[LUM#2] Should we be afraid of the tiger mosquito?
Chikungunya and dengue outbreaks in France—really? While global warming does indeed bring health risks, such a threat isn’t currently a concern in our part of the world.
It may have been your most faithful companion this summer, with its familiar buzzing and its appetite for bites. Its nickname sends a shiver down your spine: the tiger mosquito, Aedes albopictus to those in the know. Having arrived in the south of France about ten years ago, it has now expanded its territory all the way to the capital. Is global warming to blame?“Certainly notsolely,” replies Jean-François Guégan of the Infectious Diseases and Vectors Laboratory : Ecology, Genetics, Evolution, and Control.
“The arrival of the tiger mosquito in France has nothing to do with the climate,”the researcher asserts. The cause, he explains, is“the global increase in maritime and air traffic, which has enabled it to reach Europe.” In particular, the trade in used tires—a prime breeding ground forAedes albopictus larvae.“Without the role of transportation, the tiger mosquito could not have spread from Lyon to Paris in a single year,” the specialist emphasizes. He does not entirely rule out climate change:“It is undeniable, however, that the insect can establish itself in regions made more suitable by rising temperatures,” explains Jean-François Guégan.
No worst-case scenario in sight
Problem: Adult tiger mosquitoes can carry certain viruses, including those responsible for dengue and chikungunya. Should the few recent cases of these diseases in the south of France be cause for alarm?“The presence of the tiger mosquito does not necessarily mean an outbreak of dengue or chikungunya. For that to happen, the life cycle of these viruses would need to become established here,” reassures Jean-François Guégan. This requires conditions favorable to the mosquito’s development, the virus’s development, and its transmission to humans.
While global warming is a contributing factor, it is not the only determining factor.“Prevention policies, the economic situation of the countries involved, changes to natural habitats, and the vulnerability and exposure of individuals and populations are all factors that come into play,” explains Jean-François Guégan. The tiger mosquito will likely continue to add a bit of a sting to your summer evenings, but cases of dengue and chikungunya should remain isolated or be quickly contained. Phew, that was a close call.
Shellfish and crustaceans
Far less noticeable than cases of dengue and chikungunya, an increase in cases of gastroenteritis and infections has been observed in recent summers in the Vendée, Charente-Maritime, and Gironde regions. The culprit: Vibrio vulnificus. “A bacterium that proliferates due to rising coastal water temperatures, ”explains Jean-François Guégan. It concentrates in shellfish and can thus be transmitted to humans.“A direct consequence of global warming on human health,” the researcher emphasizes.
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