Sand flies infect U.S. forces with parasite that leaves them with 'Baghdad Boil'

What happens when a sand fly gets a "blood meal?" Walter Reed entomologist Ed Rowton offers his arm as bait to a group of harmless sand flies, and explains how the insects develop.
By Eric Athas
Tuesday, June 22, 2010

Mason Alsaleh was sound asleep when he was attacked at a U.S. Army outpost in northwest Iraq.

What happened that August night last year left the 48-year-old interpreter disfigured and unable to sleep, his mind muddled with paranoia, his temper short.

But Alsaleh's injuries -- including what look today like third-degree burns on his neck and arm -- weren't caused by gunfire or an explosion. His enemy that night was a tiny insect that injected a flesh-eating parasite into his skin.

Alsaleh, a Jordanian-born military contractor who works for Falls Church-based Global Linguist Solutions, is a victim of leishmaniasis, a disease carried by sand flies that is sometimes called Baghdad Boil. He remembers that when he first got to his mattress in an old building on a contingency base, it was covered in sand flies. He brushed them away.

"It looked like a bug bite," Alsaleh said of the lesions he got on his neck and elbow while the brigade he was working with was based northwest of Mosul. "And it grew and grew and grew, and then started to ooze. Then it gets bigger and starts to ooze again."

The disease, which the World Health Organization says affects 12 million people worldwide, received considerable media and political attention in 2003 during the U.S. invasion of Iraq, when hundreds of soldiers began to spot red bumps on their skin that swelled for weeks before rupturing into seeping wounds. The number of cases dropped to a handful a month by last year, but as more U.S. troops make their way into Afghanistan, doctors and military personnel are warning that the number of cases could tick back up.

Although it's not commonly found in the United States, leishmaniasis is considered endemic in 88 countries and is most prevalent in Afghanistan, Brazil, Bangladesh, India, Nepal, Sudan, Bolivia, Peru, Saudi Arabia and Syria.

When an infected sand fly bites a human, it injects the parasite under the skin, explains Col. Glenn Wortmann, chief of the Infectious Diseases Service at Walter Reed Army Medical Center. Ironically, the parasite stays alive by hiding inside the human body's center of immunity: white blood cells.

"They multiply, they burst out of that macrophage [white blood cell], infect other macrophages, and there's a progressive infection, eventually causing an ulcer in the skin," said Wortmann.

But Alsaleh discovered that the treatment he began in March was almost as traumatizing as the disease itself. The medication that is commonly recommended by doctors is Pentostam, which is administered in 20-injection doses and is "associated with a tremendous number of side effects," said Wortmann.

Most patients who use Pentostam are plagued for months by an aggravated pancreas and liver, as well as severe muscle and joint pains, said Wortmann. It isn't approved by the Food and Drug Administration: U.S. military patients can get the drug only at Walter Reed, and civilians such as Alsaleh must obtain it through the Centers for Disease Control and Prevention.

Other methods used to get rid of Baghdad Boil include a pill called fluconazole, sold under the name Diflucan, which Wortmann said is normally used for fungal infections. For leishmaniasis, it's taken once a day for six weeks, but it's not nearly as effective as Pentostam, said Wortmann.

In September 2003, one of the highest months of leishmaniasis infection among U.S. troops in the past seven years, the Defense Department issued a memorandum asking health-care personnel to "increase their level of suspicion for this disease among redeploying personnel from Afghanistan, Iraq and other areas where leishmaniasis is endemic and sandflies are prevalent."

Soldiers were required to apply a DEET-based product to their bodies and to treat their uniforms with a repellent called permethrin. Col. Peter J. Weina, the director of the Leishmania Diagnostics Laboratory at the Walter Reed Army Institute of Research in Silver Spring, said those rules, along with having more soldiers sleeping in buildings rather than in tents, have reduced the number of infections.

