Australia’s Chief Veterinary Officer has confirmed the Japanese encephalitis virus (JEV) has been detected in piggeries across several states, with two human deaths now reported.
In early March Mark Schipp said JEV has been diagnosed at one piggery in Victoria’s north, one piggery and Queensland and six piggeries in NSW, and cases have subsequently been confirmed in South Australia.
In late February a Victorian man in his 60s succumbed to the JEV outbreak, and this was followed by the death of a NSW man in his 70s on March 9.
“JEV is a mosquito-borne viral disease that mostly occurs in pigs and horses but can cause disease in people and rarely other animals,” he said.
“Animals and people become infected through the bite of infected mosquitoes.
“It cannot be caught through eating pork or pig products…the disease is not transmitted from person to person.”
Schipp said it is the first time the virus has been detected in southern Australia, with biosecurity authorities cooperating with human health departments to contain the exposure.
“The Department of Health and the Department of Agriculture, Water and the Environment are collaborating closely, together with state and territory counterparts.
“We are meeting regularly and working together to work through the next steps of this situation.
“We’re asking anyone who works with pigs or horses, even if they’re a pet in the backyard, to keep an eye out for and report any possible signs of this disease.”
Common symptoms in pigs are stillborn or mummified piglets, or piglets who display neurological issues in their first six months of life.
Adult boars can experience testicle congestion or infertility, while the disease tends to be asymptomatic in adult sows.
Schipp said that while most infected horses show no signs of JEV, indications of more severe cases include “fever, jaundice, lethargy, anorexia and neurological signs which can vary in severity.”
“JEV is a nationally notifiable disease, which means if you suspect an animal is showing signs of the disease, you must report it (and) measures should also be taken to protect animals from mosquitoes, for instance, applying a safe insect repellent and putting a summer rug on horses.”
Acting Chief Medical Officer Sonya Bennet said pigs are the focus from a human health perspective.
“They can infect mosquitoes who then infect humans, this is not the case with horses,” she said.
“Severe illness arising from JEV infections in humans is rare and most people will have no symptoms at all if infected.
“However, a very small proportion of people infected my develop a serious illness such as encephalitis and experience symptoms including neck stiffness, severe headache and come, and more rarely, permanent neurological complications or death.”
Bennett said that illness usually begins with symptoms such as a sudden onset of fever, headache, and vomiting.
She added that work has commenced to plan for targeted vaccinations, with two vaccines available for protection against JEV in Australia.
“However, prevention is always better than a cure and there are simple steps we can all take to avoid our exposure to infected mosquitos,” she said.
“People in areas of high mosquito activity in Eastern Australia should use mosquito repellent containing picaridin or DEET on all exposed skin (and) wear long, loose fitting clothing when outside, and ensure accommodation, including tents, are properly fitted with mosquito nettings or screens.”
JEV can be reported on the Emergency Animal Disease Watch Hotline on 1800 675 888.
SAM WORRAD