Japanese encephalitis virus in Australia (Queensland & New South Wales)

Health authorities in Australia have issued a public health alert following a confirmed human case of Japanese encephalitis in Queensland. The virus has also been found recently in pigs on farms in New South Wales, with people in both states being advised to avoid mosquito bites.

Japanese encephalitis is a mosquito-borne virus which affects the central nervous system, most common around areas of rice and pig farming. It is transmitted from animals, mainly pigs and 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 ten years of age or older than 50

For most travellers the risk of acquiring infection is very small, but practitioners should consider vaccinating:

• those likely to be frequently exposed to mosquito bites in rural infected areas, such as backpackers, agricultural workers, volunteers
• long stays, of more than one month, in infected areas
• repeated visits to risk areas such as flood plains, rice paddies, and marshlands
• short stays during epidemics and outbreaks
• migrants going to live in an endemic area

Information and advice for travellers on Japanese encephalitis is available from the TRAVAX (for health professionals) and fitfortravel (for the general public) websites.

Source: TRAVAX, 3 March 2022