The Latest Breaking News from Murray Valley

A Victorian man is reportedly in a critical condition in hospital after contracting Japanese encephalitis from a mosquito bite.

Health officials say there have now been four cases, inlcuding two fatal, of the disease this year in the Northern Territory compared to two cases in the previous five years.

A second woman has died and a man is in hospital in Victoria after contracting Murray Valley encephalitis, the deadly mosquito-borne virus.

A New South Wales man is in hospital after becoming infected with the first transmission of Murray Valley encephalitis in the state since 2011.

A woman from north west Victoria who died earlier this month was the first person to contract Murray Valley encephalitis in the state almost five decades.

Victorian health authorities have warned communities in the state's north-west to take precautions against mosquito bites as tests confirm a woman in her 60s who died earlier this month had the virus.

NT Health officials have issued a health alert after a person died with the potentially deadly Murray Valley encephalitis.

Authorities are urging people to apply insect repellent and wear long-sleeved shirts if venturing near mosquito-prone areas, after a fatal case of the brain infection was diagnosed in the Top End.

Health authorities warn there is a "very high" risk of human cases of Murray Valley encephalitis in coming weeks, as detections rise in the northern Victorian city of Mildura.