Bed Bug Weapon Uses Insect's Own Juice

Thank You; Emily Sohn, Discovery News

Researchers have enlisted a new weapon against bed bugs: their own chemical signals. It's first time scientists have used any insect's alarm pheromones as a method of control.

While the new technique probably won't single-handedly solve anyone's bed bug woes, experts say, the research may add to our arsenal of tools for fighting what has become a disturbing nuisance for a growing number of people.

"To control bed bugs, there's not going to be one easy solution," said Joshua Benoit, an entomologist at Ohio State University in Columbus. "We are trying to encourage people to find new and creative ways to kill bed bugs."

Bed-bug infestations have been on the rise in recent years, Benoit said, probably because people travel so much. All it takes is one pregnant female hopping a ride in a suitcase for a new crop of insects to invade homes and apartment buildings.

The tiny critters don't spread diseases, but a single person can easily get a few hundred bites in one night. Those chomps cause intense itching and even scarring in some people.

So far, there is no ideal way to get rid of bed bugs. Pesticide treatments can be expensive, invasive, toxic, and often ineffective. Already, the insects have developed resistance to some of the most common chemicals used to fight them.

In an effort to get the upper hand, Benoit experimented with alarm pheromones -- the chemicals that bed bugs release when they're disturbed or in danger. In turn, their comrades get excited and start scurrying around.

Benoit and colleagues mixed synthetic versions of bed-bug alarm pheromones with desiccant dust, a pesticide that works by drying insects out. In order to work, the bugs need to run directly through the dust.

The researchers placed varying concentrations of these mixtures in Petri dishes and in small enclosures that contained hiding places for the insects. Then they added bed bugs.

Their results, published in the Journal of Medical Entomology, showed that mixtures of alarm pheromones and desiccant dust killed up to 50 percent more bed bugs than did desiccant dust alone. The idea is that the pheromones get the bugs to move around more, making them more likely to run through the dust, which is relatively non-toxic and inexpensive.

"This is the first study of its kind to use alarm pheromones in this manner," Benoit said, "for any insect."

It's still way too soon to recommend that people run out and buy alarm pheromones (which are synthesized for other purposes, including as food preservatives). Outside the confines of a plastic dish, getting bed bugs to run around like crazy is not necessarily a good thing, said Michael Potter, an urban entomologist at the University of Kentucky, Lexington. Bed bugs are notoriously good at getting behind baseboards, inside walls, and into other cracks and crevices.

"Some might run into the apartment next door," Potter said. "Some might run into inaccessible areas."

In one recent incident in Columbus, Benoit said, bed bugs had infested 23 out of 24 units in an apartment building. Residents had to leave their homes for a week while the building was fumigated. Even then, there was no guarantee that the treatment killed all the bugs.

The incident illustrates how important it is to continue learning more about the inner workings of these pests.

"Any new work on bed bugs," Potter said, "is interesting work."

Healthy Forever & Ever

WHO Declares Swine Flu Pandemic

The World Health Organization told its member nations it was declaring a swine flu pandemic Thursday -- the first global flu pandemic in 41 years as infections climbed in the United States, Europe, Australia, South America and elsewhere.

In a statement sent to member countries, WHO said it decided to raise the pandemic warning level from phase 5 to 6 -- its highest alert level -- after holding an emergency meeting on swine flu with its experts.

"At this early stage, the pandemic can be characterized globally as being moderate in severity," WHO said in the statement, urging nations not to close borders or restrict travel and trade. "(We) remain in close dialogue with influenza vaccine manufacturers."

Health officials from Scotland, Indonesia and Thailand previously announced the agency would declare a swine flu pandemic -- a global epidemic -- on Thursday after a teleconference with leading flu experts. Officials at U.N. missions in Geneva also said they expected the imminent announcement of a pandemic.

"It is likely in light of sustained community transmission in countries outside of North America -- most notably in Australia -- that level 6 will be declared," Scotland's Health Secretary Nicola Sturgeon told Scottish lawmakers, adding it would be Thursday.

Indonesian health minister Siti Fadilah Supari said she had been notified by WHO that "today will be declared to be phase 6."

The last pandemic -- the Hong Kong flu of 1968 -- killed about 1 million people. Ordinary flu kills about 250,000 to 500,000 people each year.

Since swine flu first emerged in Mexico and the United States in April, it has spread to 74 countries around the globe.

On Wednesday, WHO reported 27,737 cases including 141 deaths. Most cases are mild and require no treatment, but the fear is that a rash of new infections could overwhelm hospitals and health authorities -- especially in poorer countries.

