Western Australia has experienced historically low levels of respiratory syncytial virus (RSV) and influenza this winter due to the public health measures implemented to prevent the spread of COVID-19.

Researchers from the Wesfarmers Center of Vaccines and Infectious Diseases, based at Telethon Kids Institute, Perth Children's Hospital, and PathWest found a staggering 98.0% drop in RSV and a 99.4% reduction in influenza virus detections in WA kids.

Research published in Clinical Infectious Diseases found the closure of borders against international travelers from March onwards, as well as increased hygiene practices and social distancing, significantly reduced transmission of the key seasonal viruses that have a major impact on hospital admissions each winter.

Dr. Daniel Yeoh, Perth Children's Hospital pediatric infectious diseases specialist, said that even a return to school in term two—the perfect environment for spread of germs—hasn't driven case numbers up, which indicates that the lack of RSV and influenza establishment early in the season has prevented the usual community transmission.

"Our research shows that closing borders to travelers stopped these viruses from arriving in the State at the start of winter, preventing transmission and leading to unprecedented low levels of disease. It is possible that this pattern will be replicated in the northern hemisphere, where they are only just entering their winter season," Dr. Yeoh said.

"While this has been an unexpected benefit of the COVID-19 pandemic, border closures are unlikely to remain in place in the future so it will be interesting to see what happens next. Unfortunately, next winter may be more severe than usual, as immunity levels throughout the community will be low due to lack of exposure in 2020."

According to Dr. Hannah Moore, co-head of the Infectious Disease Epidemiology team at the Wesfarmers Center of Vaccines and Infectious Diseases, the COVID-19 pandemic has given researchers a rare opportunity to see how stay-at-home measures and increased focus on hygiene impacts the spread of other infectious diseases.

"We are now extending our study to look at emergency department visits and hospitalisations for a range of conditions in various age groups to further investigate the impact of the COVID-19 lockdown," Dr. Moore said.

"Data from the Eastern States suggests that hospital admissions due to respiratory viruses like croup and bronchiolitis have also reduced. Further research will help us learn potential ways to reduce the spread of infection when it is back circulating in the community and minimize the number of kids experiencing severe, life-threatening illnesses," Dr. Moore concluded.