Nathan Brown, 19, is currently on life support in a medically-induced coma, after his organs began to shut down three weeks ago.

“He has fallen victim to this terrible influenza A virus as well as acute pneumonia and he has a staph infection in both lungs and in his heart,” his uncle Peter Brown wrote on a GoFundMe page set up to help pay for Nathan’s medical bills.

“His lungs have collapsed and his kidneys have stopped working. He is an extremely sick young man. It is going to be a very long and tough recovery for Natto once he beats this illness,” Mr Brown wrote.

“He will not be able to work for many months and his rehabilitation and ongoing medical expenses will be substantial. No kid deserves what he is going through and what lies ahead.”

Queensland 12-year-old Caleb Logan was also struck by this terrible flu and “double pneumonia” at the beginning of winter. He spent six weeks in hospital recovering.

“We were told ... that Caleb was very sick ... and that we had to prepare ourselves that he may die,” his father Darren Logan wrote on a GoFundMe page set up to pay for his medical costs.

“Caleb was diagnosed with influenza B & a secondary bacterial infection of staph aureus which was causing his high temps,” Mr Logan wrote.

“Caleb also contracted two stomach infections. Caleb had a blood transfusion and an operation procedure to put a drain in his chest cavity to drain fluid. If it wasn't for our perseverance Caleb would not be with us today.”

Health experts say this is Australia’s worst flu outbreak thanks to a particularly nasty strain,

Influenza A (H3N2).

More than 137,500 cases of flu have been reported so far this year including a record breaking 30,000 cases in August.

That’s more than double the 53,159 cases confirmed by this time last year and more than the total 83,092 cases confirmed by the end of the flu season in 2016.

“I’m confident this is not just the biggest on record but the largest flu outbreak we’ve seen for some time,” Immunisation Coalition chairman Professor Paul Van Buynder said.

Canberra mother-of-two Jennifer Thew died on the weekend from acute respiratory distress syndrome after contracting the flu.

Ms Thew, who worked as a medical receptionist in Canberra, had been vaccinated against the flu.

It is understood her seven-year-old daughter had also been unwell with the virus.

Rosie Andersen, 8, died last week just days after falling ill with the flu.

Rosie’s father Christian Brealey said she had been sick for a few days, but the family just believed she was suffering from a bad cold.

“Never in my worst dreams did I think it would end up like this,” he said in a statement.

He broke the news of Rosie’s sudden death by telling friends to “raise a glass guys”.

“I lost my beautiful princess today to influenza ... Went into cardiac arrest this morning around 9.30, by 12.00 she was gone and told there was nothing they could do. Can’t believe we lost her to something like the flu.”