Image caption Cases of Murray Valley encephalitis have already been found in chickens

Health authorities in Australia are warning of a possible outbreak of Murray Valley encephalitis, a rare but potentially deadly disease.

The mosquito-borne disease has recently been found in chickens in Australia's most populous state, New South Wales. Humans can also be infected.

While many patients show only mild symptoms, some may suffer long-term neurological problems or even die.

The last outbreak of Murray Valley encephalitis was in the 1970s.

Neurological problems

The virus is mostly found in remote parts of Australia's north-west.

It is, though, occasionally seen in more heavily populated parts of the southeast after heavy rainfall and hot weather, conditions that favour the breeding of mosquitos, which transmit the disease.

The latest infection was detected in birds placed in hotspots for Murray Valley encephalitis, as part of an early warning system to detect the virus.

Health officials have warned the public to take precautions against mosquitoes, and to be aware of the symptoms of the disease, which can include severe headache, fever, neck stiffness, drowsiness and confusion.

People who have visited or live near wetlands or rivers are most at risk.