WA pork industry on alert as Japanese encephalitis spreads in the east, with one person in intensive care

WA’s pork industry is on high alert after a potentially deadly mosquito-borne virus infected more than 40 piggeries across Australia’s eastern seaboard and spread to South Australia within a matter of days.

The number of pig farms with confirmed cases of Japanese encephalitis increased from 14 on Friday to 42 as of Monday morning after Queensland recorded its first locally acquired human case in more than two decades.

The cases include 13 in NSW, one in Queensland, six in Victoria and one in South Australia.

Federal Agriculture Minister David Littleproud said vaccines were being distributed to high-risk areas to try to mitigate the “real threat” of the virus, which was declared a communicable disease incident of national significance.

A national working group of disease, vaccine and arbovirus experts has also been set up, with mosquito surveillance, control measures and a vaccine rollout on the way.

“The fact that it has effectively spread right across the eastern seaboard and into South Australia says that this is a real threat that we need to take seriously,” Mr Littleproud said.

“We already have a small quantity of vaccines for this here in Australia and they’ve been distributed.

“There’s been another tranche that has come in, there’ll be another one that will be brought in as well.”

Japanese encephalitis can cause severe neurological illness with headaches, convulsions and reduced consciousness in some cases.

It spreads by mosquitoes carrying it from either pigs or water birds, but it doesn’t transmit from animal to animal, or animal to human, or human to human.

NSW Health on Friday confirmed a person was in intensive care with a highly probable case of the virus.

Locally acquired cases had never previously been identified in NSW in animals or humans.

The eastern states’ detection sparked an urgent warning for WA pig producers to monitor stock for symptoms and manage mosquito numbers on their properties.

The warning also extends to horse owners, with farmers monitoring efforts supporting the Department of Primary Industries and Regional Development in ensuring early detection of the disease if it reaches WA.

WA Pork Producers Association president Graeme Dent said industry had been in regular contact with DPIRD and believed the virus had not yet entered WA.

“It is a concern because this is a mosquito-borne virus and so all pig sheds have got very good biosecurity, we are on top of that with African Swine Fever, and protecting ourselves, but this is something else,” he said.

“We are on top of it as well as we can be, we are being vigilant and telling our workers to wear appropriate clothing and mosquito repellent... and report anything out of the ordinary.

“This virus doesn’t like heat, we have had a very hot summer and we haven’t had any summer rain... so the amount of still water laying around is very minimal, and people are doing what they can to protect themselves.”

DPIRD biosecurity executive director Mia Carbon said while the risk to WA was low, it was important farmers were vigilant and reported any indications of the virus.

“Japanese encephalitis is a serious disease that can cause reproductive losses in pigs, as well as mild to severe disease in horses and donkeys,” Dr Carbon said.

“The disease is spread between pigs by the bite of an infected mosquito and cannot be directly spread from pigs to people.

“Pig owners should monitor and report any mummified, stillborn or weak piglets, as well as tremors and convulsions, which can occasionally occur in pigs up to six months of age.

“In most cases, Japanese encephalitis in horses is mild but owners should monitor and report any disease signs, including an elevated temperature, jaundice, lethargy, anorexia and neurological signs, such as incoordination, difficulty swallowing and impaired vision.”

The disease is not a food safety concern and pork and pig meat products are safe for human consumption.

The department is working with WA Department of Health, as well as interstate and national organisations, as part of a coordinated national response to the disease incident in the eastern states.

Dr Carbon said managing mosquitoes on properties would minimise potential human and animal exposure should Japanese encephalitis be detected within the State.

Suspect signs of Japanese encephalitis should be reported to a local private veterinarian, DPIRD veterinary officers or the national Emergency Animal Disease Watch Hotline on 1800 675 888.

To find out more, visit agric.wa.gov.au/japanese-encephalitis.