Key Points

Exposure to Ticks

• About 6% of people living in Auvergne-Rhône-Alpes report having been bitten by a tick during the year;
• The use of preventive measures has increased slightly compared to 2019.

Lyme disease

• Transmitted by Ixodes ricinus ticks, this is the most common tick-borne disease in the region, with an estimated 4,600 cases and 96 hospitalizations in 2024;
• Overall decline in case incidence in primary care and hospitals since 2019.

Tick-borne encephalitis

• Two known modes of virus transmission: through tick bites (the most common) or through food (raw milk or raw-milk cheeses);
• 27 cases reported in 2024 in Auvergne-Rhône-Alpes: on the rise since the start of surveillance through mandatory reporting in 2021;
• Haute-Savoie, a historical hotspot for the disease, accounts for half of the region’s cases;
• Livestock farmers are particularly at risk.

Hyalomma marginatum tick

• Recent establishment of the Hyalomma marginatum tick in Drôme-Ardèche associated with the emerging risk of Crimean-Congo hemorrhagic fever.