Feedback
Japanese encephalitis information for pig owners
In early 2022, Japanese encephalitis was detected in piggeries in Queensland, New South Wales, Victoria and South Australia.
Japanese encephalitis is category 1 restricted matter.
Under Queensland legislation, if you suspect the presence of this disease in any species of animal, you must report it to Biosecurity Queensland on 13 25 23 or contact the Emergency Animal Disease Hotline on 1800 675 888.
Japanese encephalitis is a mosquito-borne viral disease. Waterbirds act as natural reservoirs for the virus, and mosquitoes can spread the virus to people, horses, pigs and other animals.
Most infections with Japanese encephalitis virus (JEV) in pigs are subclinical, meaning the animal is infected but shows no signs of disease. However, during the 2022 outbreak significant impacts were seen with reports of up to 20% of piglets stillborn or mummified.
While it is unknown if JEV will continue to be detected in pigs in Queensland in the future, it is a serious zoonotic disease.
Queensland pig owners and operators of piggeries are urged to take steps to protect their pigs against JEV and remain alert for any signs of JEV infection in their animals. Work with your veterinarian if your animals are showing clinical signs and if JEV is suspected, report this to Biosecurity Queensland.
Reducing the risk of JEV in pigs
If you work with or have contact with pigs, including small herds or pets, you should take steps to control mosquitoes on your property and continue to use effective biosecurity measures.
You should have an effective mosquito management program in place that targets all stages of the mosquito life cycle using a combination of non-chemical and chemical methods.
This requires a combination of:
- environmental management to reduce mosquito breeding and resting sites
- treating the larvae (larviciding)
- treating the adults (adulticiding)
- ongoing monitoring and surveillance
- record keeping.
To reduce the risk of infection in your pigs:
- treat or remove potential mosquito breeding sites
- spray or fog the outside of sheds regularly with a handheld or commercial spray unit with approved insecticide
- disperse approved mosquito larvicides over water bodies close to sheds, that cannot be drained
- remove water lying around sheds and roads
- remove weeds and mow long grass
- monitor mosquito numbers daily. Inspect water bodies and water-filled containers for wrigglers and check facilities for resting adult mosquitoes (e.g. ceilings, walls). If mosquitoes remain abundant, consider additional mosquito control
- speak with your local council about their mosquito management timetable in your area. This can assist with your mosquito management planning for your property.
Seek professional advice about using chemicals to control mosquitoes. Chemicals for mosquito control should only be used by people authorised in accordance with Queensland training and licensing requirements.
Only use chemicals that are registered for use on pigs, pig feed, or surfaces pigs may contact. Ensure you use chemicals in a way that they do not drift onto pigs.
Read about mosquito control around piggeries.
Pig producers should also continue to use effective biosecurity measures in the National farm biosecurity manual for pork production (PDF, 3.1MB).
If you own or keep a pig in Queensland you must be registered as a biosecurity entity. Registration allows you to be kept informed in the event of a biosecurity emergency.
What to do if you suspect JEV in your pigs
Pig owners and people who manage pigs have a legal obligation, known as the general biosecurity obligation, to take all reasonable and practical measures to prevent or minimise the effects of a biosecurity risk.
Japanese encephalitis poses a serious biosecurity risk. This means pig owners are legally required to reduce the risk of JEV infection and limit the spread when dealing with pigs.
Who to contact if you suspect JEV
If you suspect JEV in your pigs, contact your private veterinarian immediately.
If your veterinarian believes your pigs may have JEV, they will take samples from your pigs and submit the samples for testing at a government laboratory. Initial test results are usually available 1 working day after the laboratory receives the samples.
What to do while waiting for test results
While you are waiting for laboratory test results, isolate pigs showing clinical signs consistent with JEV until you obtain the results.
Ensure you take steps to reduce the risk of people being infected.
If the results are negative for JEV, they will be reported to your veterinarian who may wish to take more samples to further investigate your pig's illness.
A Biosecurity Queensland officer will contact you if your test results indicate JEV infection in your pigs.
Read what happens if your pigs are infected with JEV.
What happens if your pigs are infected with JEV
If laboratory tests confirm the presence of JEV in your pigs, Biosecurity Queensland will work with you to manage the situation.
