Key Points

• Between the start of mandatory reporting in August 2023 and December 2025, 139 cases of leptospirosis were reported in Auvergne-Rhône-Alpes.
• In 2024, the reporting rate in the region (0.9 per 100,000 inhabitants) was higher than the average rate observed in mainland France and Corsica.
• Cases were reported in all departments of the region, with the highest rates observed in Savoie in 2024 and 2025.
• Case characteristics were similar to the national pattern, with a marked predominance of males, a median age between 40 and 50 years in 2024 and 2025, and a seasonal pattern with more cases in summer and early fall.
• Severe forms of the disease are common, with over 80% of cases requiring hospitalization, a third of which required intensive care.
• The main reported risk exposures were contact with animals, the presence of rodents, and swimming activities.