Be alert for Japanese encephalitis
The natural lifecycle of Japanese encephalitis virus (JEV) is between waterbirds and mosquitoes, which can spill over to pigs and horses. It rarely infects other animals.
When there are mosquitoes around, there is a risk of mosquito-borne diseases. This increases in warmer, wetter weather, when mosquito numbers multiply.
Primary producers are strongly encouraged to:
- put measures in place to reduce the risk of mosquito bites
- watch for signs of JE in animals on their property.
JEV detections in SA
JEV was detected in South Australian commercial piggeries in early 2022. This followed confirmation of the virus at piggeries in Queensland, New South Wales, and Victoria. There have been no detections since then.
2021–22 financial year
JEV was detected in animals in the following local government areas:
| Local government area | Number of detections |
|---|---|
| Adelaide Plains | 1 |
| Clare and Gilbert Valleys | 1 |
| Coorong | 1 |
| Goyder | 1 |
| Light | 2 |
| Loxton Waikerie | 3 |
| Mid Murray | 1 |
| Murray Bridge | 1 |
Reduce risks of JEV
Transcript
[Text] Japanese encephalitis in South Australia – reduce the risk
[Mary Carr] Hi, I'm Dr Mary Carr, Chief Veterinary Officer for South Australia. I'd like to share some information with you about a mosquito-borne disease called Japanese encephalitis. I want to tell you what to look out for in your pigs and horses and what you need to do.
[Text] What are the signs of Japanese encephalitis in animals?
[Mary Carr] Common symptoms in pigs include mummified, stillborn, abnormal, or weak piglets. Live piglets may display neurological signs including paddling, tremors, or convulsions. Young piglets may also exhibit depression, wasting, or hind limb paralysis.
Boars may occasionally experience infertility fluid retention and congested testicles. Adult female pigs do not typically show signs of disease.
Most horses infected with JE show no signs when infected but very rarely the brain gets inflamed and neurological signs are seen. Common symptoms in horses to look out for include an elevated temperature, lethargy, decreased or no appetite, difficulty swallowing, impaired vision and jaundice. There may also be neurological signs like wobbliness, incoordination and rarely hyper-excitability.
Most cases showing symptoms are mild. However severe encephalitis can cause a severe disease requiring euthanasia.
Be on your alert and call your vet if you are worried.
[Text] What can I do to reduce the risk?
[Mary Carr] There are three things to remember: control, protect, report.
Control mosquitoes on your property. Eliminate mosquito breeding areas like stagnant water. Fill up puddles with soil. Tip out containers where mosquitoes could breed.
Protect your animals and yourself from mosquito bites. Cover your animals or keep them indoors at times of high mosquito activity like dusk and dawn. Using mosquito repellent or netting is recommended where possible. Protect yourself, too, not just your animals.
Make sure you follow the advice on using chemicals.
You'll find more information on our website and lastly report, if you suspect JE call 1800 675 888.
Arbovirus and mosquito monitoring reports
PIRSA collaborates with SA Health to understand the risk posed by arboviruses to both animals and humans.
SA Health is the lead control agency in the state for human disease epidemics, including outbreaks of serious human arboviral disease. They work with local councils, as relevant public health authorities for their areas, to support arbovirus prevention and mosquito surveillance and control programs.
See the SA Health arbovirus and mosquito monitoring reports.