1. Department of Preventive Medicine and Biostatistics, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD 20814.
2. Department of Internal Medicine, Division of Infectious Diseases, Naval Medical Center San Diego, 34800 Bob Wilson Drive, San Diego, CA 92134.
3. Department of Internal Medicine, Naval Aerospace Medical Institute, 340 Hulse Road, Pensacola, FL 32507.