General practitioner Natalie Caristo works on the frontline of the yearly influenza outbreak.
She says 2017 has been a bad year for the number of cases seen so far at the Abbotsford Medical Practice in Sydney's inner west, where she works.
"There's definitely been a significant increase in the number of cases of the flu recently. This year's been quite severe, and, particularly, we've been seeing both Influenza A and Influenza B spiking at the same time. And the type of illness that we've been seeing has been quite severe, particularly hitting the more vulnerable members of the population."
The rush of flu-infected patients at Dr Caristo's practice is part of a widespread surge in cases.
New South Wales Health Pathology's senior medical virologist, Professor Bill Rawlinson, says the potentially unprecedented spike began four weeks ago.
"They've come up very quickly. So we haven't had many cases, then, about mid-July, all of a sudden, we saw a really big uptick in the number of cases. We're still midway through. We're really at the peak of flu at the moment. And what we would normally see is, over the next two to three weeks, falling numbers but continuing flu. At the moment, it does appear that the rise has been higher than in previous years."
Over the past 10 years, the number of lab-confirmed flu cases has gone through peaks and troughs.
From little over 10,000 in 2007, it climbed to more than 90,000 last year.
The highest number of cases in a year so far was in 2015, with more than 100,000 recorded.
So far this year, just over 75,000 infections have been confirmed, easily above the numbers at the same stage that year.
The Royal Australian College of General Practitioners' Dr Bastian Seidel says the lab-confirmed cases are just a small part of the story.
"Every year, we are seeing 300,000 Australians who do contract the flu. Eighteen thousand of them are going to be admitted to hospital because of complications, and, unfortunately, 3,000 Australians will die from complications of influenza."
Professor Rawlinson, the virologist, says, while no-one is immune from contracting the flu, some people are more likely to have a serious reaction.
"People with diabetes, people with chronic heart or lung disease, people who've received transplants, Aboriginal and Torres Strait Islanders who are, particularly, over the age of 50, as well as elderly people -- and they're defined as over 65 -- those groups are really at risk of more severe illness."
Dr Seidel, from the Royal Australian College of General Practitioners, says the focus should be on prevention.
He suggests the government should make influenza vaccinations free for every Australian.
"You're asking me whether we should be spending money to prevent influenza in the first place? Absolutely. It would be key to vaccinate everyone from the age of six months onwards, not only the ones who are at risk, because everybody is going to be at risk. You know, influenza doesn't ask any questions. It can affect everybody."
Dr Seidel also has a message for the public: It is never too late to be vaccinated.
