Victorians warned about risk of mosquito-borne disease

Health authorities are warning visitors to the Murray River to be extra vigilant about the risk of a potentially deadly bite this weekend.

Health experts are warning everyone planning to spend time along the Murray River this Easter to be extra vigilant about mosquitoes.

New research published in the Australian and New Zealand Journal of Public Health shows that mosquito-borne virus Japanese encephalitis can infect numerous people in areas where mosquitoes are carrying the disease.

Victorian Deputy Chief Health Officer Associate Professor Deborah Friedman, who also co-authored the research paper, said the community needed to be aware that the mosquito-borne illness posed a severe health threat.

“We investigated whether there was evidence of JE infection among populations exposed to the disease for the first time. It is a rare but grave health concern,” she said.

She said it was a “timely reminder” that mosquito-borne diseases were circulating.

“Testing in Northern Victoria shows that approximately 3 per cent of people in affected areas where mosquitoes carry the disease have been infected – a much larger proportion of people than the number of reported cases of illness.”

Of those infected, it is estimated that every one in hundred people will develop an illness, including a severe brain infection.

The mortality is typically 20 – 30 per cent, while 30 – 50 per cent of cases develop long-term neurological disability following infection.

According to the Victorian Department of Health Campaspe, Gannawarra, Greater Shepparton, Indigo, Loddon, Mildura, Moira, Swan Hill, Wodonga, Towong, Benalla, Wangaratta, Strathbogie, Buloke, Greater Bendigo, Hindmarsh, Horsham, Northern Grampians, West Wimmera and Yarriambiack are at greatest risk.

The community is encouraged to protect themselves from mosquitoes with repellent and wear light-coloured and loose clothing.

“If you live in or are travelling to affected regions this Easter avoid being outside at peak mosquito times, including dawn and dusk and dispose of any stagnant water where mosquitoes can breed,” Prof Friedman said.

Experts believe Australians are mainly vulnerable to Japanese encephalitis because they typically have not had prior exposure to the virus.

Before 2022, the disease was found in the Torres Strait, Papua New Guinea and Asia, with only a small number of cases acquired in far north Queensland in the 1990s.

However, locally acquired disease cases were reported in South-Eastern Australia and Northern Victoria, including Corowa, last year.

Public Health Association of Australia chief executive, Professor Terry Slevin, said the public needed to be well prepared to tackle new and emerging public health threats.

“There is little doubt that the migration of Japanese encephalitis into South-Eastern Australia is linked to climate change, and we expect to see more of these climate-related public health issues in the future,” she said.

Prof Slevin said the research revealed the challenges when responding to a disease where we have limited relevant experience available to determine the best course of action.

“Australia learnt a lot from our experience of COVID-19, and the Albanese Government promised during its election campaign to establish an Australia Centre for Disease Control to tackle exactly this sort of emerging threat,” she said.

“JE isn’t just an issue in Victoria – there have been cases in other states. As a hopefully well-resourced central body, the Australian Centre for Disease Control could coordinate the cross-border response to these public health incidents – including collating evidence, conducting surveillance, and leading public education and vaccination availability and roll-out.”