Japanese encephalitis (JE) is a serious disease caused by the Japanese encephalitis virus (JEV). It is spread to humans by infected mosquitoes. Humans are not able to pass JEV to other humans.
NSW Health is monitoring the evolving situation in NSW concerning Japanese Encephalitis virus. This page will be updated weekly with the latest information on confirmed cases.
*Confirmatory testing for JE is complex and takes time, therefore day of confirmation may be well after onset of illness.
Confirmed cases have potentially been exposed in these Local Government Areas:
NSW Health undertakes mosquito surveillance across NSW from November to April each year. In response to Japanese Encephalitis (JE) outbreak, NSW Heath has expanded the mosquito surveillance network around the infected piggeries and to areas where human cases have been reported. The mosquito samples (including samples collected prior to JE outbreak) are being tested for Japanese Encephalitis virus (JEV). Positive results are documented in the table below.
*Recent samples have tested negative for JEV
NSW Health undertakes sentinel chicken surveillance in inland areas of NSW from December to April each year. The blood samples collected from the chicken flocks during the surveillance season are being tested for Japanese Encephalitis virus (JEV). Positive results are documented in the table below.
The NSW Arbovirus Surveillance and Mosquito Monitoring Program is closing the season for 2021-22, with the week ending 14 May 2022 being the final week. The start date of the 2022-23 season will be dependent on climatic conditions in Spring. Weekly reports from the current season and past seasons can be found at
Surveillance - Vector-borne diseases.
JE is spread by the bite of infected Culex species mosquitoes which are commonly found in NSW.
The virus is spread when mosquitoes bite an infected animal and the mosquito then bites a human. Infected pigs and some waterbirds are the animals more likely to infect mosquitoes.
Humans cannot get infected with JEV by touching an infected animal or eating animal products including pork or poultry products.
JEV has recently been identified in commercial piggeries in locations in NSW, Queensland, Victoria and South Australia. Local infection risks in NSW are likely highest among:
The best way to avoid JEV is to avoid mosquito bites.
The mosquitoes that transmit JEV are most active at dawn and dusk and into the evening.
A safe and effective vaccine for JE is available for people aged 2 months and older.
Less than 1% of people infected with JEV will experience symptoms.
Some infected people experience an illness with fever and headache.
People with severe infection may experience:
If you have any of these symptoms please seek medical treatment.