March,  2022

Industry Notice

Japanese encephalitis found
in Southern Queensland

Biosecurity Queensland has released a biosecurity notice following the detection of Japanese encephalitis at a commercial piggery in southern Queensland. 

The disease has also been detected in piggeries in New South Wales and Victoria.

Japanese encephalitis is a mosquito-borne viral disease with a natural transmission cycle in waterbirds. 

Disease can occur in pigs and horses when bitten by infected mosquitoes.

Direct horse-to horse or horse-to-human transmission does not occur.

In horses, the disease is usually mild with symptoms including fever, lethargy and decreased appetite.  Jaundice and neurological (nervous) signs, such as incoordination or difficulty swallowing, may develop in some cases.  

Occasionally, severe neurological signs such as hyperexcitation, muscle tremors, profuse sweating and blindness may occur.

Steps that can be taken to reduce the risk of exposure of horses to mosquitos include:

• using physical barriers such as light rugs and hoods during peak periods of mosquito activity (between dusk and dawn).
• reducing mosquito breeding sites on the premises by removing standing water.
• using fans and automatic overhead misting systems to reduce mosquito numbers in stables.
• using mosquito repellents; and
• if possible, housing horses in mosquito-screened stables.

Recent heavy rains and higher than average rainfall provide ideal conditions for mosquitos to breed.

For more information about Japanese encephalitis in animals see the Business Queensland website.

Japanese encephalitis virus can also cause disease in people. 
For more information about Japanese Encephalitis in people see the Queensland Health website.