Agriculture officials have revealed their theory for how the Japanese encephalitis virus came to NSW.
“It's speculated from a couple of sources; possibly water birds have migrated down to follow the water given there are larger areas of water here now, in our part of the world,” NSW Agriculture Minister Dugald Saunders told a budget estimates hearing on Tuesday.
He added another possibility was mosquitoes carrying the virus had travelled by wind all the way down south.
Mr Saunders said he had been in regular conversations with the Health Minister and Regional Health Minister about the outbreak.
“It’s a human issue and mosquito-borne disease,” he said.
“Thankfully we have amazing biosecurity which has actually helped pick up the movement through piggeries, and that’s actually helping inform where the concern is.”
Six people have so far been confirmed infected in NSW.
The mosquito-borne virus, which had never been observed in the state before this year, is commonly transmitted to the insects from infected pigs.
It has previously mostly been detected in southeast Asia.
Most infected people will feel no symptoms but in rare cases the virus can cause headaches, convulsions and unconsciousness.
Vaccines can protect against the virus but once a person is infected there is no specific treatment.
People in affected areas have been urged to avoid getting bitten by xjmtzywmosquitoes.
The sixth person to be infected in the state lives in the Balranald area in the Riverina region and is receiving treatment in a Victorian hospital.
The man in his 60s was confirmed infected on Monday.
