“The Spread of Aedes Albopictus, the Tiger Mosquito: A Public Health Crisis in Occitania Due to Climate Change and Globalization”

Some 5.5 million inhabitants are affected by Aedes albopictus. The “tiger” has now colonized all of Occitania. And global warming allows it to conquer mountainous territories. The ARS calls for the “mobilization of all” to limit the risks, including transmission of dengue fever, zika or chikungunya.

On Labor Day, the tiger mosquito takes off. It is, in any case, the date marked each year by the health authorities for “strengthen health surveillance” – until the end of November – linked to the presence of this insect which is “a public health problem capable of transmitting a large number of serious tropical diseases”, recalls Didier Jaffre. The director of ARS Occitanie (Regional Health Agency) puts it bluntly: “We will have to live with…”

“The tiger mosquito is implanted everywhere in all the thirteen departments of the Occitanie region”

The tiger mosquito – it is very small (less than a penny), with a really striped abdomen, which bites early in the morning or late in the evening, within a radius of 150 meters maximum because it flies evil – is now “established everywhere in all the thirteen departments of the Occitanie region”.

He prefers places where the population is large and dense cities, Montpellier and Toulouse in the lead.. But it is also found in sparsely populated or frequented places: we have flushed it out with certainty in 44% of the municipalities in the region, i.e. 90% of the population (5.5 million inhabitants). In short, this “serial killer”, as Eric Orsenna calls him, is formidable in adaptation. He is a champion, as we explained in Dis-Leur HERE in the curse of a star of globalization!

Present up to 1,500 meters of altitude…

And sometimes even where you thought it wouldn’t go: up to 1,500 meters in altitude and in the mountains, especially in the Hautes-Pyrénées where, in Adrest, last August, a single specimen (!) wreaked havoc by committing two autochthonous cases of dengue in Adrest and Rabastens-de-Bigorre. Autochthonous means that the affected person did not contract the disease during a trip but by being bitten by a mosquito in his usual environment which had previously bitten a carrier of this disease. Like the symptomsballots” resemble those of the flu – fever, pain, sometimes rash – it is obviously essential that the attending physicians are vigilant and request an examination in case of doubt.

Global warming, an accelerator

Global warming acts as an accelerator: the tiger mosquito colonizes new lands each year and its life cycle is shortened as well as the replication of the virus is accelerating… Regional coordinating engineer for vector control at ARS Occitanie, Isabelle Estève-Moussion would like to point out that what certain sites convey is not to be taken at face value. – like garden centers that promote so-called repellents or so-called revolutionary machines to ward off the tiger mosquito, as Dis-Leur explained to you HERE.

Reinforced entomological and medical surveillance

“There is no orange or red vigilance in mainland France, as a well-known site claims, which in reality is taking advantage of the situation to sell combat devices. For good reason: “The tiger mosquito only survives from one summer to the next in egg form and therefore cannot keep tropical diseases. We leave each spring with a stock of mosquitoes that have not (yet) encountered tropical diseases. If he sends the dengue, le zika ou le chikungunya it is when he will meet them by biting an already infected person”, she enlightened.

56 cases imported into Occitania in 2022

Obviously, ARS Occitanie will strengthen entomological and medical surveillance. And also awareness to avoid at least limit the chains of contamination. The figures for 2022 are telling. Even though they are “weaker than in 2019 and 2020”highlighted Isabelle Estève-Moussion, they demonstrate that this insect cannot be eradicated: last year (probably because there were no major epidemics in tropical countries), the ARS counted 56 imported cases but also five outbreaks of autochthonous dengue fever.

“For the first time, outbreaks in the Hautes-Pyrénées; PO. ; Haute-Garonne and Tarn-et-Garonne”

This gave rise to 161 field surveys and 150 treatments. “For the first time, we had outbreaks in the Hautes-Pyrénées; PO. ; Haute-Garonne and Tarn-et-Garonne. It was unexpected because we thought these territories were less colonized…” In case of suspicion of contamination case, “we wait between seven and ten days, the incubation time of the disease, and we conduct an investigation.”

On the phone with the people concerned. In the field with an operator who will check for the presence of “tiger” and we “kill as soon as possible to avoid further contamination”, further specifies Isabelle Estève-Moussion. Who recommended, when one returns from vacation from a region infested with tiger mosquitoes, to continue to protect oneself for at least seven days with repellent, the time of a possible incubation. To prevent an Occitanie mosquito from biting and transmitting the disease you may be carrying…

Sand in cemeteries

The fight is being done step by step… In the Hautes-Pyrénées as elsewhere, the ARS even recommends that communities dry out with sand the small collections of water which are numerous there and which are all potential breeding grounds for the tiger mosquito. . Because, obviously, among the good practices, it should be remembered to avoid leaving the slightest container of stagnant water within reach of spawning. On the side of the ARS, it is explained that awareness will be intensified with individuals, garden centers, colleges, at festivals…

A toy, a cup, even a cork or a bamboo cup is enough! And we often forget it but a gutter; a poorly repaired pipe, a drain or a water collector (to overcome this, it can be covered with a weighted mosquito net, for example) are used as desired. Although, a priori, the early and exceptional drought and the limitation of watering should disadvantage the proliferation of the “tiger”, it “going from the mobilization of all to limit the risks”concludes Didier Jaffre.

Olivier SCHLAMA

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