Queensland has recorded a fourth human case of Japanese encephalitis, taking Australia's total number of known or probable cases to 32.

Queensland Health had listed four virus cases as of Monday, but the latest case wasn't widely publicised like previous cases.

The patient has been listed in Brisbane's Metro North Hospital and Health Service for the week starting March 7.

Another human Japanese encephalitis case has also been listed in that region, while two are listed in the state's southwest.

Queensland Health did not comment on the new case or about the condition of the state's four Japanese encephalitis cases, but stressed that people should not be alarmed by the mosquito-borne virus.

"It's important to be vigilant, but not alarmed, by recent cases of Japanese encephalitis," a spokesperson said on Friday.

"Most people infected by Japanese encephalitis virus will experience mild symptoms, such as a headache and fever. Only in rare cases will JEV can cause serious illness."

"Given recent flooding, it is expected mosquito numbers will increase across Queensland.

"Queenslanders are urged to protect themselves by taking steps to avoid getting bitten by mosquitoes and removing mosquito breeding sites on their properties."

Australia has 32 confirmed or probable Japanese encephalitis cases in humans: 11 in Victoria, nine in NSW, eight in South Australia and four in Queensland.

One case in NSW, another in Victoria and a third in SA have been fatal.

The virus is spread by mosquitoes and can infect animals and humans. However, it can't be spread from person to person or by eating animal products.

About 99 per cent of cases are asymptomatic but some people may experience fever and headache.

One per cent could experience severe infection including convulsions, paralysis, neck stiffness, tremors and coma.

Children aged under five and the elderly are more likely to develop severe infection.

The virus, which has no specific treatment, can cause severe neurological illness, with headache, convulsions and reduced consciousness in some cases.

The discovery of the virus outside Australia's far north has alarmed experts. The last confirmed locally acquired human cases were recorded in the region in 1998.

The federal government has announced a $69 million plan to combat the spread of the disease, including the acquisition of another 130,000 vaccine doses.

A $5 million public information and awareness campaign will be launched, while $3.5 million will assist human testing.

To understand the spread, the government will enhance surveillance of mosquito and animal activities, model potential virus spread and undertake mosquito control.