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Program Overview:
Leishmaniasis is a disease caused by protozoan parasites of the genus Leishmania transmitted by sandflies. An estimated 12 million people worldwide suffer from leishmaniasis with more than a million new cases reported annually, and an estimated 350 million persons at risk. Leishmaniasis is found in areas ranging from the rain forests in Central and South America to deserts in West Asia. Most of the affected countries are in the tropics and subtropics. Leishmaniasis includes a wide spectrum of illnesses, ranging from the self-healing cutaneous form (CL) to a life-threatening visceral disease (VL). The cutaneous form of the disease may result in highly disfiguring lesions or, with certain species of Leishmania present in the New World, can spread to the nasal or oral mucosa causing a form of the disease called muco-cutaneous leishmaniasis. Visceral leishmaniasis is caused by infection of the reticuloendothelial system, including the spleen, liver, bone marrow, and lymph nodes. Untreated visceral leishmaniasis may result in death. CL does not present a mission stopping military operational risk. Instead the uncertainty associated with the inability to diagnose or treat in theatre required hundreds of soldiers to be medically evacuated to CONUS, presenting logistical problems in the current theater of operation in Iraq. In addition, the potential for latent infections impacts military blood supplies since personnel deployed to endemic areas are deferred from providing blood within the military system. In addition, the impact on individual and unit morale is hard to quantify but not insignificant. Soldiers with large ulcerative lesions caused by a "parasite" have a demoralizing effect on other troops.

As of today, over 1100 parasitologically confirmed cases of CL have occurred in US soldiers deployed to Iraq. Current policy is that each infected soldier with significant lesions must be evacuated to the Walter Reed Army Medical Center to receive from 10 to 28 days of intravenous drug therapy with sodium stibogluconate (Pentostam) available in the US under an IND.

Although preventive vaccines and/or prophylactic drugs are often the preferred method of protecting military personnel from infectious disease threats, there currently are no U.S. FDA-licensed prophylactic drugs or vaccines for leishmaniasis. In addition, the leishmaniases are geographic and deployment specific risks that are hard to predict. It is highly unlikely that a preventive vaccine, should it exist, would be employed in US military personnel because of cost/benefit and risk/benefit considerations. The same reasoning holds true for a chemoprophylaxis strategy.

Current thinking on the part of the military Leishmania research leadership is that a vaccine or chemoprophylaxis strategy to prevent infection or disease is not an achievable scientific goal because of limited resources and high scientific barriers, and cannot be implemented to the deployed force because of logistic and cost/benefit considerations. Therefore, the current MIDRP Leishmania research program will not consider or solicit proposals for vaccine or chemoprophylaxis efforts.

Research in Program Area P will focus on the developing an FDA approved systemic, non-parenteral treatment for Cutaneous Leishmaniasis.

Malaria Drugs | Malaria Vaccines | Leishmaniasis