this summer.

Japanese encephalitis virus (JEV) is a mosquito-borne virus which affects the central nervous system. It is most common around areas of rice and pig farming. JEV is transmitted from animals (mainly pigs/birds) to humans through the bite of an infected Culex mosquito which feeds in the hours around dusk. No human-to human transmission occurs.

Advice for Travellers

All travellers to endemic countries or outbreak areas are potentially at risk of infection. This risk is greatest for those:

• travelling to rural areas during transmission seasons
• participating in outdoor activities during twilight hours
• travelling for a prolonged period of time

All travellers should be advised on:

• the risks and potentially severe consequences of Japanese encephalitis
• practicing strict mosquito bite avoidance measures, including correct use of insect repellents
• minimising outdoor activities during twilight hours when Culex mosquitoes bite

Travellers at increased risk of developing severe clinical disease are those:

• with pre-existing chronic medical conditions
• younger than 10 years of age
• older than 50 years of age

When to consider vaccination

For most travellers the risk of acquiring infection will be very small, but consider vaccinating those:

• frequently exposed to bites in rural infected areas (e.g. backpackers, agricultural workers, volunteers)
• at ongoing risk or repeatedly visiting 'high risk' areas (e.g. flood plains, rice paddies, marshlands, pig farms)
• staying for short periods during epidemics/outbreaks
• staying for long periods (e.g. more than one month) in infected areas
• going to live in an endemic area

For further information, see the Japanese Encephalitis page.