RSV infection rates lowest in years

Despite the global outbreak of COVID-19 this year, many children may actually have been healthier than previous years with new research showing more than an 85% reduction in RSV and bronchiolitis presentations and admissions to Sydney Children’s Hospitals Network.

Respiratory syncytial virus (RSV) is a common respiratory virus and major cause of bronchiolitis. Bronchiolitis a chest infection that is a leading cause of hospitalisation in young kids and is normally prolific during autumn-winter months.

The research, led by Dr Philip Britton, Staff Specialist, Department of Infectious Diseases and Microbiology at The Children's Hospital Westmead and published in The Lancet Child and Adolescent Health showed that across Sydney Children’s Hospitals Network testing for RSV doubled this year compared with previous years but that infection rates still remained markedly lower.

Comparing frequencies in peak RSV epidemic months (April-June) in children 16 years and under for 2020 with those in 2015-2019, researchers found that the average frequency of RSV detected in pathology tests and a number of children admitted to hospital for bronchiolitis was 95% and 85% lower respectively than originally predicted for 2020, while ED presentations for acute respiratory illness were 70% lower.

They also found an 89% reduction in bronchiolitis admissions to the intensive care unit during this same period compared to the same timeframe in preceding years.

“We were keen to look into this because our doctors reported not seeing the usual levels of respiratory infection during the early pandemic. We wanted to know just how much of a reduction had occurred, and the reduction was startling. 

“We estimate that more than 300 hospital admissions and more than 40 ICU admissions were avoided,” Dr Britton said.

Aggressive public health interventions aimed at preventing SARS-CoV-2 (the virus responsible for COVID-19) transmission may have had something to do with the low infection rates.

“The hallmarks of the public response in NSW between February and May were enhanced hygiene, especially hand washing, and physical distancing. These were associated with a rapid drop in RSV rates when they would normally have been going up and down to levels none of us can recall for that time of year,” Dr Britton said.

While it remains to be seen whether community RSV transmission has been averted in 2020 or merely delayed as a result of the COVID-19 pandemic and its associated restrictions, researchers are encouraged by their findings and are hopeful increased awareness of hygiene measures will continue to help improve infection rates into the future.