Africa: Growing Concern As Mosquito-Borne West Nile Virus Gains Ground in France
[RFI] France's national health agency has recorded more than 161 cases of West Nile virus and five deaths since its annual seasonal surveillance began on 1 May. Transmitted to humans by mosquitos, which contract it from birds, the virus is progressing rapidly across Europe. Experts say global warming is fostering the spread of such tropical diseases.
Since May, France's national health agency has reported over 161 cases of the West Nile virus and five deaths from the mosquito-borne disease. Transmitted to humans through infected mosquitoes, which contract it from birds, the virus is rapidly spreading across Europe. Global warming is believed to be contributing to the spread of such tropical diseases.
As of October 7, the French public health agency, Santé Publique France, recorded 161 human cases of the West Nile virus nationwide. Of these, 28 were asymptomatic and detected during routine blood donation screening, while 133 were symptomatic. Among those with symptoms, 60 cases were neuro-invasive, resulting in five deaths. The agency warns that the deaths may not be directly attributable to the virus.
The first recorded cases in France appeared in the 1960s, primarily in the Mediterranean basin and the Camargue. The virus has since spread to several other French regions, including Île-de-France, which includes Paris. In 80% of cases, the disease remains asymptomatic, while in 20%, symptoms resemble flu, including fever and headaches. Rarely, the virus can cause encephalitis and meningitis, leading to fatal outcomes.
There is no commercially available vaccine or preventive treatment for the virus. Yannick Simonin, a virology professor at the University of Montpellier, cautions that the reported figures likely represent only a fraction of the actual cases. Humans are considered dead-end hosts, as they do not develop high levels of the virus and cannot transmit it to mosquitoes.
The West Nile virus is primarily transmitted by the Culex pipiens mosquito, which has always been present in Europe. Mosquitoes become infected from birds, either migratory or locally infected. As of September 30, the national agency for horse veterinarians recorded 364 symptomatic cases in horses and 18 cases in birds across eight regions of France. Birds are asymptomatic carriers but can infect mosquitoes, which then bite humans and horses, making them accidental hosts.
The virus is currently circulating quite vigorously across Europe, with just under 80 deaths reported. Global warming is contributing to the spread of the virus, with warmer temperatures shortening the mosquito's development cycle, leading to larger populations. Climate change also affects bird populations and migration routes, potentially influencing virus transmission patterns.
Written by urgent.news from AllAfrica Health's reporting — not their text. Machine-written — may contain errors; check the original before relying on it.
