Influenza-related Deaths in Young Children: Observations From a German Case Series

BACKGROUND: Seasonal influenza virus infections remain a major public health burden. During the last years, several case reports of severe influenza infections in children have been published. CASES: We report 4 fatal influenza cases in young children (2-6 years old) which occurred in Southwest Germany in the seasons 2022/23 and 2023/24. All 4 children were previously healthy; a forensic autopsy was conducted due to an unknown cause of death. Postmortem samples from the respiratory tract and organ tissues were tested for respiratory viruses via real-time polymerase chain reaction (RT-PCR) and analyzed by whole-genome sequencing. RESULTS: In 1 child, RT-PCR revealed influenza B virus, and 3 children died with influenza A (H1N1)pdm09 infection. No mutations associated with high virulence were detected. In 1 case, influenza A(H1N1)pdm09 could be cultivated in cell culture from brain tissue. CONCLUSIONS: This case series underlines the potential risk of fatal outcomes of influenza infections in children. This should be considered when re-evaluating the vaccination recommendations for healthy children.