Health authorities in Australia are warning of a possible outbreak of Murray Valley encephalitis, a potentially deadly virus transmitted by mosquitos.
It has recently been found in so-called sentinel chickens, kept in at-risk areas in New South Wales as an early warning system for health officials.
Humans can also be infected.
The BBC reports that while many patients show only mild symptoms, some may suffer long-term neurological problems as a result of brain infections or even die.
Health officials are warning people living, or visiting, near rivers and wetlands to protect themselves against mosquitos.
The last outbreak of Murray Valley encephalitis was in the 1970s.
It is most commonly found in remote northwestern parts of Australia but can surface in the southeast after heavy rain and hot weather.