It’s impossible to hide from a female mosquito — she will hunt down any member of the human species by tracking our CO2 exhalations, body heat, and body odor. But some of us are distinct “mosquito magnets” who get more than our fair share of bites. Blood type, blood sugar level, consuming garlic or bananas, being a woman, and being a child are all popular theories for why someone might be a preferred snack. Yet for most of them, there is little credible data, says Leslie Vosshall, head of Rockefeller’s Laboratory of Neurogenetics and Behavior.
This is why Vosshall and Maria Elena De Obaldia, a former postdoc in her lab, set out to explore the leading theory to explain varying mosquito appeal: individual odor variations connected to skin microbiota. They recently demonstrated through a study that fatty acids emanating from the skin may create a heady perfume that mosquitoes can’t resist. They published their results in Cell.
“There’s a very, very strong association between having large quantities of these fatty acids on your skin and being a mosquito magnet,” says Vosshall, the Robin Chemers Neustein Professor at The Rockefeller University and Chief Scientific Officer of the Howard Hughes Medical Institute.
A tournament no one wants to win
In the three-year study, eight participants were asked to wear nylon stockings over their forearms for six hours a day. They repeated this process on multiple days. Over the next few years, the researchers tested the nylons against each other in all possible pairings through a round-robin style “tournament.” They used a two-choice olfactometer assay that De Obaldia built, consisting of a plexiglass chamber divided into two tubes, each ending in a box that held a stocking. They placed Aedes Aegypti mosquitoes — the primary vector species for Zika, dengue, yellow fever, and chikungunya — in the main chamber and observed as the insects flew down the tubes towards one nylon or the other.
By far the most compelling target for Aedes aegypti was Subject 33, who was four times more attractive to the mosquitoes than the next most-attractive study participant, and an astonishing 100 times more appealing than the least attractive, Subject 19.
Source: Read Full Article