The government has urged livestock owners to be vigilant for signs of this infectious disease as routine surveillance indicated the virus is still present in parts of the New South Wales region.
State and Western NSW Agriculture Minister Dugald Saunders said mosquito numbers are expected to increase in the coming weeks, given prolonged periods of wet weather across the state.
“As we recover from heavy rains and head toward warmer temperatures, conditions are ideal for Japanese encephalitis to spread,” he said.
Japanese encephalitis is caused by the Japanese encephalitis virus (JEV). It is transmitted through mosquito bites and is more common in areas of increased mosquito activity.
Saunders said the disease will not pose a food safety risk, but could cause reproductive failure in pigs, with losses of 50 to 70 percent reported in previously affected populations.
“We are encouraging ranchers to be on high alert for sick cattle, with clinical signs of infection including high fever, jaundice, lethargy, anorexia and neurological signs including lack of coordination and vision problems,” he added.
Japanese encephalitis infections in humans are usually asymptomatic, but rarely can cause severe illness and even death.
NSW Health Minister Brad Hazzard also warned residents who frequently live or work in areas identified with the disease to take precautions, such as vaccinations and wearing long-sleeved clothing to avoid mosquito bites.
The state provides free JEV vaccines to people 2 months and older who usually live or work in areas of high concern for JEV or at increased risk of exposure to mosquitoes.
Since it was first detected in Australia in 1995, Australian-acquired human cases of JEV have been very rare, but by 2022, the number has increased, with human cases identified in several states. As of October 19 this year, 42 cases of JEV infections have been reported in Australia since January 1, 2021. ■