Do Mosquitoes Keep Biting You? Your Soap May Be Contributing To It, Study Finds

Do mosquitoes keep biting you more than others? The soap you're using may have something to do with it, researchers say.

In a study, which was published Wednesday in iScience, a team of researchers looked at the impact soaps have on making people less or more attractive to mosquitoes. Some people seem more attractive to mosquitoes than others, and this may have something to do with their "odor print."

"The abundance of volatile organic compounds (VOCs) derived from the hosts' metabolism or produced by the activity of their associated microbiome constitutes an olfactory 'odor print' that will enable mosquitoes to discriminate between hosts of different species and between individuals within the same species," the authors wrote.

What some people may not know is that mosquitoes don't just snack on our blood; they rely on nectar as well, noted Virginia Polytechnic Institute and State University (Virginia Tech). With many people using flower or fruit-scented soaps, the question is whether the scents are actually impacting mosquitoes' "host selection process."

To find out, the researchers studied the unique odor profiles of four participants in two stages: unwashed and after washing with popular soap brands Dial, Dove, Native and Simple Truth — the soaps that more than 50% of people in the U.S. preferred in 2019.

The soaps "significantly" changed the hosts' olfactory signature, the researchers said. Some 60% of the odors came from soap and not natural body odors, study co-principal investigator Clément Vinauger, of Virginia Tech, said in a release.

The team found that certain soaps increased or decreased the hosts' attractiveness.

"Out of the four soaps tested here, the Dove and Simple Truth body wash significantly increased the attractiveness of some but not all volunteers, suggesting an interactive effect between the host's olfactory profile and the soap's chemistry," the authors wrote.

Overall, the results show how the host's and soap's scent interact to change mosquitoes' attractiveness to their odor. But "not all soaps have the same effect on all volunteers." Perhaps, the combination of our own unique scents and that of the soaps we use may contribute to whether mosquitoes find our scents attractive or not.

"Just by changing soap scents, someone who already attracts mosquitoes at a higher-than-average rate could further amplify or decrease that attraction," Vinauger said.

For instance, in the case of volunteer one, fewer mosquitoes landed on them when they washed with Dial, Simple Truth or Native soaps compared to the unwashed state. But more mosquitoes landed on volunteer three when their scent was "washed" with Dove or Native brands.

"Trying different soaps is important because we are showing that it's really the combination between your natural odor and a specific soap that matters," Vinauger explained.

There's also the fact that soaps aren't the only scented things that may contribute to this reaction. We also use other scented items like laundry detergents and deodorants.

The researchers now aim to widen the work with more people and more soap varieties. Their latest work "represents a crucial first step" in finding new ways to reduce mosquito bites.

It could potentially lead to the development of soaps that can help people become less attractive to mosquitoes. One interesting finding in the study is that the soap that decreased attractiveness was coconut-scented.

As small as they are, mosquitoes aren't just a nuisance. They are actually the deadliest animal in the world, killing hundreds of thousands of people in the world each year through mosquito-borne diseases. New avenues to prevent potentially harmful mosquito bites are essential to keeping the threat at bay.