Hepatitis A is a notifiable disease (presence of anti-HAV IgM in serum) that must be reported immediately by any appropriate means to the ARS physician. In France, this surveillance system was established in 2005, and more recently in Mayotte in 2009. Due to the risk of spread, the potentially greater severity in adults, and the existence of public health control measures, hepatitis A must be subject to departmental surveillance, the objectives of which are to detect cases in order to implement appropriate control measures, estimate incidence and trends, and describe risk factors and their evolution.In 2011, in mainland France, the annual incidence rate of reported cases was 1.6 per 100,000 inhabitants. Of these, 35% were part of a cluster of cases that underwent in-depth investigations. In 2011, the French overseas departments accounted for less than 11% of the total number of cases recorded in metropolitan France, with more than 70% of these cases occurring in Mayotte.