NSW has recorded its first probable human case of Japanese encephalitis virus (JEV).
The person is a resident in the NSW-Victoria border region and is in a stable condition in intensive care.
Several more people in NSW are undergoing further testing and more cases of the virus, which is spread by mosquitoes, are expected to be confirmed in coming weeks.
The virus has been declared an issue of national significance and NSW Health is warning the public to be vigilant and safeguard themselves against mosquito bites, as there is no specific treatment for JEV.
Earlier today Queensland recorded its first human case of JEV — a woman in her 60s who is in a critical condition on life support after a camping trip in the south of the state.
Her diagnosis follows the recent detection of Japanese encephalitis in animal samples taken from a Goondiwindi commercial piggery in the state's south.
JEV can cause severe neurological illness, with headache, convulsions and reduced consciousness in some cases.
The virus can infect animals as well as humans, and was recently confirmed in samples from a number of pig farms in NSW, Queensland, South Australia and Victoria.
Locally acquired cases of JEV have never previously been identified in NSW in animals or humans, as JEV is usually only found in far northern Australia and neighbouring countries.
Mosquito-control activities are being carried out in the vicinity of farms where pigs are confirmed to have been infected by JEV, and NSW Health is arranging vaccinations for workers on affected farms.
The virus cannot be transmitted between humans, and it cannot be caught by eating pork or pig products.
NSW's Acting Chief Health Officer Marianne Gale said the best way to avoid infection was to avoid being bitten by mosquitoes, which are most active between dusk and dawn.
"NSW Health is cautioning people undertaking outdoor activities such as camping and fishing to carefully consider their plans," Dr Gale said.
"This is especially important for people planning activities near waterways or where mosquitoes are present, particularly the Murray River and its branches.
"People should be particularly vigilant given the recent wet weather conditions, which have led to very high mosquito numbers that may increase further in the coming days and weeks."
NSW Health is working closely with the NSW Department of Primary Industries and other state and territory agencies to determine the extent to which the virus is circulating, through animal testing and mosquito monitoring.
Health authorities recommend these simple actions for avoiding mosquito bites:
- Wear long sleeves and pants outdoors and wear shoes and socks where possible. There are insecticides (eg permethrin) available for treating clothing for those spending extended periods outdoors
- Apply repellent to all areas of exposed skin: the most effective are those containing DEET, picaridin or oil of lemon eucalyptus. The strength of a repellent determines the duration of protection, with the higher concentrations providing longer periods of protection
- Reapply repellent after swimming. The duration of protection from repellent is also reduced with perspiration, such as during strenuous activity or hot weather
- Apply sunscreen first and then apply repellent
- Mosquito coils and other devices that release insecticides can assist in reducing mosquito bites but should be used in combination with topical insect repellents
- Reduce all water-holding containers around the home where mosquitoes could breed. Mosquitoes only need a small amount of liquid to breed