1. Maryland Air National Guard, 175th Medical Squadron, 175th Wing, Baltimore, MD 21220
2. Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205
3. Air Force Institute for Environmental, Safety and Occupational Health Risk Analysis, Brooks Air Force Base, San Antonio, TX 78235-5123
4. Department of Defense Global Emerging Infections Surveillance and Response System, Division of Preventive Medicine, Walter Reed Army Institute of Research, Silver Spring, MD 20910-7500