Queensland has announced its first human case of Japanese encephalitis virus, as health officials investigate dozens of other potential cases across Australia.

On Thursday night, Queensland Health confirmed the infected person was being treated in a Brisbane hospital and had recently travelled to regional southern Queensland.

Overall, there are 16 cases of encephalitis “of unknown cause” under investigation across NSW, Victoria and South Australia, a federal Department of Health spokeswoman said.

It comes after Victorian health authorities confirmed four suspected cases of JEV, believed to be the first in southern Australia, connected to a piggery near Echuca in the state’s north.

All four were admitted to hospital and one has since been discharged.

Federal, state and territory authorities are meeting regularly to discuss next steps as the disease continues to spread.

Earlier this week, health warnings were issued in several states after the disease was found in one piggery in Victoria’s north, six piggeries in NSW and one in Queensland.

Japanese encephalitis virus spreads through mosquito bites and people in regional areas who are in contact with pigs may be at particular risk.

Two vaccinations are available for protection against JEV in Australia, with older people and those aged under five at a higher risk of developing a serious illness.

The disease is not transmitted from person to person and cannot be caught by eating pork or pig products.

Anyone who works with pigs or horses, even if they’re backyard pets, is urged to keep an eye out and report any possible signs of the disease.

People living in high mosquito areas encouraged to use repellent, containing picaridin or DEET, and cover up with loose-fitting clothing.

-AAP