Key Points

• In 2025, 1,779 cases of acute hepatitis A were diagnosed in France.
• This was the highest number of cases since mandatory reporting began in 2006, excluding the 2017 outbreak, which primarily affected men who have sex with men (3,391 cases).
• A major outbreak (227 cases) occurred in Loire-Atlantique during the summer in the Nantes metropolitan area. A smaller outbreak was also observed in the Rhône region, with 93 cases occurring between July and September.
• An increase in the number of cases was also observed beginning in early 2025 in Mayotte following Cyclone Chido and Storm Dikeledi.