July 11, 2012

DNA Mapping Used To Pinpoint Bed Bug Explosion

John Neumann for - Your Universe Online

Biologist Toby Fountain, long fascinated with bedbugs, is leading a study to find out why the infamous insects have spread so much in the last decade. Using DNA fingerprinting techniques, he and his colleagues are attempting to track down the origin of the great bed bug explosion.

The global surge in bed bugs, Toby explained, was first documented just after the 2000 Sydney Olympics. “It´s been getting more and more prevalent since then,” says Fountain.

Although the exact figure is difficult to estimate, the cost of the infestations has been placed in the tens of millions. Primarily from lawsuits against hotels that are accused of infestations and leaving their guests to deal with the after effects, reports Victoria Gill ,Science reporter for BBC Nature.

Other lawsuits have been taken out against pest controllers who, if and when a bed bug infestation returns, are accused by customers of failing to do their job properly. This is where Fountain and his study from the University of Sheffield could ultimately settle some expensive arguments.

The DNA fingerprinting techniques pinpoint “signatures” in the DNA of the pest that reveal which particular infestation a bug has come from. “If you´ve picked up bed bugs from a hotel, you could look at the genetic markers of that bed bug and be fairly sure that they came from that place,” Fountain explains.

“And if every pest controller keeps a [sample and a] record of any infestation, we´ll eventually be able find out whether any repeat infestations came from the same place, and whether that pest controller has done his job properly.”

Although still in the process of gathering his bug DNA evidence, Fountain is coordinating pest control teams across London to gather samples and trace the spread of the insects.

Fountain claims London is a “bed bug hotspot” and the psychological trauma the bugs cause is palpable.“People in infested properties get extremely distressed,” he explains. There is even a condition, known as delusory parasitosis, in which people can actually break out in a bite-like rash, apparently caused by the stress of worrying about bed bugs.

Fountain is clearly quite impressed by the sheer hardiness and capabilities of the bugs, despite all the discomfort, cost and upset they cause. The fact that they have been able to spread throughout the globe in such a short time is remarkable.

The blood-sucking insects cannot fly and, since a single human can provide essentially an unlimited amount of food for a colony, finding a new home does not make much sense for their survival. Leaving the comfort of their sofa crevice is actually quite risky. But it seems that bed bugs instinctively search for new places to hide and reproduce.

The genetic techniques being used are just starting to get to the core of how global travel affects bed bug biology. To solve the mystery of bed bugs´ worldwide success, Toby and his colleagues are now starting to work outside of the UK, primarily in Kenya, taking samples from homes in towns around Nairobi, and some smaller villages.

“In Kenya, bed bugs have always been there. So one theory is that that´s where [the UK´s bug resurgence] came from. Another theory is that they´ve always been in the UK, but in little, tiny pockets, and for some reason they´ve exploded out of these pockets in the last 10 years.”

If Fountain and his team find a genetic link between Kenya´s bed bugs and those of the UK, they might be able to solve that part of the puzzle once and for all. “I think we´re getting closer,” the scientist says.