Bug Buster? New Chemical Compound Could Ward Off Deadly Mosquitoes

June 27, 2011— -- Somewhere in the world, every 45 seconds, malaria claims the life of one child. The large majority of those deaths are in Africa. And they are preventable.

"The most dangerous animal on the planet is the Anopheles gambiae,'' the mosquito that carries malaria, said Dr. Lawrence Zwiebel, a researcher at Vanderbilt University who has been working for the past six years to find a way to repel the deadly insects.

Zwiebel's team has taken a novel approach. Rather than looking for ways to eradicate the insects or disrupt the ecosystem, they sought to change the habits of the ancient pests, their feasting habits, to be precise, by making humans less appetizing to the nasty predators.

Last month, Zwiebel's team announced that they may have hit the jackpot. They identified what's called a behaviorally disruptive olfactory compound that they believe could be thousands of times more effective than the most commonly used insect repellent on the market, DEET.

The compound, which the Vanderbilt scientists have named VUAA1, works by activating all 76 of the insect's odor receptors at once, over-stimulating and confusing the bugs, said Patrick L. Jones, a postdoctoral research fellow working on Zwiebel's team.

Jones likened the experience of a mosquito exposed to the compound to a familiar human experience: "If you step into an elevator, and there's someone with too much perfume on, you are activating only a few smell receptors," said Jones, "but you still want to get out to of there."

"For the mosquito, we'd be activating every single one. That would be very confusing and we think short-circuit their ability to smell (humans)."

If not humans, they would target birds and other mammals not treated with the repellent as their prey. "Mosquitoes are fairly promiscuous," he said.

What's more, Jones said, the compound seems to work on other bugs. "This a potential new repellent that could repel virtually every insect," disease-carrying as well as merely nuisance species.

"No one has ever seen a molecule like this with this type of activity," said Zwiebel. "We're trying to understand why it is able to do what it does."

Researchers hope their findings will lead to repellents that will deter crop-eating pests, which feast on and destroy the world's food sources, as well as flies attracted to human sweat.

The researchers, whose work, in partnership with John Carlson at Yale University, as well as laboratories in Gambia, Kenya and the Netherlands, is funded by the Bill & Melinda Gates Foundation, and the National Institutes of Health, caution that while they are optimistic about their findings, there is a long road ahead before their work begins to save lives – or make your backyard barbecue more comfortable.

It will take at least five years and millions of research and development dollars before a product based on the new compound is approved for sale and becomes available commercially. But when it does, they say, some of the profits from the product will be channeled to offset the costs of supplying the repellent to countries that cannot afford it.