Two Cases of Autochthonous West Nile Virus Encephalitis, Paris, France, 2025.

Summary: Two people in France recently got very sick with brain swelling caused by the West Nile virus. What makes this surprising is that one person never left Paris, and the other only traveled within France. Usually, this virus is found in warmer climates or caught during foreign travel. Because these two cases happened just days apart, doctors are worried that the virus might be spreading locally to new areas in France.