Japanese encephalitis virus (JEV)
Japanese encephalitis virus (JEV) is a rare but potentially serious infection in humans that is transmitted by a bite from an infected mosquito.
Infection in humans is most commonly asymptomatic, however in less than 1% of infections, it can result in severe disease called encephalitis that requires hospitalisation and can result in serious long-term outcomes.
Find out more about JEV vaccination.
What you need to know in the ACT
In early 2022, JEV was detected for the first time in commercial pig farms and in humans in New South Wales, northern Victoria, South Australia and Queensland - indicating the virus is likely circulating in the mosquito population where it hasn’t been found before.
There have been no confirmed human cases of JE in the ACT at this time, however residents of Canberra and surrounding areas should take action to avoid mosquito bites.
We are monitoring the situation closely and will provide updates on the latest health advice on the public health alerts page and our social media channels:
Symptoms
Less than 1% of people infected with JEV will experience symptoms. If symptoms do develop, it is usually 5 to 15 days after a bite from an infected mosquito
Some infected people experience an illness with fever and headache.
People with severe infection (encephalitis) may experience neck stiffness, confusion, disorientation, tremors, coma or seizures.
If you experience these symptoms, you should seek urgent medical assistance.
How JEV is spread
Infection in humans occurs following a bite from an infected mosquito. Mosquitoes can become infected after biting an infected pig or waterbird. Mosquitoes cannot become infected after biting infected humans.
JEV cannot be passed from person to person.
Humans cannot become infected by eating meat from an infected animal.
Prevention
Actions to protect yourself against mosquito bites include:
- Covering up as much as possible with loose-fitting light-coloured clothing and covered footwear when outside.
- Using an effective insect repellent on exposed skin and reapply within a few hours. The best mosquito repellents contain Diethyl Toluamide (DEET), Picaridin, or oil of lemon eucalyptus.
- Using insecticide sprays, vapour dispensing units (indoors) and mosquito coils (outdoors) to clear rooms or repel mosquitoes from an area.
- Covering all windows, doors, vents and other entrances with insect screens.
- Removing any water-holding containers outside the house where mosquitoes could breed.
- Ensuring accommodation, including tents, are properly fitted with mosquito nettings or screens.
Find out more information on protecting yourself against mosquitos.
Diagnosis
JEV infection is usually diagnosed by measuring levels of antibodies to JEV in samples of blood or spinal fluid. If you have been infected, you do not put others at risk, as this disease cannot be passed from person to person.
If you have symptoms consistent with JEV please seek medical treatment.
Treatment
There is no specific treatment available for JEV. The best way to avoid infection is to avoid being bitten by mosquitoes.
JEV in animals
JEV in animals is a nationally notifiable disease.
For more information about protecting animals in your care, and what to do you if you suspect an animal is showing signs of the disease, go to the Environment, Planning and Sustainable Development Directorate website.
More information
JEV is a notifiable condition. For more information about JEV, contact your GP or call the Health Protection Service, Communicable Disease Control Information Line during business hours on 02 5124 9213.