Researchers say cream could be ‘home run’ in skin lesions fight
ARLINGTON, Va. — Military medical researchers are working with a cream that can, in 10 to 20 days, heal lesions caused by bites from sand flies common in Iraq and Afghanistan.
The cream, which contains the antibiotic paromomycin, treats cutaneous leishmaniasis, a skin disease that has afflicted at least 2,000 U.S. servicemembers who have served in the region.
Researchers are seeking federal approval for the treatment, said Army Col. Alan Magill, a physician specializing in infectious diseases at Walter Reed Army Institute of Research (WRAIR) in Washington.
If the Federal Drug Administration approves the topical cream, it will be only the second treatment for the disease in 50 years of global research, Magill, the U.S. military’s leading leishmaniasis expert, said in a recent telephone interview.
And the cream would be far less costly, time-consuming, difficult, and painful to administer than Pentostam, the sole drug available now, Magill said.
Leishmaniasis is found worldwide, but especially in the Middle East and Asia. It takes hold when infected sand flies bite people who are sleeping on the ground or otherwise working in very dirty, sandy environments.
Human cases of leishmaniasis mostly fall into one of two categories: cutaneous, which causes skin lesions that vary from the size of a pencil head to larger than the bottom of a soda can; and visceral, a far rarer and more serious variation that attacks the internal organs.
The U.S. military has only recorded five post-9/11 cases of visceral leishmaniasis, with three of those cases coming from soldiers deployed to Afghanistan and the other two from Iraq, Magill said.
But cutaneous leishmaniasis is much more common.
“We’ve logged roughly 2,000 cases since Iraq was started in 2003,” Magill said.
Because leishmaniasis has “hot spots,” “about 90 percent” of those recent cases have been seen among servicemembers deployed to northern Iraq around Mosul and Tal Afar, Magill said. These areas have been hot spots for centuries, he said.
Unlike visceral leishmaniasis, whose victims fall sicker and sicker without treatment and then die, the sores caused by cutaneous leishmaniasis eventually heal without treatment, Magill said.
That healing, however, can take months or even years.
And depending on the size of the sores, the resulting scarring “can be very disfiguring,” especially because many outbreaks occur on the face, Magill said.
Unfortunately, the only treatment for cutaneous leishmaniasis “almost rivals the disease” for misery, Magill said: 10 to 20 days of intravenous Pentostam drips, which produce a host of uncomfortable side effects and require a stay in one of the only two hospitals licensed to administer it, Walter Reed and Brooke Army Medical Center in San Antonio, Texas.
There are currently six servicemembers undergoing treatment with Pentostam at Walter Reed right now, “and they are not happy campers,” Magill said.
WRAIR researchers recently estimated that cutaneous leishmaniasis has cost U.S. taxpayers “in the neighborhood of $40 million,” including the cost of Pentostam treatments, work time lost by patients, the cost of evacuating troops from the field, and so on, Magill said.
The topical cream, on the other hand, “is a whole new ballgame,” Magill said.
“The idea is these tubes of cream can actually go to the front with the medics,” he said. “The soldiers can put the cream on the lesions, cover them with a bandage, and pretty soon, the [sores are] gone.”
The topical cream won’t completely eliminate the need for the harsher drug regime — Pentostam is still the only way of defeating seriously entrenched cases of cutaneous leishmaniasis, Magill said.
However, “as a rough cut, about 50 percent of the people [who come down with the disease] could be treated with the topical” cream, he said.
Because federal law makes testing on deployed troops impossible, WRAIR is conducting field trials on the topical cream in Tunisia, a country particularly hard-hit with leishmaniasis.
Military researchers have found the topical cream to be “a smash hit” with the impoverished locals seeking relief from disease, Magill said.
“For a few hundred thousand dollars, the whole southern half of Tunisia thinks differently about the United States,” Magill said. “We have children named for us over there.”
The WRAIR team is now conducting their second round of Tunisia trials, with a third and final phase planned for next year.
Once that required “Phase III” trial is complete, WRAIR will submit the topical cream to the FDA for approval in 2007, Magill said.
“We know the product works, and we have a manufacturer [Teva USA] who is making the product as we speak,” he said.
“Barring something unforeseen at this point, we have a home run,” Magill said.
Leishmaniasis prevention tips
There’s only one way to prevent leishmaniasis: Keep sand flies from biting. Here are some tips:
Try to limit outdoor activity at dusk and during the evening, when sand flies are most active.
Wear protective clothing, with uniform sleeves turned down and buttoned, and pant legs properly bloused.
Apply insect repellent with N, N-diethylmetatoluamide (DEET) to exposed skin and under the edges of clothing, such as under the ends of sleeves and pant legs. Reapply according to directions (the more you sweat, the more you may need to reapply, but check the bottle first).
Keep uniforms properly treated with permethrin. Make sure to apply after every five washings.
Use permethrin-treated bed netting and screens on doors and windows. Fine-mesh netting (at least 18 holes to the linear inch) is required for an effective barrier against sand flies, which are about one-third the size of mosquitoes.
In the field, try to get your sleeping bag off the ground. If you can’t do that, at least use a ground pad.
If sleeping under cover, sweep all loose dust and dirt from floors. The cleaner your quarters, the fewer the flies.
Do not wear flea collars designed for dogs and cats, even over boots, medical experts warn. The collars are designed to repel common house fleas and there is no evidence they work against sand flies. Meanwhile, the chemicals in the collars have not been tested for safety with humans, and can cause allergic reactions and sores that may become infected.
— Sources: U.S. Army, Centers for Disease Control