Japanese encephalitis virus (JEV) is a nationally notifiable animal disease which means if you suspect an animal is showing signs of the disease, you must report it.
You can do this by contacting your local veterinarian or call the national Emergency Animal Disease Hotline on 1800 675 888. This will put you in touch with your state or territory’s agriculture department.
JEV is a viral disease spread by mosquitoes. JEV can cause reproductive losses and encephalitis in pigs and horses, and in rare cases can cause disease in humans.
In 2022, an outbreak of JEV in southern Australian states occurred in over 80 piggeries in Queensland, New South Wales, Victoria and South Australia.
JEV is now considered established in some parts of mainland Australia. It is expected to occur seasonally when there is increased mosquito activity in warm weather, particularly between October and April. Detections could occur year-round in the tropical north.
Information about detections of JEV in each state and territory can be found on the respective state and territory agriculture and health department websites.
Protect your animals
No matter where you are in Australia, it’s important to protect yourself and your animals from mosquito bites.
Guidelines are available for pig producers and horse owners to help protect animals from mosquito bites and reduce the risk of infection.
Suspected cases of JEV in animals must be reported immediately to the Emergency Animal Disease Hotline on 1800 675 888.
Signs of JEV in pigs
In pigs, the most common signs are mummified and stillborn or weak piglets, some with neurological signs.
Piglets infected after birth can develop encephalitis, which presents as paddling, or other neurological signs in the first six months of life. In other cases, wasting, depression or hindlimb paralysis may be seen in suckling piglets and weaners.
Adult sows do not typically show overt signs of disease. If boars are present on farm, they may experience infertility and swollen and congested testicles.
Signs of JEV in horses
Signs in horses are usually mild. Signs of the disease include:
- high temperature
- jaundice
- lethargy
- anorexia
- neurological signs which can vary in severity, including incoordination, difficulty swallowing, impaired vision, and over excitement.
While horses are a dead-end host of JEV, meaning they cannot spread the infection further, the disease may present similarly in horses to diseases that can spread directly to humans, including Hendra virus. Because of this risk, it is important to take precautions and use personal protective equipment (PPE) as directed by your veterinarian, if caring for a sick horse and/or while waiting for test results.
Human health
People can become infected with JEV through the bite of an infected mosquito. JEV cannot be transmitted between humans, and humans cannot catch JEV from infected animals.
Japanese encephalitis is not a food safety concern and commercially produced pork meat or products are safe to consume.
Information on reducing risks to people is available from the Department of Health and Aged Care.
State and territory public health JEV vaccination programs are in place. Information on who is eligible and how to receive a JEV vaccine is available from your state or territory public health authority.
Watch
In this video Dr Mark Schipp, Australia’s recently retired Chief Veterinary Officer, discusses the key information about Japanese encephalitis virus, including its impacts on our life, economy and measures to stay safe from JEV.
Japanese encephalitis virus is a disease that’s spread by mosquitoes and can infect waterbirds, pigs, horses and on rare occasions, humans.
The virus has been detected in Australia in piggeries across several states, including Queensland, Victoria, New South Wales and South Australia.
It is important to know, that Japanese encephalitis is not a food safety concern and commercially produced pork products are safe to eat.
In pigs, the virus can cause reproductive losses, paralysis and wasting disease in piglets.
In horses and people, it can cause encephalitis or swelling of the brain.
Animals and people can only become infected through the bite of a mosquito that is carrying the virus, and the virus doesn’t spread directly between animals and people.
To stop the spread of Japanese encephalitis virus, the most important action to protect people and animals against the mosquito bites is to apply insecticides.
Blankets and covers on horses are also a good deterrent.
People who live or work near river systems should be vigilant, particularly piggery workers.
And we’re also monitoring whether the feral pig population is contributing to the outbreak.
Human vaccines are available and are prioritised for people working in the pig industry.
And while vaccines haven’t yet been approved for pigs in Australia, they’re available for horses to meet export requirements.
If you suspect your animal is showing signs of Japanese encephalitis virus, you must report it.
You can do this by contacting your local veterinarian or simply call the national Emergency Animal Disease Hotline on 1800 675 888.
For the latest information or to report an outbreak, please visit the Australian Government website: outbreak.gov.au
In 2022, Japanese encephalitis virus was detected in eastern and southern parts of Australia.
Mosquitoes carry the virus from infected waterbirds.
The disease is spread by mosquitoes and can infect pigs.
A mosquito infected with the virus can transmit it to a pig through its bite.
Japanese encephalitis can cause stillborn or weak piglets and deformities in piglets up to six months old.
It can also cause infertility in boars.
Once a pig has Japanese encephalitis, it can transmit the virus to other mosquitoes and those mosquitoes can pass it on to more pigs.
Pigs cannot pass the virus to humans or other animals.
Only an infected mosquito can transmit the virus to a person.
But humans are known as “dead end” hosts and cannot transmit the virus back to mosquitoes, other people, or animals.
Horses are also “dead end” hosts and cannot pass the virus on to mosquitoes, people, or other animals.
Find out more about the symptoms of Japanese encephalitis and how to keep mosquitoes under control on your property.
Visit agriculture.gov.au/jev