Key Points

• In Guadeloupe, in 2024–2025, the seasonal epidemic lasted 19 weeks; it began in late December (2024-52) and peaked in late January (2025-04) [Table 1]. The final week of the epidemic occurred in early May (2025-18), with indicators returning to baseline levels the following week. This epidemic was particularly long compared to previous years. Its impact was significant in outpatient settings but especially in hospitals, with a total of 20,360 outpatient visits and 1,264 emergency department visits for influenza or influenza-like illness (of which 11.4% were followed by hospitalization). The impact on hospitals was greater during this season than in previous seasons. A total of 19 severe cases admitted to intensive care units were reported, including 2 deaths attributable to influenza.

• In Martinique, as in Guadeloupe, the epidemic lasted 19 weeks and occurred from late December to late April (from S2024-51 to S2025-17) with an epidemic peak in S04-2025 [Table 1]. The impact of this epidemic was greater than in previous seasons. In fact, 20,150 patients consulted a general practitioner, and 1,697 SOS Médecins home visits were conducted during this period. Regarding hospital indicators, 410 people visited the emergency room for flu-like symptoms (of which 24.8% of visits were followed by hospitalization). In total, 10 reported severe cases were admitted to intensive care. No flu-related deaths occurred during this epidemic season. It should be noted that in Martinique, co-circulation of type A/(H3N2) and A/(H1N1)pdm09 viruses was identified during the 2024–2025 season, with a predominance of the type A/(H3N2) virus, unlike in the 2023–2024 season. In Guadeloupe, a predominance of the A-type virus was also observed this year. Regarding the B-type virus, it accounted for 30% of positive tests in Martinique and 21% in Guadeloupe.

• In Saint Martin, the epidemic lasted 18 weeks [Table 1]. It was longer than in previous years. Unlike in Martinique, Guadeloupe, and Saint Barthélemy, the epidemic began in early January (S2025-01) and ended in late April (S2025-17), with a peak in early January (S2025-02). Nearly 1,410 clinically suspected influenza cases and 53 emergency department visits (5.7% of which resulted in hospitalization) were recorded during this epidemic.

• In Saint-Barthélemy, the epidemic was shorter than in the other three territories, beginning in late December (S2024-52) and ending in mid-March (S2025-11) for a total of 12 weeks [Table 1]. The epidemic peaked in early January (S2025-02). With 318 clinically suggestive cases, 43 emergency room visits, and 4 hospitalizations, the 2024–2025 epidemic was more widespread than in previous seasons.