A new study today in JAMA Network Open shows that pediatric hospitalizations for respiratory syncytial virus (RSV) doubled during the 2022-2023 season compared to the prior year.
The population-based cohort study of children aged 5 years and younger in Ontario, Canada, looked at hospitalization and intensive care unit (ICU) admissions for RSV from July 1, 2017, through March 31, 2023.
On average, 700,000 children per study year were included. Though the 2021-2022 season peaked a bit earlier than prepandemic seasons, the number of hospitalizations was similar, at 289.1 per 100,000 children in 2021-2022, compared to 281.4 to 334.6 per 100,000 in 2017 through 2020.
In 2022-2023, however, RSV season peaked a month earlier and resulted in more than twice as many hospitalizations (770.0 per 100 000).
ICU admissions tripled
The RSV hospitalizations also led to more ICU admissions.
”The proportion of children admitted to an ICU in 2022-2023 (13.9%) was slightly higher than prepandemic (9.6%-11.4%); however, the population-based rate was triple the prepandemic levels (106.9 vs 27.6-36.6 per 100 000 children in Ontario)," the authors said.
The rate of mechanical ventilation use was also two- to three-fold higher in 2022-2023 compared with prepandemic years, the authors said.
During 2020 and 2021, cases of RSV dropped as COVID-19 mitigation measures, including masking and school closures, halted transmission of RSV. In Ontario, only 11 RSV hospitalizations and seven ICU admissions occurred during the 2020-2021 season. But in 2022-2023, a resurgence was seen as RSV, flu, and COVID-19 all co-circulated with most mitigation efforts removed.
The unexpected and widespread influences on seasonal respiratory viruses that followed the COVID-19 pandemic underscore the need for ongoing research.
"The unexpected and widespread influences on seasonal respiratory viruses that followed the COVID-19 pandemic underscore the need for ongoing research to understand the impact of pandemic mitigation measures and the unique factors of transmission for common pathogens to ensure societies are better prepared to respond to future pandemics," the authors concluded.