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Bed Bug Resurgence a Multifactorial Issue

— Hygiene, insecticide bans, globalization all contribute

MedpageToday

NEW YORK -- Recent media coverage of bed bug infestations has not exaggerated the issue but instead has reflected an unfortunate consequence of environmental safety and an increasingly mobile society, a skin specialist said here.

The "panic" started 5 years ago in New York City and has since spread across the United States, where bed bug infestations had essentially disappeared in the 1950s. The re-emergence of bed bugs since the beginning of the millennium coincided with bans on potent pesticides (such as DDT) that had kept the insects at bay for decades, , of Baylor College of Medicine, said during a presentation at the American Academy of Dermatology summer meeting.

Insecticides currently in use have little effect on bed bugs, which have developed mutations that increase their immunity to toxins that are safe to use around humans. The same cannot be said of bed bugs' major predator, the cockroach, which is very susceptible to currently available pesticides. The decline of cockroaches as a household nuisance has unintentionally aided the bed bug resurgence.

"Bed bugs were, at some point in time, more of a sign of poor hygienic conditions, but no longer is it true," Rosen told MedPage Today. "Bed bugs can be found in virtually any environment, clean or otherwise."

"They started to multiply -- probably related to the lack of efficacious insecticides -- at the same time as the availability of effective insecticides against cockroaches [became available], along with people adopting 'shabby chic' furnishing, along with the globalization of travel. All of these things have contributed to a widespread, essentially worldwide, epidemic of bed bug infestation, which is no longer limited to any group."

Historically, unsanitary conditions have received most of the blame for bed bug infestations, and that remains true to some extent.

However, the world has become a much smaller place, and people everywhere travel more than in the past, said Rosen. Visitors to the U.S. may bring bed bugs in their luggage or other belongings. Americans returning from travel abroad may bring back more than dirty clothes and souvenirs.

Provided with a fresh, insecticide-free environment, bed bugs can thrive. The insects are incredibly resilient, according to Rosen. In , bed bugs remained viable after spending a week in a suspended state at temperatures as low as -12 degrees C.

Unlike ticks, mosquitoes, wasps, and other insect pests, bed bugs pose little threat to human health. In theory, bed bugs could serve as hosts to several types of disease-causing pathogens, but little compelling evidence suggests that the insects transmit serious illness to humans, said Rosen. Bed bug bites can cause rashes, itching, and even blisters in some cases, but symptoms usually resolve with little intervention other than topical corticosteroids, he added.

"Luckily, bed bugs are not a major health issue in the sense that there has been no reliable report -- ever -- of bed bugs transmitting serious diseases to those they have bitten," said Rosen. "That said, they're a nuisance. The bites don't look nice. They itch. They're annoying."

Someone with pre-existing psychiatric conditions may find bed bug bites particularly disturbing, he added.

Getting rid of infestations is a different matter. The lack of effective insecticides and the bugs' inherent resilience make eradication difficult, especially in the case of major or established infestation. Careful vacuuming, thorough washing of bedding and clothes, judicious use of growth inhibitors, and placement of sticky insect traps all achieve a measure of eradication and may be sufficient in some cases.

Severe infestations will likely require extreme measures, said Rosen. Exposure to high heat (thermal remediation) is the most effective means to achieve eradication. Thermal remediation of a room, a house, or even an entire building is possible but requires a lot of preparation and expense. Affected individuals -- along with pets and anything susceptible to temperatures as high as 140 degrees Fahrenheit -- will have to vacate the premises for awhile.

As an added precaution, people who live or work in a bed bug-infested building may take the antiparasitic drug ivermectin. Bed bugs that bite treated individuals will consume the medication in blood and die.

Travelers can take steps to avoid bringing bed bugs home with them. Precautions include placing luggage in high places away from the bed, check hotel or other bedding for the presence of bed bugs, keep travel clothing separate from other clothing until thoroughly laundered or dry-cleaned after returning home.

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    Charles Bankhead is senior editor for oncology and also covers urology, dermatology, and ophthalmology. He joined MedPage Today in 2007.

Disclosures

Rosen disclosed relationships with Anacor Pharmaceuticals, Castle Biosciences, Merz Pharmaceuticals, Pharmaderm, and Valeant Pharmaceuticals.

Primary Source

American Academy of Dermatology Summer Academy Meeting

Rosen T "Infectious disease and infestations in returned travelers: the Americas. Biting bad: bed bugs" AAD SAM 2015; Focus Session 019.