Introduction – In late 2023, the Nouvelle-Aquitaine region experienced a surge in outbreaks of foodborne illness linked to the consumption of oysters, primarily during the holiday season. The study aimed to assess the public health impact of this outbreak and to identify risk factors, such as the circulation of noroviruses and heavy rainfall, which are known to impair the quality of shellfish-farming waters.Method – Surveillance data on acute gastroenteritis (AGE) (emergency department visits, SOS Médecins calls, mandatory reports of foodborne illness outbreaks, and purchases of targeted medications by prescription) were analyzed in conjunction with rainfall records.Results – A sharp increase in various AGE indicators among those aged 15 and older was observed, with an exceptional peak in week 52 of 2023: 469 emergency department visits, three times more than in 2022. Precipitation in November 2023 was 2.5 times higher than normal, coinciding with an increase in cases of GEA among children.Discussion-Conclusion – Every winter, the holiday season contributes to a resurgence of GEA, but the 2023–2024 outbreak in Nouvelle-Aquitaine was particularly severe among those aged 15 and older. This outbreak may be linked to norovirus contamination of shellfish farms. The combination of viral gastroenteritis circulating among children and heavy rainfall leading up to the holidays may have contributed to this outbreak, resulting in a surge in cases of food poisoning. Although these GEA outbreaks appear to be mild, they have a significant impact on the healthcare system, underscoring the importance of reporting any suspected foodborne illness to enable a rapid response from health authorities.