Sydney, Mar 9 (IANS): Australian state of New South Wales (NSW) confirmed its first death of Japanese encephalitis on Wednesday amid warning of a national spread of the virus.

The state Health department said the case was a man aged in 70s, who died in a Sydney hospital in February, Xinhua news agency reported.

The death was among the three known cases of Japanese encephalitis in NSW. The other two cases that were announced previously were a man and a child currently being treated in hospitals.

NSW Health said several more people in the state are still undergoing further testing for the virus, and more cases are expected to be confirmed over the coming days.

Japanese encephalitis virus is spread through the bite of an infected mosquito to people and animals. Most human infections of the virus cause no symptoms or mild symptoms such as headache or fever, while children aged below five years and senior citizens, who are infected are at a higher risk of developing more severe illness.

Health authorities in the neighboring state of Victoria also confirmed earlier this week that a resident in his 60s died of the virus in late February.

The Victorian health department urged anyone experiencing symptoms such as headache, vomiting, disorientation, seizures or coma, particularly if they've visited the Murray River area near the border of Victoria and NSW should seek urgent medical attention.

The federal Department of Health already declared the Japanese encephalitis virus a Communicable Disease Incident of National Significance last week after several cases were detected in multiple states.