A recent study revealed that new “super” bedbugs exhibited early signs of resistance to two more types of insecticides, apart from the traditional deltamethrin and other pyrethroid-class insecticides. These insects are being seen everywhere, thanks to global travel and travelers inadvertently carrying the pests on clothing and bags. In fact, a recent report noted that bedbug call-outs increased by 108 percent in London alone. Pest control company Orkin also stressed that bedbug infestation in the U.S. has reached exponential proportions. According to Orkin’s ranking, Baltimore had the worst case of bedbug infestation among 50 major U.S. cities, showing a 9 percent increase since 2015. This was followed by Washington D.C., Chicago, and New York.
Researchers at the Purdue University in Indiana examined 10 populations of bedbugs that were collected and contributed by pest management experts and researchers from various U.S. states. The study showed that three bedbug population exhibited reduced susceptibility to chlorfenapyr after a week of exposure. The researchers also found that five bedbug population showed early signs of resistance to bifenthrin following seven days of exposure.
“In the past, bed bugs have repeatedly shown the ability to develop resistance to products overly relied upon for their control. The findings of the current study also show similar trends in regard to chlorfenapyr and bifenthrin resistance development in bed bugs. With these findings in mind and from an insecticide resistance management perspective, both bifenthrin and chlorfenapyr should be integrated with other methods used for bed bug elimination in order to preserve their efficacy in the long term,” said researcher Ameya D. Gondhalekar in an article in Phys.org.
More studies are needed to determine the cause of insecticide resistance in bedbugs, the scientists said. However, researchers noted that certain measures can be done to help reduce bedbug exposure. “There is a plethora of research that has shown that if insecticides are integrated with additional control measures such as vacuuming, steam or heat, mattress encasements, traps, and desiccant dusts, effective bed bug control can be accomplished and theoretically this should reduce the risk of resistance build-up in populations,” Gondhalekar said.
A pest control expert has also stressed that people should regularly check mattresses and beds for signs of bedbug manifestation. The expert also discouraged buying secondhand mattresses, and urged the public to carefully inspect secondhand furniture before bringing one home.
The findings were published in the Journal of Economic Entomology.
Health risks associated with bedbug exposure
Bedbugs are flat and oval-shaped vectors that reside in the cracks and crevices of beds, and emerge at night to feed on the hosts’ blood. Their shape and small size make pest control challenging. In fact, data from the Bugs Without Borders survey in 2015 showed that 68 percent of pest control professionals cited bedbugs as the most difficult pest to eradicate. Bedbug exposure may pose a threat to the general public, the U.S. Environmental Protection Agency (EPA) noted.
According to the EPA, bedbug bites may trigger severe allergic reactions including anaphylaxis. These insects’ bites may also lead to secondary infections such as impetigo, ecthyma, and lymphangitis. The EPA also cautioned that bedbug infestation may negatively impact the overall mental health. Certain conditions such as anxiety, insomnia and systemic reactions have been associated with bedbug exposure, the EPA added.
A case study published in 2009 also revealed that bedbug infestation may lead to anemia in some rare cases. The case study cited a 60-year-old man who showed signs of iron deficiency despite the absence of risk factors for anemia. Upon inspection, the researchers found that the man was exposed to thousands of bedbugs. The findings appeared in the Canadian Medical Association Journal.