He also said that military medical personnel initially were much more vigorous in searching out, diagnosing and reporting cases than they are now, because in 2003 they didn't know which strain of leishmania parasites they were battling. Since then, they've learned that the vast majority of the parasites in Iraq are leishmania major, a type that isn't as dangerous as strains found in other regions of the world.

"The numbers are going down," said Weina. "But how complicated the cases are and the potential devastation that can come out of the disease is higher now than it was even when a larger number of cases were coming out of Iraq."

A neglected disease

Leishmaniasis is more common in Afghanistan than in Iraq, according to the World Health Organization, which lists it as one of the most neglected tropical diseases in the world. And the infected sand flies there are armed with leishmania major parasites more menacing than their counterparts in Iraq, as well as leishmania tropica, a more persistent and hostile species that causes bigger boils.

Leishmaniasis has many faces.

Both leishmania major and leishmania tropica cause the cutaneous form of the disease, which can produce lingering boils such as the ones that popped up all over Mason Alsaleh's body. Sometimes this form of the disease will result in much smaller lesions that vanish over time.

The visceral strain, most commonly caused by leishmania donovani, leishmania infantum and leishmania chagasi, strikes its victims' liver, spleen and bone marrow, and is deadly if untreated. Symptoms vary, but visceral leishmaniasis can cause "persistent fever for weeks on end, 20 to 30 pounds of weight loss, big liver, big spleen," said Wortmann. If it's diagnosed early enough, there is a simple, FDA-approved drug for this type of leishmaniasis called AmBisome.

And the most terrifying form -- mucocutaneous, caused by leishmania braziliensis -- gnaws away at the faces of the infected.

Cutaneous leishmaniasis starts out looking like a mosquito bite; a month or two after the initial sand fly bite, it breaks open into a volcano-like lesion. And Wortmann said, although it's a rarity, he has seen cases where it took almost a year before the parasite began its siege.

About 10 months after he was bitten, Mason Alsaleh is still struggling with the impact of this disease. His lesions are no longer oozing. But the interpreter, who has returned to his home in Acworth, Ga., said he continues to suffer from insomnia, chest pain and shortness of breath; his doctors tell him these symptoms are possibly side effects of the medications he has taken. His condition has kept him from returning to work since he was evacuated from Iraq in January.

He's eager to go back, though he is concerned about what leishmaniasis -- or Pentostam -- might have done to his mind. (Malaise is listed as a common side effect of the drug.)

"I'm paranoid about it, I'm worried about it, I don't feel the same way I was when I was in Iraq," said Alsaleh, who had never heard of the disease before getting his diagnosis from an Iraqi doctor. "And I have a short temper; anything gets on your nerves. For the longest time, I didn't know what was going on. It does affect you mentally and it does affect you psychologically. . . . It is affecting our soldiers; it's affecting everyone who is going overseas to Afghanistan and Iraq right now."

At the National Institutes of Health in Bethesda, David Sacks is working with researchers to prevent leishmaniasis before it strikes.

"There are currently no vaccines against leishmaniasis; that's the bottom line, but there's a lot of research," said Sacks, chief of the NIH's Intracellular Parasite Biology Section. He said the Infectious Disease Research Institute in Seattle has a potential vaccine in the first phase of clinical trials.

Victor Linscomb, of Tulsa, Okla., has seen many times just how savage this parasite can be.

The 59-year-old aircraft mechanic, who is the director of the nonprofit 1-2-3 International, travels to Nicaragua about every three months to deliver medical services and supplies. In the past five years, Linscomb estimates he has seen at least 500 cases of leishmaniasis.

He said the disease is so complicated to treat that there's very little his group can do for victims; the closest health clinic takes two days to get to.

He can't shake 22-year-old Santos Flores from his mind.

"Her cutaneous is now becoming mucocutaneous, and her nose is becoming infected and the cartilage will continue to disintegrate until it caves in," he said.

In the northern Nicaraguan jungle where Flores lives, Linscomb said, the locals have their own diagnosis. They believe her mother was cursed by a shaman. The leishmaniasis, they say, was caused by that curse.

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