The first active cases of Japanese Encephalitis (JEV) have been detected in the Northern Territory, after a small number of feral pigs in the West Daly region have tested positive to the virus.
JEV is a serious disease spread through mosquitoes, which can infect humans and animals, including pigs, birds and horses.
The virus has been spreading throughout piggeries in southern parts of Australia since February and 35 cases have been confirmed in humans to date, leading to the deaths of three people.
NT's chief veterinary officer, Sue Fitzpatrick, said there had been no cases recorded in the territory since a person in the Tiwi Islands died with the virus in March last year.
Since then, the Northern Territory has increased its surveillance program in its animal population.
Dr Fitzpatrick said the virus was detected "during a routine survey" in the West Daly and the pigs were asymptomatic.
"While there was evidence of [JEV] exposure last wet season, we haven't been able to detect any active infection until this, the feral pigs in the West Daly region," Dr Fitzpatrick said.
To date, all mosquito samples tested in NT have been negative for JEV.
NT Health urges territorians to 'stay vigilant'
Nina Kurucz, director of NT Health's medical entomology unit, said JEV couldn't be transmitted from human to human, or by eating meat from an infected animal.
"JE infection in humans is most commonly asymptomatic but, on rare occasions, it can result in severe disease and even death," she said.
"Symptoms can include fever, headache, neck stiffness, vomiting, confusion, seizures and paralysis."
Dr Kurucz urged territorians to stay vigilant and take precautions against mosquito bites.
Dr Fitzpatrick said it was also important for people to understand the potential risk for their animals.
She said the main animals infected were pigs and horses.
Dr Fitzpatrick said although horses could be infected, they had low virus levels in their blood so "were not a risk to other people".
However, she said the virus could kill horses, and symptoms presented as "nervous or neurological signs".
Pig owners should be "highly vigilant" for signs of the disease, Dr Fitzpatrick said, and should report any "unexplained pig miscarriages or stillbirths or neurological signs in young piglets".
She said pigs presented a higher risk for transmission, so owners should "take steps" to control mosquitoes around pig pens.
"If they are infected, they can have quite large viral loads in their blood and when the mosquito bites the pig, they can then infect another person or another animal," Dr Fitzpatrick said.
Animal owners and hunters can report suspicious or unusual signs in animals to the Emergency Animal Disease Watch hotline on 1800 675 888.
There is no specific treatment for the virus, but vaccination is available.
