A multidisciplinary and structured investigation of three suspected clusters of transverse upper limb reduction defects in France.

INTRODUCTION: Between 2019-2021, facing public concern, a scientific expert committee (SEC) reanalysed suspected clusters of transverse upper limb reduction defects (TULRD) in three administrative areas in France, where initial investigations had not identified any risk exposure. We share here the national approach we developed for managing suspicious clusters of the same group of congenital anomalies occurring in several areas. METHODS: The SEC analysed the medical records of TURLD suspected cases and performed spatiotemporal analyses on confirmed cases. If the cluster was statistically significant and included at least three cases, the SEC reviewed exposures obtained from questionnaires, environmental databases, and a survey among farmers living near to cases' homes concerning their plant product use. RESULTS: After case re-ascertainment, no statistically significant cluster was observed in the first administrative areas. In the second area, a cluster of four children born in two nearby towns over two years was confirmed, but as with the initial investigations, no exposure to a known risk factor explaining the number of cases in excess was identified. In the third area, a cluster including just two cases born the same year in the same town was confirmed. DISCUSSION: Our experience highlights that in the event of suspicious clusters occurring in different areas of a country, a coordinated and standardised approach should be preferred.

Investigation of a cluster of acute epiglottitis in Vendée, western France, October - December 2022.

OBJECTIVES: In our investigation of an episode of clustered acute epiglottitis occurring in Vendée, western France, between October and December 2022, we described the reported cases and confirmed its unusual character at several geographic levels. METHODS: The investigation relied on three data sources: hospitalization and emergency department reports; national reference centre data; and data from the French syndromic surveillance system. RESULTS: The six patients were male, with an average age of 42 years [32-66]; all were hospitalized in an ICU, and one of them died. Documented risk factors for epiglottitis (active smoking, regular alcohol consumption, overweight) were present in the majority of cases. No causal pathogen was identified. Syndromic surveillance data confirmed increased acute epiglottitis at the local, regional and national levels. CONCLUSION: We not only characterized the episode of serious clustered acute epiglottitis in Vendée, but also observed a nationwide increase in this pathology occurring concomitantly with increased circulation in France of streptococcus A.

Nirsevimab Effectiveness Against Cases of Respiratory Syncytial Virus Bronchiolitis Hospitalised in Paediatric Intensive Care Units in France, September 2023-January 2024.

In September 2023, France was one of the first countries that started a national immunisation campaign with nirsevimab, a new monoclonal antibody against respiratory syncytial virus (RSV). Using data from a network of paediatric intensive care units (PICUs), we aimed to estimate nirsevimab effectiveness against severe cases of RSV bronchiolitis in France. We conducted a case-control study based on the test-negative design and included 288 infants reported by 20 PICUs. We estimated nirsevimab effectiveness at 75.9% (48.5-88.7) in the main analysis and 80.6% (61.6-90.3) and 80.4% (61.7-89.9) in two sensitivity analyses. These real-world estimates confirmed the efficacy observed in clinical studies.