As of December 1, 2023, 43 locally acquired human cases of West Nile virus infection (contracted in mainland France) have been identified in three regions.

In Nouvelle-Aquitaine, 33 cases were identified: 26 cases in Gironde, 5 cases in Charente-Maritime, and 2 cases in Charente. Symptoms began between the second half of July and the end of September. Animal infections were also identified as part of the animal component of surveillance for this virus: equine cases were reported in Gironde and Charente-Maritime, as well as avian cases in Charente-Maritime. All these cases indicate ongoing circulation of the West Nile virus in Gironde, Charente-Maritime, and Charente. This marks the first identification of human cases of West Nile virus infection outside the Mediterranean region. The identification of equine cases in 2022 had already shown that the virus was present in Gironde.

In Provence-Alpes-Côte d’Azur, 8 human cases have been identified: 3 cases in Alpes-Maritimes, 3 cases in Bouches-du-Rhône, and 2 cases in Var. The onset of symptoms in these human cases occurred between mid-July and late August. Equine cases have also been identified in the Bouches-du-Rhône.

• See the epidemiological update

In Corsica - 2 human cases were reported in Haute-Corse in late August. Equine cases have also been identified in Corsica.

• See the epidemiological update

For more information:

• Weekly International Health Surveillance Bulletin
• European surveillance (ECDC)

As of January 9, 2023, six human cases of West Nile virus infection in France—including three neuroinvasive forms—contracted in France have been reported:

• 2 cases in the Bouches-du-Rhône department near Aix-en-Provence, with symptoms beginning in late August and late September;

• 3 cases in the Var department in two neighboring towns near Toulon, with symptoms beginning in mid-August and during the second half of September;

• A fourth human case, with symptoms that appeared late, during the second week of December 2022, was identified in the Var. This is a neuroinvasive form; the diagnosis was confirmed by the CNR for arboviruses.

These human cases occurred while:

• 4 equine cases were also identified in the Var in August and September;

• Two equine cases were identified in Haute-Corse in October and November;

• 3 equine cases were confirmed in Gironde in October; this marks the first identification of West Nile virus outside the Mediterranean region.

• In 2021, there were no human cases and 3 equine cases, including 2 in Haute-Corse and 1 in the Var.

• In 2020, there were no human cases and 5 equine cases, including 3 in Southern Corsica, 1 in Upper Corsica, and 1 in the Var.

• In 2019, 2 human cases, including 1 neuroinvasive form, were reported in the Var. There were also 13 confirmed equine cases, including 9 in the Bouches-du-Rhône, 2 in the Gard, and 2 in Haute-Corse.

• In 2018, a resurgence of the West Nile virus was observed, with 27 cases of autochthonous human infection—including 7 neuroinvasive forms—along the French Mediterranean coast, primarily in the Alpes-Maritimes. There were also 13 confirmed equine cases, including 1 in Bouches-du-Rhône, 7 in Gard, and 5 in Haute-Corse.

• In 2017, two human cases (febrile, non-neuroinvasive forms) were identified in the Alpes-Maritimes, as well as an asymptomatic infection in a horse.

• In 2015, one human case (febrile, non-neuroinvasive form) was identified in the Gard, while a major equine epizootic was raging, with 48 infected horses, mainly in the greater Camargue region (Gard, Hérault, and Bouches-du-Rhône).