A total of 198 influenza A and B cases were recorded last month, compared to 50 in June 2016.

It’s a similar story across the state, with 2781 cases in June this year, compared to 1196 last year.

HNEH population health physician Dr David Durrheim said the data was “just the small tip of the iceberg”, as it only accounted for samples sent to labs for testing by doctors.

“The flu season has definitely arrived,” Dr Durrheim said.

“We had an early seasonal spike, but it went away – in the last three weeks we’ve seen it come back with a large increase in cases.”

In most of Australia, the peak flu season usually runs from August to September.

Dr Durrheim said while more flu cases were always expected in winter, the dramatic June increase was in part due to an “opening up of the gap between those people who are vaccinated and those who are unvaccinated”.

“The flu vaccine in health adults is about 70 per cent effective in reducing the risk of influenza, depending on how well it is matched with that particular strain,” Dr Durrheim said.

“This really the last opportunity for people to make sure they get jabbed with the vaccine. We don’t know how big this flu season will be, so this is a good warning.”

If it’s too late for you, and you’ve caught the dreaded bug or feel it coming on, Dr Durrheim said staying at home was the most important thing.

“Stay in a stable and warm environment, drink lots of fluids and take something to keep your fever down,” he said.