18 March, 2022

Japanese Encephalitis

As we have been hearing through the media, there have been sporadic cases of Japanese encephalitis in recent weeks through Vic SA and NSW, with 2 deaths recorded so far.


Japanese encephalitis virus (JEV) is a rare but potentially serious infection of the brain caused by a virus spread to humans through mosquito bites.

In the last week JEV has been detected in pigs in Victoria, New South Wales and Queensland.

Most JEV infections are asymptomatic, however those with severe infection (less than one per cent) may experience headache, vomiting, disorientation, seizures, coma, and more rarely, permanent neurological complications or death. The incubation period is 6-16 days. Children aged under 5 years old and older people who are infected with JEV are at a higher risk of developing more severe illness, such as encephalitis.

Several cases of encephalitis of uncertain cause were initially identified in New South Wales, near the Victorian border, and in South Australia within the past month. There are now several additional cases within Victoria. All cases had extensive mosquito exposure prior to illness onset and were in the areas near the Murray River. Their presentation and results so far are suggestive of JEV infection.

JEV has been confirmed in pigs at several piggeries in New South Wales, as well as three piggeries in Northern Victoria and in Goondiwindi, Queensland. JEV has however NOT BEEN DETECTED in mosquitoes in Victoria nor in other states at this point in time.


Avoid mosquito bites by using mosquito repellent containing DEET on all exposed skin.

Wear long, loose fitting clothing when outside.

Limit outdoor activity if lots of mosquitoes are about.

Use flywire screens

Mosquito coils can be effective in small outdoor areas where you gather to sit or eat.

The greatest risk are those living or working in rural environments between Mildura and Wodonga, and particularly those working in contact with pigs.

The risk of acquiring JE living in Melbourne’s urban environment is VERY LOW.

However, anyone experiencing these symptoms, particularly if they’ve visited the Murray River area between Mildura and Wodonga near the border of Victoria and New South Wales or been in contact with pigs, should seek urgent medical attention.


Those at greatest risk, eg working in contact with pigs or living in the rural communities affected, are recommended to be vaccinated.