Pentagon fights bugs afflicting deployed troops

By Janet McConnaughey

NEW ORLEANS — Fluorescent rodent feces, a promising new mosquito repellant and a better flytrap are all part of a war on bugs designed to protect U.S. troops around the world.

Researchers in the Pentagon’s Deployed Warfighter Protection Research Program highlighted pest-fighting innovations this week at the American Mosquito Control Association convention attended by some 800 scientists and insect control experts. Their aim: to take no prisoners among disease-carrying flies, mosquitoes and other bugs that threaten Americans in uniform abroad.  Even the common fly is counted among the enemy.

“When you’re deployed, I would say 90 percent of all soldiers, service members, are going to have issues with filth flies,” said Army Lt. Col. Jason Pike, executive officer of the 65th Medical Brigade’s Force Health Protection and Preventive Medicine program headquartered in South Korea.
“Filth flies carry many organisms which cause diarrhea … It might not be fatal, but one soldier out of commission affects a lot of other people,” he said.

Begun in 2004, the Deployed Warfighter Protection Research Program dispenses $5 million a year to find new ways to combat disease-carrying insects that threaten the troops — applications that ultimately could protect the public at large.

Military-driven research has produced past innovations against malaria and dengue and helped develop DEET, a key ingredient in most modern repellants. It even has led to chemical-treated fabrics that ward off ticks and mosquitoes.

Fighting bugs is a “global perpetual need,” said program coordinator Graham B. White of the Armed Forces Pest Management Board. “Even if nobody went to war for a long time, these things would still need to be developed.”

He said small insecticide sprayers developed through the program are now in use. The program also backed testing that secured recent Environmental Protection Agency approval of an insecticide spray that is highly toxic at low doses to adult mosquitoes but safe for mammals.

Now Navy Corpsman Joe Diclaro II is taking aim at the housefly. “I like to think of it as a death device,” Diclaro said of a fold-up flytrap designed to ship flat and be rolled into bug-catching tubes in the field.

For starters, he changed the color of the trap.

“Almost everything on the market is yellow,” said Diclaro, who is working on a doctorate in medical entomology at the University of Florida in conjunction with the Agriculture Department’s Mosquito and Fly Research Unit.

When Diclaro released house flies in a dark tunnel between boxes lit in different colors, he found flies prefer blue or white over yellow.

So his trap is made of blue signboard. Tests show it has killed about 3,000 flies in 24 hours. Diclaro said his university’s technology office has applied for a patent.

The research is among nearly three dozen studies funded by the Pentagon program since 2004.

Stephen Duke, of the National Center for Natural Products Research in Oxford, Miss., described possible bug repellents derived from American beautyberry, a shrub common to the Gulf coast. Duke said work began after a botanist remarked that relatives had rubbed farm mules with beautyberry leaves for bug protection.

Two colorless, odorless compounds in the leaves — callicarpenal and intermedeol — seem about as good as DEET against mosquitoes and repel black-leg ticks and fire ants, Duke said. He said a decision on possible commercial uses is still a few years away.

The fluorescent feces are being used at Louisiana State University to learn whether sandflies can be killed by feeding sand rats a chemical harmless to the rodents but lethal to larvae that eat their feces.

Leishmaniasis, which causes disfiguring open sores and is spread by sandfly bites, is an enormous concern in the Middle East, White said. The disease infects an estimated 2 million people a year, according to the World Health Organization.

More than 2,000 U.S. troops in Iraq and Afghanistan have suffered from the disease, said Kenneth Linthicum, director of the Agriculture Department’s Center for Medical, Agricultural and Veterinary Entomology.

To show that something eaten by a rodent could affect a sandfly, LSU researchers fed hamsters a dye that glows hot pink under fluorescent light. Sandfly larvae that ate the rodents’ feces glowed, too.

They then fed hamsters two different chemicals known to kill sandfly larvae. Larvae ate their feces and died.

The fluorescent bait is being tested in Kenya and more work is planned on it, said researcher Thomas Mascari, a postdoctoral student in entomology.  “In 2010, we’ll be going to Egypt to work with the Navy,” he said.