PHILADELPHIA, Dec. 5 — Hundreds of American troops in Iraq have been infected with a parasite spread by biting sand flies, and the long-term consequences are still unknown, Army doctors said Friday. The resulting disease, leishmaniasis, has been diagnosed in about 150 military personnel so far, but that is sure to climb in the coming months, the doctors said. All have only the skin form of the disease, which creates ugly "volcano crater" lesions that may last for months, but usually clear up by themselves. None have developed the visceral form that attacks the liver and spleen and is fatal...