It is, after dengue, the most widespread flavvirus in the world. Therefore, as other RNA viruses (Zika, yellow fever or dengue, infects mammals, whose man, by the bite of an infected mosquito. In mid-July, a first case of the western Nile virus (“Western Nilo” in English) appeared in the proposal-alpes-côte d’Sur region.
The western Nile virus, active between May and November, is mainly transported by birds: servants such as ducks and pigeons or wild, with particular migratory species, which transport the Africa virus to the temperate areas of Europe and Asia, where they were established in summer.
Common mosquitoes of the genus “Culex”, to differentiate themselves from the Tigre mosquito, are a kind of particularly vector diseases. They were infected by clicking on these birds that carry the virus, before transmitting it to humans, considered by the Pasteur Institute as “accidental hosts.”
What symptoms?
In its online file, the French Foundation indicates that, in the vast majority of cases (80%), “the infection of the western Nile virus is asymptomatic.”
However, in some rare cases, the western Nile virus can lead to a significant fever of three to six days after the bite, but is accompanied by “headache and back, muscle pain, cough, swelling of the neck nodes and, often, cutaneous eruption, nausea, abdominal pain, diarrhea and respiratory symptoms.”
To summarize, 20% of people chopped by an infected mosquito with the western Nile virus will suffer a pseudo-record syndrome. The Pasteur Institute indicates that neurological complications can be driven by an infection, in less than 1% of cases, especially in immunocompromised or elderly people.
In these cases, if the patient can generally recover alone, sometimes with consequences, “viral infection can be fatal mainly in older adults.”
39 Aboriginal cases in 2024
The Western Nile virus was first identified in the African continent, in Uganda, in 1937. In Europe as in France, the first cases in humans were recorded in the 1960s.
“Today, it is endemic in the Mediterranean perimeter, Central Europe and North America, where it is responsible for fatal human cases,” explains the Pasteur Institute.
“The first aboriginal case of Western Nile in 2025 was identified in France in France. The case is in the Provence-Alpes-Côte d’Azur region and presented the first symptoms on July 15,” said Public Health France in his last bulletin.
On the date, cases have been identified in three other European countries in July: in Greece, Italy and Romania. In 2024, 39 people had contracted the western Nile virus in France, mainly in the southeast of the country and 1,300 in Europe.
Source: BFM TV
