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

Video
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.

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.)


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