Doctors have reported a spike in influenza cases across Australia, with 25,000 confirmed cases reported to state and territory health authorities to the end of September.
It is the highest number this decade apart from the swine flu epidemic two years ago.
Queensland is the worst-affected state with more than 10,000 cases, while New South Wales was next with half that number.
Per-capita infection rates have been highest in Queensland, South Australia and the Northern Territory.
Fifteen per cent of all flu cases reported nationally this year have been in children younger than four - the highest rate in any age group.
Queensland Health spokeswoman Dr Christine Selvey says her state’s large number of infections is a result of a rigorous testing regime.
"What we do know is that there’s always more influenza than is ever diagnosed, and so it’s really related to how much testing will determine how many notifications we get in many ways," she said.