Carolina Williams is celebrating her 49th birthday and she has more than one reason to be happy.
Three weeks ago, the Toowoomba businesswoman feared she might not live to celebrate the occasion after coming down with the flu.
“I had lots of aches and pains and a fever. In the end due to my breathing problems, I had to call the ambulance,” Ms Williams said.
She was so sick doctors considered putting her in an induced coma.
“Initially it felt to me like a normal cold, the difference was, it escalated quite quickly,” she said.
Ms Williams is one of the nearly 217,000 Australians diagnosed with influenza so far this year.
The national death toll officially stands at 430, although the real figure could be much higher with experts saying some deaths are attributed to other causes despite flu-related complications.
In Queensland this year, at least 84 people have died.
Mother of three Jacinta Foulds died in hospital this month after being admitted when her flu symptoms worsened.
Her grieving husband pleaded with people to get vaccinated.
“I’ve got three kids without a mum because of a flu,” he said.
“This stuff kills.
“If you’re sick, go to the doctor.”
It is one of the worst seasons in two decades, second only to the flu epidemic of 2017.
In some states the flu season appears to be over, but the number of people being diagnosed in the eastern states remains high.
The very young and the elderly are the most at risk.
Margaret Power, 88, visited her local GP when she felt unwell.
“It wasn’t real serious, but I thought I’d get on top of it early,” she said.
But things quickly went from bad to worse with Ms Power spending the last few weeks recovering in hospital.
She had contracted the most common circulating strain, influenza A.
Krispin Hajkowicz treated Ms Power after she arrived by ambulance at the Royal Brisbane and Women’s Hospital.
“Margaret was very unwell when she came in and unfortunately developed a severe pneumonia and blood stream infection related to her flu.”
The Director of the Hospital’s Infectious Diseases Unit, Dr Hajkowicz said he’s never seen a flu season like it.
“We’ve all been working very hard, the hospitals have been dealing with very large number of cases of influenza through the emergency department, the general wards and the intensive care units.”
Normally, flu cases spike in the cooler months, between June and September.
This year, health authorities were caught by surprise when the season started much earlier than usual.
A report by the World Health Organisation Influenza Centre described the outbreak as “exceptional.”
Report author Professor Ian Barr said the number of cases was about “five times what we’d normally see in that inter-seasonal period”.
“2019 … may actually exceed the 2017 season,” he said.
Now the race is on to find out why.
Jianyun Lu, has travelled from China to study the unusual flu season under the tutelage of the University of Queensland’s, Kirsty Short.
They have discovered a slight association with climatic factors, but not enough to account for the large spike.
“We can’t explain 100 per cent why, when it’s over 25 degrees Celsius, why we have a very sharp increase,” Dr Lu said.
So they have turned their attention to the virus itself.
There was an unusual number of children hospitalised with flu over summer and it’s the strains isolated from those patients that the researchers have under the microscope.
Dr Short said they are investigating whether certain mutations were enabling the virus to “survive longer in the environment”, or allowing it to “transmit better”.
“By the end of the year, I think we’ll have a good understanding of potential factors that could have contributed to our unusual summer flu,” Dr Short said.
Professor Barr identified a large outbreak in the Northern Territory at the end of last year, and a mild-2018 influenza season as contributing factors and said there needed to be year-round surveillance.
“In Australia we rely on a number of different reporting mechanisms, so we can track influenza seasons. Some of these are run all year round, but a number of them, such as the surveillance in hospitals, only run from April to November,” he said.
“We need to be better prepared. Maybe we can tweak the vaccination timings if we see these early outbreaks.”
A record 12.5 million vaccines have been distributed so far this year.
Vaccination didn’t help Carolina Williams and Margaret Power but Dr Hajkowicz said it was still “the best way to protect yourself and those who might not be able to have the strongest immune response to their own vaccination.”