AUSTRALIA could be in for a bad flu season with most states already recording above average cases of the infectious respiratory disease.
NSW Health is reminding people with symptoms of flu to stay away from aged care facilities after a series of influenza outbreaks.
The Immunisation Coalition has reported more than 21,000 cases across Australia from January to the end of March compared with just over 10,000 for the same period last year.
Worst hit has been NSW with 6834 laboratory confirmed cases, Queensland 6606, SA 3317 and Victoria with 2655. WA has reported 1429, Tasmania 258 the ACT 183 and the Northern Territory 268.
Eight outbreaks at aged care facilities were reported in NSW in February.
NSW Health's Communicable Diseases Branch Director, Dr Vicky Sheppeard, said several factors were contributing to the high level of unseasonal flu cases.
"Some of the increase follows a late influenza season across tropical parts of Australia, which affected northern NSW, and now it's likely that travellers returning from the northern hemisphere are bringing flu home with them.
Influenza activity last winter was the lowest recorded since 2013.
Dr Sheppeard said it was concerning to see outbreaks at aged care facilities.
"Residents of aged care facilities will have little immunity left from last year's flu vaccine, so it's important to not expose them to the risk of influenza," Dr Sheppeard said.
"If you have a fever, cough or runny nose please postpone visiting elderly relatives until you recover.
"If you have symptoms of flu it's important to prevent the spread by coughing and sneezing into your elbow, washing your hands regularly, and staying home if you're unwell."
Vaccination is recommended between mid-April through to the end of May, to ensure the best protection during the flu season, which is normally from June to September, with a peak in August.
People 65 years and over, pregnant women, those who suffer chronic conditions and Aboriginal and Torres Strait Islander people from 6 months of age are eligible for free flu vaccinations, however doctors may charge a consultation fee.
An enhanced trivalent vaccine, Fluad(r) (Seqirus), is being supplied for those aged 65 years and over.
It can take two to three weeks for the effectiveness of a vaccine to reach its full potential.