Mosquito season in france: what influences how prone you are to bites?

Mosquito season in france: what influences how prone you are to bites?


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It is not just an urban myth: some people really are more prone to mosquito bites than others, a new study has found. With mosquito season upon us in France, we explore how to avoid the


worst of it. The study by the Johns Hopkins University in the US looked into mosquito behaviour, particularly with a view to the situation in Africa, where mosquitoes cause the deaths of


400,000 people a year as a result of their spread of malaria. The researchers constructed a giant ‘mosquito arena’ in Zambia and filled it with 200 female mosquitoes (the males do not bite).


The species were _Anopheles gambiae_, which often carry malaria (although there are 3,600 species of the insect overall). Six tents were installed around the arena, with a pipe connecting


them to it. A volunteer spent six nights in each tent, in research conditions. Each volunteer and tent was equipped with tools to monitor their average skin temperature and other factors,


and an infrared camera counted the number of mosquitoes in the tent. The goal was to identify which person would attract the most mosquitoes into their tent, and why. SOME MORE ATTRACTIVE TO


MOSQUITOES THAN OTHERS Researchers discovered 40 relevant chemicals over the course of the study - the results of which were published in the SCIENTIFIC JOURNAL CURRENT BIOLOGY. They found


that one of the participants was much more likely than the others to attract the insects, with as many as 160 of the 200 mosquitoes recorded in their tent at once (compared to just a few


dozen in others). RISK FACTORS: DIET, HEALTH, HYGIENE The main reason behind it? Carboxylic acid levels, which are partly linked to a person’s diet. Carboxylic acids are molecules secreted


by bacteria on the skin. * The volunteer attracting the most mosquitoes emitted the highest amount of these acids * The least-targeted volunteer emitted relatively few carboxylic acids, but


three times more eucalyptol, synonymous with a diet rich in plants. Didier Fontenille, director of research at the _Institut de recherche pour le développement_ (IRD), said: “Our smell is in


fact related to what we eat.” But researchers say it also depends on: * Hygiene * Genetics * Bacteria on our skin * The state of our health The study found that other risk factors include:


* Not washing your feet before bed. Unwashed feet have more bacteria and therefore attract more mosquitoes. * Pregnancy. Pregnant women are also more likely than average to be bitten. Conor


McMeniman, assistant professor at Johns Hopkins Bloomberg School of Public Health and Johns Hopkins Malaria Research Institute and senior author of the study, COMMENTED: “These mosquitoes


typically hunt humans in the hours before and after midnight. “They follow scent trails…emanating from humans, and typically they’ll…bite between around 22:00 and 02:00. “We wanted to assess


mosquito olfactory preferences during the peak period of activity when they're out and about and active, and also assess the odour from sleeping humans during that same time window.”


He continued: “We don’t really know yet exactly what aspect of skin secretions, microbial metabolites, or breath emissions are really driving this, but we’re hoping we’ll be able to figure


that out in the coming years.” RESEARCH LIMITS? Dr McMeniman added that in future years, further research could help to develop mass traps using imitation human odour to capture mosquitoes


and reduce the incidence of malaria. The same idea could also help to create more effective repellents. However, Anna-Bella Failloux, mosquito specialist at the Institut Pasteur, TOLD _LE


FIGARO_ that “the results are only valid for [this species of mosquito], so we can’t generalise the findings across the 3,600 species that we know of”. But Dr Fontenille said that the study


was “very robust and rigorous”. MOSQUITOES IN FRANCE The study comes as mosquitoes, and especially tiger mosquitoes, are becoming more prevalent in France. The main concern about tiger


mosquitoes is that they can carry several severe diseases, including dengue fever, zika, and chikungunya. These diseases are usually not associated with France and used to only affect people


who had travelled to an at-risk area. READ ALSO: FRANCE WARNS OF INCREASED RISK OF DENGUE FEVER FROM TIGER MOSQUITOES However, more cases of ‘native’ dengue have recently been reported. In


July 2022, five native cases of dengue were detected in the Provence-Alpes-Côte d'Azur (PACA) and Occitanie regions. A ‘native’ or ‘indigenous’ case means that it was identified in


people who had not previously travelled to an international at-risk area, and the infection came from a tiger mosquito already within France. This has led to the health authority_ la


Direction générale de la santé_ (DGS) warning health professionals and the public to be alert to the increased risk. HOW CAN YOU STOP MOSQUITOES FROM SPREADING? France’s health ministry


said: “Prevention of bites and fighting the spread of mosquitoes is essential to limit epidemics.” The main way to stop them from spreading is to remove any containers or areas of stagnant


water in your garden or outside space, as this is where the mosquitoes lay their eggs. You are advised to empty: * Plastic outdoor containers * Blocked gutters * Flower pot stands * Tools


and other gardening items after rain (or store them away beforehand) * Any other areas of standing water Showering or washing before you go to sleep, and using insect repellent in your


sleeping area, can also keep them away. RELATED ARTICLES MOSQUITOES IN FRANCE: A SCIENTIST'S ADVICE FOR KEEPING THEM AWAY FRANCE’S MOSQUITO SEASON IS HERE. HERE ARE TIPS ON HOW TO AVOID


THEM TIGER MOSQUITOES: HOW YOU CAN HELP STOP THEIR SPREAD IN FRANCE