Between the appearance of the tiger mosquito in France and the resurgence on the planet of diseases transmitted by these insects, such as chikungunya or the Zika virus, mosquitoes are currently the focus of all scientific and media attention. “Diseases are not new, but their current geographic expansion is unprecedented, particularly due to the speed of transport, explains Pr Éric Caumes, infectious disease specialist and president of the Committee for Travel-Related Diseases and Imported Diseases. When it took several days by boat to go from one place to another, arriving at your destination, your body had ample time to eliminate the virus. Whereas now, when you get off the plane a few hours later on the other side of the world, the virus is still present in your blood. You get bitten by a mosquito, and that’s it: the transmission cycle is gone. »
Mosquitoes, vectors of disease
Mosquitoes are indeed disease vectors: it is by biting a healthy person after having bitten a sick person that the mosquito (exclusively the female) deposits the virus or parasite responsible in its blood. And these insects are perfectly able to adapt to new environmental conditions.
“The tiger mosquito, for example, is originally an insect from tropical areas, but it has adapted to our climate. Its eggs have the ability to go dormant during the winter to hatch in the spring. This genetic faculty allows it to survive in the temperate environment, which was not its original environment. specifies Fabrice Chandre, entomologist and director of the National Center of Expertise on Vectors.
Chikungunya, dengue fever, Zika virus… are diseases transmitted by the tiger mosquito (Aedes albopictus), native to the tropical forests of Southeast Asia, and now present in some 30 departments of metropolitan France, from Var to Bas-Rhin via the Vendée. Corn “It seems that this species transmits less efficiently than its cousin Aedes aegypti. In mainland France, we have not observed more than ten grouped cases of chikungunya or dengue fever. We are obviously not facing a high epidemic potential”, reassures Professor Caumes.
Our Experts
Pr Eric Caumes, infectiologist and chairman of the Committee for Travel-Related and Imported Diseases
Fabrice Chandre, entomologist and director of the National Vector Expertise Center
For further
Everything you need to know about the Zika virus
Good anti-mosquito strategies
