An off-season spike in respiratory syncytial virus may have contributed to a rise in sudden unexpected infant deaths during the pandemic, according to a new study from researchers at Philadelphia-based Penn Medicine.
Researchers used national mortality data from the CDC to compare monthly rates of SUID before and during the pandemic. From 2019 to 2021, SUID rates per 100,000 live births increased, with the largest rise in 2021. That year, SUID and sudden infant death syndrome or SIDS, a type of SUID, rose by 9% and 10%, respectively.
"There was a notable shift in SUID rates from June to December 2021, when the monthly rate of SUID increased between 10% and 14% compared to pre-pandemic levels," researchers said in a news release.
The increase correlated with an off-season surge in RSV, suggesting the infection may be associated with SUID rates. The research team emphasized that additional research is needed to better understand the role of infection in sudden infant deaths.
"We don't know what makes babies who die from SUID or SIDS more vulnerable, whether it’s genetics or something else," Erich Batra, MD, study author and an associate professor of pediatrics and family and community medicine at Penn State College of Medicine, said in the release. "It could be that infections like RSV amplify those factors and make them more vulnerable. With RSV in particular, there have been questions about whether RSV causes more apnea, when you stop breathing temporarily, than other viruses and if that contributes to an environment conducive to SUID."
About 3,700 infants died in the U.S. from SUID in 2022, according to CDC data.
The full study was published Sept. 26 in JAMA Network Open and can be found in full here.