The long-awaited pandemic announcement is scientific confirmation that a new flu virus has emerged and is quickly circling the globe. It will trigger drug makers to speed up production of a swine flu vaccine and prompt governments to devote more money to containing the virus.

In May, several countries urged WHO not to declare a pandemic, fearing it would spark mass panic.

Panic has already gripped Argentina, where so many people worried about swine flu flooded into hospitals this week that emergency health services have collapsed. Last month, a bus arriving in Argentina from Chile was stoned by people who thought a passenger on it had swine flu. Chile has the most swine flu cases in South America.

In Hong Kong, the government on Thursday ordered all kindergartens and primary schools closed for two weeks after a dozen students tested positive for swine flu.

In Australia, swine flu cases jumped to more than 1,000 on Monday and reached 1,260 by late Wednesday.

WHO says its pandemic announcement would not mean the situation was worsening, since no mutations have been detected in the virus to show it is getting more deadly.

In Edinburgh, Sturgeon told lawmakers that a WHO announcement means countries should immediately activate their pandemic plans.

"A move to level 6 is not a verdict on the severity of the virus," she said. "It simply means that the extent of global spread now fulfills the definition of a pandemic."

Healthy Forever & Ever

Armpits: 'Rain Forests' For Bacteria

Thank You, Lauran Neergaard

Eeeww. There's a zoo full of critters living on your skin -- a bacterial zoo, that is. Consider your underarm a rain forest. Healthy skin is home to a much wider variety of bacteria than scientists ever knew, says the first big census of our co-inhabitants. And that's not a bad thing, said genetics specialist Julia Segre of the National Institutes of Health, who led the research.

Sure they make your sneakers stinky, "but they also keep your skin moist and make sure if you get a wound that (dangerous) bacteria don't enter your bloodstream," she said. "We take a lot for granted in terms of how much they contribute to our health."

People's bodies are ecosystems, believed home to trillions of bacteria, fungi and other microbes that naturally coexist in the skin, the digestive tract and other spots. But scientists don't have a good grasp of which microbes live where, much less which are helpful, even indispensable, in maintaining health.

The NIH's "Human Microbiome Project" aims to change that, recruiting healthy volunteers to learn what microbes they harbor so scientists can compare the healthy with diseases of microbes gone awry -- from acute infections to mysterious conditions like psoriasis or irritable bowel syndrome.

The skin research, published in Friday's edition of the journal Science, is part of that project. Scientists decoded the genes of 112,000 bacteria in samples taken from a mere 20 spots on the skin of 10 people. Those numbers translated into roughly 1,000 strains, or species, of bacteria, Segre said, hundreds more than ever have been found on skin largely because the project used newer genetic techniques to locate them.

Topography matters, a lot, the researchers reported. If a moist, hairy underarm is like a rain forest, the dry inside of the forearm is a desert. They harbor distinctly different bacteria suited to those distinctly different environments. In fact, the bacteria under two unrelated people's underarms are more similar than the bacteria that lives on one person's underarm and forearm.

Mom's advice to wash behind your ears notwithstanding, that spot contained the least diverse bacteria -- 19 species on average. The most diverse spot: the forearm, which averaged 44 species.

How many are supposed to live there? That's not clear yet. Some certainly could be tourists, picked up as we go about our day. When researchers re-checked five of these volunteers a few months later, the bacteria in some spots -- the moist nostril and groin, for example -- proved pretty stable while other spots, including the forearm, had changed quite a bit.

Which are good bugs, and which bad? That depends. A common skin bacteria is Staph epidermidis, found all over the body. Segre said it helps protect us from its nasty cousin, Staph aureus, which about a third of people are thought to carry on the skin or in their nose even if they have no active infection.

But, back to topography, Staph epidermidis itself can harm if it gets under the skin; it's a common trigger of catheter-caused infections.

The research helps lay the groundwork for what doctors really want to know: What's different in the skin of people with diseases such as eczema or psoriasis? Those studies are about to begin, says Dr. Martin Blaser of New York University Langone Medical Center, who is leading one on psoriasis and performed some first-step studies of skin bacteria that helped lead to the NIH's census.

Then there's the scrubbing question, society's antibacterial obsession.

"There's an all-out assault on our normal skin organisms," Blaser noted. "In trying to get rid of the bad guys, are we getting rid of the good guys?"

Segre hopes knowing there are so many bacteria alters how people think about the relationship.

"I'm a mother of two small children; I believe very strongly in sanitation, washing your hands," Segre said. But, "we have to understand that we live in harmony with bacteria and they are part of us as super-organisms ... and not just conceive of bacteria as bad and germs and smelly."

Healthy Forever & Ever