Bedbugs plague homes the world over. But even after they’re gone, their effects on your health may not disappear. A new study traces the problem to their lingering poop.
Bedbug feces contains a chemical called histamine (HISS-tuh-meen). It is part of their pheromones. That’s a mix of chemicals that the insects excrete to attract others of their kind. In people, however, histamine can trigger allergy symptoms. Among these are itchiness and asthma. (Our bodies also naturally release histamine when confronted with an allergy-provoking substance.)
While some treatments can successfully kill off bedbugs, their poop can linger. So the histamine can remain in carpets, furniture upholstery and other household items long after the vermin are gone.
Zachary C. DeVries works at North Carolina State University in Raleigh. As an entomologist, he studies insects. His specialty: urban pests. He and his team shared their histamine data February 12 in PLOS ONE.
They collected dust from apartments in a building with a chronic bedbug problem. Eventually, a pest control company raised the temperature of all of the rooms in the building to a toasty 50° Celsius (122° Fahrenheit). This killed off the bugs. Afterward, the researchers collected more dust from the apartments. They compared all of that dust to some from neighboring homes. These had been free of bedbugs for at least three years.
Histamine levels from dust in the infested apartments was 22 times as high as the amount found in bedbug-free homes! So while the heat treatment had rid apartments of the tiny bloodsuckers, it had done nothing to lower histamine levels.
Future pest-control treatments, the researchers say, might need to start focusing on attacking histamine from any lingering bug poop.