Your property will be identified as high-risk for JEV and you will need to implement risk mitigation strategies to minimise further cases of JEV.
Typically your property will not be placed under any movement restrictions; however, you have a legal obligation called your general biosecurity obligation to take all reasonable and practical measures to minimise the effects of JEV.
Property Management Plan
The measures you take will need to be documented in a Japanese encephalitis Property Management Plan (PMP). A Biosecurity Queensland officer will provide you with a copy of the PMP and discuss this with you.
The PMP has been specifically designed to support pig properties with JEV infection to meet their general biosecurity obligation to manage and undertake a risk assessment of JEV.
Your PMP will include actions aimed at:
- identifying human health risks and control options
- mosquito management
- ongoing disease surveillance and management
- understanding the risk in your pigs and how to manage them while continuing your business.
Contact your immediate neighbours to advise them of the JEV infection in your pigs. Often they will be exposed to the same mosquito burdens. By understanding the risk, they will be able to make informed decisions about how to manage the risk on their property.
Advise properties receiving pigs from your property, including abattoirs, that JEV infection has been confirmed in pigs on your property and inform the receiving property about how you are managing the risk.
Biosecurity Queensland will notify Queensland Health of the detected JEV infection in pigs and Queensland Health will contact you to provide information and support about human health including vaccination and mosquito management.
Biosecurity Queensland will assess the risk to other piggeries in the area and contact those piggeries if the risk is considered high.
Moving pigs with suspected JEV
Until you have received results from the laboratory tests, carefully consider whether you should move pigs from your property to other properties.
It is recommended that pigs showing clinical signs consistent with JEV should be isolated and remain on the property until you have received advice from your veterinarian or Biosecurity Queensland.
While the risk of spreading JEV infection by moving pigs is considered low, test results are usually available 1 day after the laboratory receives the sample. Waiting for the test results will give you and your veterinarian a better understanding of the risk.
You should advise properties receiving pigs from your property, including abattoirs, that you suspect (or have confirmed) JEV in pigs on your property and inform the receiving property about how you are managing the risk.
Other states or territories may have restrictions on pigs entering from a property where JEV infection has been confirmed. If you are moving pigs from Queensland interstate, it is your responsibility to be aware of and comply with any entry requirements.
Reducing the risk of people being infected
JEV is spread to people by the bite of an infected mosquito. Queenslanders, particularly those working with pigs, including feral pigs, are encouraged to take the necessary steps to prevent being bitten by mosquitoes.
To protect yourself:
- wear loose-fitting, long-sleeved shirt with long pants, and covered shoes
- use repellents that contain diethyltoluamide (DEET) or picaridin
- apply insect repellent on all exposed skin
- read the repellent label for reapplication times and re-apply accordingly
- consider using plug-in repellents and insect sprays.
Commercial piggeries can take additional steps to minimise the risk of infection in people by protecting workers, service providers and others at the property. This may include:
- ensuring accommodation, including tents, are properly fitted with mosquito nettings or screens
- considering using insecticide sprays, vapour dispensing units (indoors) and mosquito coils (outdoors)
- avoiding contact with bodily fluids and tissues of potentially infected animals. If this is not possible, ensure appropriate handling of potentially contaminated animals and use appropriate personal protective equipment such as masks, eye protection and gloves
- removing any standing water or water-holding containers on your property where mosquitoes could breed, wherever possible.
The Communicable Disease Network Australia has prioritised vaccination for people at a high-risk of exposure to JEV and recommends vaccination for some travellers.
If you have human health concerns, you should seek medical advice. Contact your general practitioner, local hospital emergency department or local public health unit, if you are concerned about possible Japanese encephalitis infection in people. Direct your general enquiries about Japanese encephalitis infection in people to Queensland Health on 13HEALTH (13 43 25 84). Read Queensland Health information about Japanese encephalitis and people.
For information about managing the risk of Japanese encephalitis in the workplace, contact Workplace Health and Safety Queensland on 1300 362 128.
Also consider...
- Learn facts about Japanese encephalitis and animals.
- Read about Japanese encephalitis and people from Queensland Health.
© The State of Queensland 1995–2024
- Last reviewed: 08 Sep 2021
- Last updated: 08 Sep 2021