Little Big Problem

Bedbugs may be traveling the globe via dirty laundry

thanks to the advent of

cheap travel, bedbugs are thriving. Little research has been done to understand how best to prevent these bloodsuckers from boarding transcontinental flights and returning home with travelers, but you might want to take a hard look at your smelly socks.

Researchers from Britain’s University of Sheffield had reason to suspect that unwashed clothing attracts bedbugs, parasitic insects that find their meals by following human scents.

William Hentley and colleagues wanted to know if our dirty laundry plays a role in the travels of bedbugs. They instructed volunteers wear white cotton T-shirts and socks. Three hours later, the researchers sealed the clothing in ziplock bags, then washed half the sets. Each set of clothing was then put into clean duffel bags.

The experiment used two rooms, identical except that one had elevated levels of carbon dioxide to simulate the presence of a human. The researchers released bedbugs into the rooms. According to the study, published online last month by Scientific Reports, bedbugs were twice as likely to end up in the bags with unwashed clothes than in those containing clean clothes. The elevated carbon dioxide level, which should have fooled the bugs into behaving as if a human was present, was not as strong a draw as dirty laundry.

Because travelers tend to return home with bags full of worn clothing, suitcases are “potential ‘vehicles’ for passive dispersal,” the authors write. Sweat and volatiles—chemicals that evaporate at room temperature, often sending scents wafting through the air—release human odor that, the researchers explain, “may therefore influence host-searching behavior in bedbugs.” That’s a scientist’s way of saying that dirty clothes are an ideal free international flight for bedbugs.

Those wary of bringing home bedbugs might do their laundry before getting on a plane. “Careful management of holiday clothing may be an important strategy in the prevention of bringing home bedbugs,” the researchers conclude.