Rates of sudden unexpected infant death (SUID) and sudden infant death syndrome (SIDS) saw an increase during the COVID-19 pandemic compared to the immediate period before the pandemic, as highlighted in a recent study. The notable rise in SUID cases was linked to a resurgence of seasonal respiratory viruses, especially RSV (respiratory syncytial virus), implying that changes in SUID rates might be tied to different patterns in the transmission of infectious diseases.
A recent study from researchers at the Penn State College of Medicine reveals that the incidence of sudden unexpected infant death (SUID) and sudden infant death syndrome (SIDS) spiked during the COVID-19 pandemic, especially in 2021, compared to the pre-pandemic era. The monthly reports of SUID in 2021 paralleled a resurgence of seasonal respiratory viruses, most notably respiratory syncytial virus (RSV), indicating a potential relationship between SUID rate changes and infection transmission dynamics.
The study’s results were published today (Sept. 26) in JAMA Network Open.
“SUID is thought to stem from multiple factors. Despite efforts to educate about safe sleep practices and initiatives encouraging parents to put infants to sleep on their backs, SUID rates remain high,” stated Emma Guare, a fourth-year medical student at Penn State College of Medicine and the lead author of the study. “We hypothesized a possible connection between infections and SUID and aimed to understand this relationship better, particularly as infection rates shifted during the pandemic.”
According to the Centers for Disease Control and Prevention (CDC), around 3,700 infants faced unexpected deaths in the United States in 2022. SUID encompasses unexpected fatalities of infants under one year old due to both known and unknown reasons. SIDS is a specific type of SUID occurring during sleep, where the cause remains unknown even after thorough investigations, representing about one-third of SUID cases.
The research team analyzed the rates of both SUID and SIDS during the COVID-19 pandemic and contrasted them with data from the immediate pre-pandemic period. From March 1, 2018, to December 31, 2021, national mortality data from the CDC recorded 14,308 SUID cases.
Upon comparison, the team found an uptick in SUID and SIDS during the pandemic when looking at monthly occurrences compared to the pre-pandemic time. The largest jump occurred in 2021, with SUID and SIDS rates increasing by 9% and 10%, respectively, compared to the previous period. A significant rise in SUID rates was noted from June to December 2021, showing a monthly increase of between 10% and 14% relative to pre-pandemic figures.
Initiatives implemented to curb the pandemic effectively limited the spread of respiratory infections, including RSV, keeping their prevalence low throughout 2020. However, as these restrictions were eased in the pandemic’s second year, seasonal respiratory viruses began circulating more broadly and intensely at unexpected times.
While there were minimal RSV-related hospitalizations in 2020, cases surged from June to December 2021 during an atypical RSV season, as it is generally active from October to April. This seasonal shift in RSV closely aligned with the monthly fluctuations in SUID observed in 2021.
“We are still unclear about the specific reasons making certain infants more susceptible to SUID or SIDS, whether it relates to genetics or other factors. Infections like RSV might exacerbate these vulnerabilities,” remarked co-author Erich Batra, an associate professor of pediatrics and family and community medicine at Penn State College of Medicine. “Particularly concerning RSV, there have been discussions about whether it leads to increased apnea (temporary cessation of breathing) compared to other viruses and if that might create conditions favorable for SUID.”
The team emphasized that more research is necessary to fully comprehend the role of infections in SUID and SIDS and whether infections such as RSV could be contributors to some SUID and SIDS incidents.
“Maintaining safe sleep practices is crucial, particularly when infants are unwell,” Batra advised. He urged caregivers to continue placing babies on their backs to sleep, avoiding soft bedding, and refraining from bed-sharing.
Other contributors from Penn State College of Medicine involved in the study include Catharine Paules, associate professor of medicine; Vernon Chinchilli, Distinguished Professor of Public Health Sciences; Paddy Ssentongo, assistant professor of public health sciences; and Rong Zhao, a doctoral student in biostatistics.
