Sydney researchers have found that lockdowns and travel restrictions have led to the emergence of geographically specific variants and off-season outbreaks of the childhood virus respiratory syncytial virus (RSV).
There were 1140 RSV cases in the week ending May 22, up from 766 the previous week and 508 the week before that, according to NSW Health.
RSV is the most common cause of respiratory and breathing infections in children and severe cases can result in lung infections such as bronchiolitis or pneumonia.
More than 900 children under the age of five presented to hospitals in May with bronchiolitis – around 40 per cent of these cases were then admitted.
Researchers from The University of Sydney’s Institute for Infectious Diseases found that lockdowns and travel restrictions had allowed geographically specific variants and off-season outbreaks of RSV to emerge.
“Restrictions put in place to limit the spread of SARS-CoV-2 were also very effective at limiting the spread of existing respiratory pathogens like influenza, RSV and rhinovirus,” lead researcher Dr John-Sebastian Eden told NCA NewsWire.
Now that restrictions have eased, people are more vulnerable to winter viruses.
The researchers noticed that a novel strain of RSV was being transmitted in Western Australia, where borders were closed for longer than other states.
Predictions that the virus would return with a force after the easing of lockdowns were proven correct, but it arrived far earlier than expected during the summer.
“It was completely unprecedented to see,” Dr Eden said.
After almost no cases during the first winter lockdown of the pandemic, outbreaks of the virus arrived over the following summer in higher rates than typically seen in winter.
Dr Eden said there had been a sharp rise in cases of RSV as well as the flu, rhinovirus and adenovirus in recent weeks.
“Influenza and RSV have the highest rates of hospitalisation and impact the most vulnerable in our community, so it is important we remain vigilant and do our best to avoid others if feeling unwell,” he said.
Victorian doctors reported an alarming rise in children presenting to emergency departments with RSV during late summer 2021.
Children and teenagers also account for more than half of flu cases in NSW so far this year.
There is no vaccine to protect against RSV, so health experts advise that the old faithfuls of hand washing, wearing masks and staying home when you’re sick are the best ways to reduce the spread of the virus.
Free flu shots will be available for free for all NSW residents throughout the month of June starting on Wednesday.