Initially, David and Natalie Robertson were told their 10-week-old twins had a mild infection.
Their three-year-old son, Leon, had caught a common virus known as respiratory syncytial virus (RSV) at daycare three weeks ago and shared the illness with babies Hugo and Margot.
Last year, their two-year-old daughter Olive had the potentially harmful virus, so they knew to monitor the newborns closely.
When Margot's blood oxygen reading became worrying low, they took the pair to emergency.
"We knew from previous years that it's pretty serious," said Mr Robertson.
Soon after arriving at hospital, it was clear Hugo's condition was worse than his sister's.
His rapid breathing showed he was struggling to get air.
He needed to be seen by specialists at Westmead Children's Hospital.
So for three days, the twins and their parents were split between two hospitals.
The Robertsons said both paediatric wards were full of children with RSV.
Hospital admissions for children rising
According to the NSW Respiratory Surveillance Report, the week the twins were in hospital, 721 children aged 0-4 years were taken to an emergency department for bronchiolitis, which in infants is usually associated with RSV.
Of these, 42 per cent were admitted to hospital.
Dr Philip Britton, an infectious diseases paediatrician at Sydney Children's Hospitals Network, said he expects it will be a long, difficult winter.
Not only have RSV infections shot up, but so have cases of several types of influenza.
Dr Britton said RSV mainly affects children aged under one and influenza mostly affects those between one and five years old.
But he said this year, they were seeing more school-aged children with flu than usual.
Respiratory infections make a comeback
RSV and other respiratory viruses are striking in other states as well.
Western Australia reported 1,024 cases of RSV in people of all ages in the first half of 2022, while Queensland recorded more than 300.
Tasmanian authorities didn't have specific data on RSV but said the state was seeing an increase in flu-like illness this winter.
"We expect to see ongoing increases in respiratory viruses, including COVID-19, influenza, RSV and others, in the coming weeks," a Tasmanian Department of Health spokesperson said.
According to Dr Michael Bonning, president of the New South Wales Australian Medical Association, the pandemic is to blame for our vulnerability.
In 2020 and 2021, influenza cases dropped significantly as measures to stop the spread of COVID-19 also interrupted the transmission of the flu virus.
Dr Bonning said that meant people had not built up immunity through exposure.
"We are really relying on people's immunity derived from vaccination more than anything else because they haven't had exposure in the last two years," he said.
He said many people had not kept their vaccines up-to-date, making the population ripe for an influenza outbreak.
"There are many, many immune-naive people who it can spread to," he said.
Usually influenza infections spike, then die down, but Dr Bonning said he expected this flu season to continue for several months.
That will mean many more people, including young children, being hospitalised, he said.
Healthcare pushed to the brink
Dr Britton said people accepted respiratory illness in winter as normal, but they should instead do whatever they could to stop these diseases spreading.
That includes not ignoring mild symptoms in adults.
The increased need for care comes at a time when Australia's hospital system is already stretched due to high levels of influenza and COVID19 in the community and in healthcare staff.
Mr Robertson said Mount Druitt Hospital in Sydney's west, where he and his wife first took the twins, was at its limit.
"Their emergency department was full, the wards downstairs were full," he said.
He noticed the same at Westmead Children's Hospital.
"When I got into emergency — that was midnight on Saturday — it was full," he said.
"There were kids, just so many kids, sitting at the front all coughing."
Dr Bonning said he was worried about the healthcare system's ability to cope.
"Our hospital system is already dealing with record levels of demand," he said.
He said anything the public could do to limit the spread of disease, would take pressure off the healthcare system.
Dr Britton agreed.
"Any help we can get from the community in terms of reducing the amount of infection, reducing the severity infection is critical," he said.
"We're asking you now to help us, particularly for the coming three or four months."
Back to basic public health measures
The help they're asking for is nothing new — it's everything Australians have been doing to stop the spread of COVID-19 over the past few years: hand hygiene, cough and sneeze etiquette, masking up, staying home if unwell and getting vaccinations.
Professor Kristine Macartney, director of the National Centre for Immunisation Research and Surveillance and a paediatric infectious disease specialist, said Australia's vaccine coverage this year was not good enough.
She said previously almost 50 per cent of Australian children were vaccinated against flu, but this year the rate was only just over 20 per cent.
Most states are currently offering free flu vaccines to all residents.
"It's not too late for your child to get vaccinated against flu. We still have many months of winter to get through," Professor Macartney said.
She said staying at home when you are sick or keeping sick children at home was particularly important for limiting the spread of RSV, because there is no vaccine against that virus yet.
Mr Robertson would also like more precautions to keep RSV out of day care centres.
He said parents had to test children for COVID-19 and were notified if that virus was detected, but for young children, RSV was also a significant risk.
"I think they need to test for RSV and the numbers need to be reported the same way COVID was," he said.
