Experts attribute the lack of a problem with infectious diseases during the Gulf War to a comprehensive infrastructure of medical care and preventive medicine efforts.90,185,271,273,293 DOD took measures to minimize infectious disease risk, including strict monitoring of drinking water purity, inspecting food sources and supplies, maintaining field camp sanitation, and instituting an insect vector control program. U.S. service members received booster doses of routine vaccinations, including typhoid, meningococcus and, during the fall, influenza. Immune gamma globulin was used to prevent Hepatitis A, and the small number of troops who entered Iraq near the Euphrates River valley received drug prophylaxis for malaria.

Most of the combat troops were isolated in barren desert locations, distant from rivers, oases, and urban areas. Additionally, maximum troop deployment occurred during the cooler winter months, which provided the least favorable conditions for the transmission of insect-borne diseases.90,185 Indeed, the majority of the 12 individuals who developed viscerotropic leishmaniasis had been deployed to urban areas.145

DOD medical personnel evaluated U.S. service members for several diseases transmitted by insects, including leishmaniasis, sandfly fever, malaria, dengue, Sindbis, West Nile fever, Rift Valley fever, and Congo-Crimean hemorrhagic fever.90,293 As noted, sandfly fever had been a major concern, but no cases were seen during the Gulf War. DOD reports detecting seven cases of malaria and one case of West Nile fever, a mosquito-borne viral illness. No rickettsial illnesses and no cases of other arthropod-borne viral illnesses were identified.

Viscerotropic leishmaniasis (VL) and cutaneous leishmaniasis (CL) are the only endemic infectious diseases demonstrated to cause chronic morbidity among a number of Gulf War service members. These diseases are transmitted through the bites of sand flies; person-to-person infection does not occur. Thirty-two cases of leishmaniasis were diagnosed among U.S. troops, consisting of 12 cases of VL and 20 cases of CL.145,277 CL causes a characteristic ulcerative or nodular skin rash that can persist for more than a year without treatment. And, while VL can be difficult to confirm, it is not considered to be a cause of widespread illness in Gulf War veterans. All veterans diagnosed with VL, except one, have experienced the signs characteristic of the disease.90,146,293

It is unlikely that veterans in the Registry or CCEP who have unexplained illnesses are suffering from VL. The incidence of VL during the Gulf War and the five years since has been low (12 of 697,000), and other sandfly-borne infectious diseases in the troops have been absent.90,278 Additionally, individuals with unexplained illnesses also lack signs and symptoms characteristic of VL. VL can sometimes occur following a prolonged incubation period (more than 18 to 24 months); there is also a risk of activation of latent infections in immunosuppressed persons.65,90,146 To date, DOD and VA report that delayed onset of VL has not occurred.

From August 1990 through July 1991, the U.S. Army deployed approximately 347,000 individuals to the Gulf region. Based on information from U.S. Army field hospitals, the only infectious diseases that caused 30 or more each of approximately 14,000 admissions were pneumonia, intestinal infections, inflammation of the testes and/or epididymus, chicken pox, and kidney infections.342,343

Based on a review of the rates and types of the diseases diagnosed during and after the Gulf War, the Committee concludes it is unlikely that infectious diseases endemic to the Gulf region are responsible for long term health effects in Gulf War veterans, except in a small, known number of individuals.