SYDNEY (BLOOMBERG) - A mosquito-borne disease that can cause brain inflammation has emerged in Australia and infected at least one person, prompting officials to issue health alerts for people working with pigs and horses.

The confirmed Japanese encephalitis case in Queensland state, along with three suspected human infections in Victoria, follows the detection of the virus earlier in the week across multiple pork farms.

On Friday (March 4), the nation's health department declared the situation a Communicable Disease Incident of National Significance.

While serious sickness from the disease is rare and most people display no symptoms when infected, a small fraction may develop serious illness. There are up to 68,000 clinical cases of Japanese encephalitis detected globally each year, causing as many as 20,400 deaths, according to the World Health Organisation.

Most cases globally are concentrated in Southeast Asia and the Western Pacific regions, and some outbreaks have resulted in widespread pig culls. Australian Chief Veterinary Officer Mark Schipp said in a statement earlier this week that it's the first time the virus has been detected in southern Australia.

Queensland officials have confirmed a human case of Japanese encephalitis who is being treated in a Brisbane hospital, the nation's health department said in a statement on Friday. It said it was aware of other cases, in multiple states, of encephalitis of unknown origin that were being investigated for arboviral diseases, including Japanese encephalitis.

Work is underway to plan targeted vaccinations in affected areas, with two different vaccines for protection against the virus on offer in Australia, the Department of Agriculture, Water and the Environment said.

There is no risk of transmission from consuming pork, and the disease cannot be spread from human to human.