The highly contagious virus potentially linked childhood asthma cases

Health experts are concerned that surging cases of respiratory syncytial virus in children will create a new wave of asthma sufferers in Australia, with infections in the first half of 2024 nearing the number for all of last year.

While the virus, known as RSV, can cause short-term symptoms such as a runny nose, cough, wheezing, breathing difficulties and fever, it has also been strongly linked to the onset of asthma in children who would otherwise not develop the chronic condition.

Cat Irvine believes multiple RSV infections led to her son Parker developing asthma.Credit: Stefan Gosatti

Asthma Australia medical adviser and respiratory physician Professor John Blakey said the highly contagious virus was estimated to be responsible for the development of up to 22 per cent of asthma cases in children under five. The infection is also linked to up to 27 per cent of asthma cases in children aged between five and 11.

“We know that viral infections interfere directly with the lining of the air tubes,” Blakey said.

“They also alter the way that the immune response works and tilt it towards that allergy-type response rather than a healing-type response.”

More than 104,000 RSV cases have been recorded in Australia so far this year, with case numbers on track to eclipse last year’s total of 128,110 cases.

Blakey said using vaccination to reduce the number of children becoming seriously ill with RSV would significantly curb the prevalence of asthma.

Australia has one of the highest rates of asthma in the world, with about 11 per cent of the population, or 2.8 million people, living with the chronic health condition.

About 80 per cent of children become infected with RSV before their second birthday, and it is the leading cause of lower respiratory tract infections, including bronchiolitis, an asthma-like chest infection.

In rare cases, children require hospitalisation.

Parker Irvine, 5, has been hospitalised with RSV three times and now suffers from asthma. He was first hospitalised with bronchiolitis caused by the virus when he was six weeks old.

Cat Irvine and her son Parker during his first hospitalisation for RSV when he was six weeks old.

His mother, Cat, took him to the emergency department after noticing he was struggling to breathe. The skin between his ribs and under his neck was pulling in with each breath – a sign that he needed urgent medical attention. The newborn was put on oxygen and feeding support in hospital.

“It is disappointing,” Cat said. “He could have been a well, healthy child, but because he has had RSV so many times, which has led to bronchiolitis, he now has asthma.”

Parker’s asthma flares up in cold weather and when he has a respiratory virus. He carries a puffer with him at all times, which he uses when he starts wheezing or coughing.

Parker Irvine, aged 2½ during his fourth admission to hospital for RSV.

Cat is a student midwife and has helped administer free RSV vaccines to newborns at her Perth maternity hospital. While the Western Australian and Queensland governments are funding the vaccine for all newborns, the NSW government is funding the jab for at-risk babies such as those born prematurely. There is no funded RSV vaccination program for children in Victoria.

“I am so pleased that it is available now, ” Cat said. “I think about what a difference it could have made to Parker.”

While numerous studies have established a strong correlation between falling ill with RSV at a young age and a child developing asthma, causation has yet to be proved.

It is hoped the rollout of free RSV vaccines in Western Australia and Queensland will provide researchers with the data to determine whether avoiding a serious RSV infection in infancy reduces the risk of developing asthma.

Associate Professor Rhys Allan, of the Walter and Eliza Hall Institute of Medical Research, said asthma was a complex disease that was caused by genetic and environmental factors.

These environmental factors might include viruses that cause lower respiratory tract infections and exposure to environmental allergens such as pollens, he said.

“If you get severe RSV in the early years of your life, and it leads to bronchiolitis, then that’s often linked to subsequent asthma when you get older,” he said.

“They can only still conclude that there’s just a really high correlation ... ultimately vaccination is going to be the key to understanding that.”

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