A woman in her 60s who travelled to the Griffith region was diagnosed with the infection, NSW Health said.

She was treated in hospital and recently discharged and is continuing to recover at home.

It is the second confirmed case of Japanese encephalitis from northwest NSW's Riverina region, after a Griffith man became the second person in Australia to die after contracting the infection.

The man in his 70s died in a Sydney hospital on February 13, and results of his autopsy showed he had contracted Japanese encephalitis before his death.

A Victorian man in his 60s died with the infection on February 28.

There have now been 16 human cases of the virus in Australia, including seven in Victoria, one in Queensland and four in NSW.

Several other people are undergoing testing for the illness and NSW Health expects further cases to be confirmed.

The virus is spread by mosquitoes and can infect humans and animals, but cannot be passed from person to person, NSW Health said.

It also cannot be caught by eating pork products.

Since February this year, the illness has been detected in samples from pig farms in NSW, Queensland, Victoria and South Australia.

"There is no specific treatment for JE, which can cause severe neurological illness with headache, convulsions and reduced consciousness in some cases," NSW Health said in a statement.

The best thing to do is try to prevent yourself and your family from being bitten by mosquitoes.

NSW Health recommends:

* Avoid the outdoors, bushland and wetlands at peak mosquito times - dawn and dusk

* Wear long sleeves and pants, socks and shoes

* Use insecticides (e.g. permethrin)

* Use and reapply repellent (e.g. DEET, picaridin, or oil of lemon eucalyptus)

* Use mosquito nets for children, and mosquito coils

* Empty and reduce all water-holding containers around your house.

Australian Associated Press