Impact of COVID-19 Pandemic Interventions on Sudden Unexpected Death in Infancy Incidence in France.

OBJECTIVE

To study the impact of nonpharmaceutical interventions implemented during the COVID-19 pandemic on the monthly incidence of sudden unexpected death in infancy (SUDI) cases overall and those with a viral or bacterial identification.

STUDY DESIGN

We conducted an interrupted time-series analysis using seasonally adjusted Poisson regression models from the French national prospective and multicenter SUDI registry, that included all SUDI cases below the age of 1 year who died from 2016 to 2021 in mainland France.

RESULTS

Of 998 SUDI cases analyzed, 750 were recorded during the prepandemic period (January 2016 through March 2020) and 248 during the NPI period (April 2020 through December 2021). We found a significant seasonal pattern of overall monthly SUDI incidence, with a peak observed periodically from November to February. The monthly SUDI incidence decreased significantly from the prepandemic to NPI periods (adjusted incidence rate ratio 0.83 [95% CI 0.72-0.96]). In particular, the monthly incidence of SUDI cases with a viral or bacterial identification decreased significantly, while no significant difference was found for SUDI cases without a viral or bacterial identification.

CONCLUSIONS

Nonpharmaceutical interventions were associated with a significant change in the incidence of SUDI cases with a viral or bacterial identification. Further investigations are needed to analyze the pathophysiologic role of viruses and bacteria in the SUDI.