Blood, sweat, and beers: investigating mosquito biting preferences amidst noise and intoxication in a cross-sectional cohort study at a large music festival

IntroductionWe live in a world split between mosquito magnets and those lucky enough to remain (nearly) untouched. The reasons why some people attract more mosquito bites than others remain largely mysterious. In the Mosquito Magnet Trial, we investigated differences in mosquito attraction amongst festivalgoers with varying levels of hygiene and intoxication. MethodsOur study was conducted in a slightly steamy pop-up laboratory inside four connected shipping containers at Lowlands Festival in The Netherlands (August 18-20, 2023). Participants completed an anonymous questionnaire on hygiene, diet, and festival-related behaviour (including alcohol uptake and shared sleeping arrangements). Mosquito attraction was measured using a custom designed setup: a transparent cage with perforations where female Anopheles mosquitoes were offered a choice between a sugar-feeder and the participants arm. Mosquitoes could only smell, not bite, the participants arm. Attraction was quantified through video imaging, measuring arm landings relative to total landings. Mosquito attraction was correlated with questionnaire responses and skin microbiota profiles collected from forearm skin swabs. ResultsAmongst the 465 included participants, mosquitoes showed a clear fondness for those who drank beer over those who abstained from the liquid gold (Fold Change 1.35, 95% CI 1.12-1.63, PFDR<0.001). Attraction was also contagious: participants that successfully lured a fellow human into their tent the previous night also proved more enticing to mosquitoes (FC 1.34, 95% CI 1.14-1.58, PFDR=0.002). Meanwhile, skipping the morning showering routine and using sunscreen reduced mosquito attraction (FC 0.52, 95% 0.38-0.70, PFDR<0.001). Streptococci were more abundant on the skin of highly attractive individuals (Puncorrected=0.017), and the overall abundance of malodour associated bacteria was high - possibly reflecting the containers smell. ConclusionThe Mosquito Magnet Trial, to our knowledge the largest study of its kind, was conducted in a loosely controlled setting with a selection bias towards science loving festivalgoers. That said, using our custom designed experimental set-up, we found that mosquitoes are drawn to those who avoid sunscreen, drink beer, and share their bed. They simply have a taste for the hedonists among us.