Serological evidence of arboviral infection and self-reported febrile illness among U.S. troops deployed to Al Asad, Iraq.

Understanding the epidemiology of current health threats to deployed U.S. troops is important for medical assessment and planning. As part of a 2004 study among U.S. military personnel deployed to Al Asad Air Base, in the western Anbar Province of Iraq, over 500 subjects were enrolled, provided a blood specimen, and completed a questionnaire regarding history of febrile illness during this deployment (average approximately 4 months in country). This mid-deployment serum was compared to pre-deployment samples (collected approximately 3 months prior to deployment) and evaluated for seroconversion to a select panel of regional arboviral pathogens. At least one episode of febrile illness was reported in 84/504 (17%) of the troops surveyed. Seroconversion was documented in nine (2%) of deployed forces tested, with no association to febrile illness. Self-reported febrile illness was uncommon although often debilitating, and the risk of illness due to arbovirus infections was relatively low.