An “active circulation of West Nile and Usutu viruses in Gironde, Charente-Maritime, Haute-Vienne and Landes” noted this Wednesday by Santé Publique France, in its latest regional epidemiological report, carried out with ARS Nouvelle-Aquitaine.
The first indigenous human cases in New Aquitaine of Nile (or West Nile) virus infection were reported at the end of July. As of September 26, “twenty confirmed/probable indigenous human cases have been identified (onset of symptoms between mid-July and the end of August): 17 in Gironde and three in Charente-Maritime. Investigations are underway in six other people. » For the Usutu virus, at the beginning of August, two human cases of infection had been identified in the region, “as of September 26, six indigenous human cases, including four residents in Gironde, one in Landes and one in Charente-Maritime were identified” continues Santé Publique France.
98 anti-mosquito treatments in the region
From May 1 to September 22, 89 imported dengue cases and four imported chikungunya cases were identified in the region (compared to 30 imported dengue cases and three imported chikungunya cases from May 1 to November 30, 2022). “To limit the appearance of indigenous chains of transmission, 143 entomological surveys (search for mosquitoes) and 98 vector control treatments were carried out around cases residing or passing through the region. »
West Nile virus infection is a disease transmitted by mosquitoes of the genus Culex, active from June to the end of November, which become contaminated by feeding on infected birds. These mosquitoes are endemic in France. If the majority of cases (around 80%) are asymptomatic or minimally symptomatic, 20% of infected people present a flu-like syndrome (fever, joint and muscle pain, asthenia, headache) sometimes accompanied by a rash.
Usutu, a virus close to West Nile
Usutu virus infection is a pathology also transmitted by mosquitoes of the genus Culex. This virus is close to the West Nile virus and birds also constitute its main reservoir. Cases are most often asymptomatic or minimally symptomatic.
Chikungunya, dengue and Zika are notifiable diseases transmitted by mosquitoes of the genus Aedes, active from May to November. During this period, mosquito control interventions are carried out around the places frequented by the cases in order to limit the risk of transmission and the appearance of indigenous cases. All the departments of Nouvelle-Aquitaine are colonized by mosquitoes of the genus Aedeswith the exception of Creuse.