NSW Health is alerting the community to protect themselves against mosquito bites.

Japanese encephalitis virus has been detected in samples from commercial pig farms at five locations in southern and western NSW indicating the virus is likely circulating in the mosquito population.

JE is a mosquito borne disease that may affect animals, including pigs, and humans. The virus is spread by mosquito bites.

"It is really important to protect yourself from mosquito bites as mosquitoes can spread viruses including Japanese encephalitis," said Dr Kerry Chant, Chief Health Officer.

Less than 1% of people infected with JE experience symptoms, which typically include fever, joint pain, and rash. Occasionally, JE can cause severe a neurological illness with headache, convulsions and reduced consciousness.

"There is no specific treatment for JE or other mosquito-borne viruses. The best way to avoid infection is to avoid being bitten by mosquitoes", Dr Chant said.

Simple actions to avoid mosquito bites include:

• Cover up as much as possible with light-coloured, loose-fitting clothing and covered footwear when outside.
• Use 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.
• Use insecticide sprays, vapour dispensing units (indoors) and mosquito coils (outdoors) to clear rooms or repel mosquitoes from an area.
• Cover all windows, doors, vents and other entrances with insect screens.
• Remove any water-holding containers outside the house where mosquitoes could breed.

View further information on mosquito-borne disease and ways to protect yourself.

Fact sheets on specific mosquito-borne diseases, including Japanese encephalitis Ross River virus and Barmah Forest virus, are available on Vector borne disease fact sheets.