Key Points 

Imported Cases 

• 11 cases of chikungunya
• 24 cases of dengue
• 2 cases of Zika  

Locally acquired cases

• One locally acquired case of West Nile virus infection was identified in the city of Perpignan (66) in the Pyrénées-Orientales department. The individual had presented with suggestive clinical signs on July 7. This is the first detection of the virus circulating in humans in France in 2026. Standard prevention and management measures have been implemented in response to this transmission, notably to ensure the safety of blood donations and organ transplants.
• An autochthonous case of dengue fever was identified in the town of Sète in the Hérault department (34). The individual had exhibited symptoms suggestive of dengue fever on July 5. The index case was identified and had recently returned from India.
  Standard prevention measures (vector control, awareness-raising among healthcare professionals, press release, and ensuring the safety of blood donations and transplants) have been implemented. A door-to-door survey was conducted on July 22, 2026. The area remains under active surveillance.
• An autochthonous case of dengue fever in the Tarn department has been identified in the town of Carmaux (81). The individual had presented with symptoms suggestive of dengue on June 19 but was confirmed on July 17 following a delayed report on July 15. This is the first detection of dengue virus circulation in this department in 2026. The usual preventive measures (LAV, awareness-raising among healthcare professionals, press release, safeguarding blood and transplant donations) have been implemented.
• An autochthonous case of chikungunya was identified in the town of Saint-Amans-Soult in the Tarn department (81). The individual had presented symptoms suggestive of chikungunya on July 9, and the diagnosis was confirmed on July 22. A door-to-door investigation was conducted on July 28, 2026. This is the first detection of chikungunya virus circulation in this department in 2026. The usual preventive measures (handwashing, raising awareness among healthcare professionals, and ensuring the safety of blood and organ donations) have been implemented.