For the first time, indigenous cases of “West Nile” fever, transmitted by mosquitoes, were observed in Île-de-France, the health authorities announced on Wednesday, while chikungunya households multiply in mainland France.
“Two indigenous cases of infection by the Western Nile virus-West Nile Virus-were detected in people residing in Seine-Saint-Denis”, summarizes the Regional Health Agency of Île-de-France in a press release. “These are the first identifications of local vector transmission of the West Nile virus in Île-de-France.”
This virus is transmitted via mosquito bites. But, unlike chikungunya or dengue, it is not the tiger mosquito that is involved, but the genus Culex, much more widespread in metropolitan France.
Another difference with these two other diseases, “West Nile” fever is not transmitted from one human to another by the mosquito, but from an infected bird.
The infection is generally without symptoms, but in about a fifth of the cases it gives rise to a flu. In less than 1% of cases, serious complications may appear, sometimes causing death.
Aboriginal cases – that is to say resulting from on -site contamination – have already been reported in metropolitan France in previous years – forty in 2024 – but never so in the north.
This summer, apart from the two Ile-de-France cases, five other indigenous cases were recorded in the south, in Provence-Alpes-Côte-d’Azur, said the National Public Health Agency France in another report, published on Wednesday.
Public Health France also continues to follow the evolution of Aboriginal cases of Chikungunya in mainland France each week. They are this summer at a particularly high level this summer, after an epidemic in Reunion which facilitated the importation of the virus.
From now on, “23 episodes of Chikungunya totaling 115 cases (with) 1 to 23 cases per episode” were recorded in metropolitan France, according to Public Santé France, adding that six of these episodes are enclosed. The previous week, the results were 16 households for 63 cases, an already record level.
In terms of dengue, six households have been identified for a total of eleven cases. The previous week, the record rose to five homes for nine cases.
The transmission of dengue and chikungunya in mainland France is a consequence of the establishment of the tiger mosquito. He was still absent from the metropolis a few decades ago, but he now settled there, against a background of global warming.
