Sara A. Quandt is with the Department of Epidemiology, Division of Public Health Sciences, Wake Forest School of Medicine, Winston-Salem, NC. Phillip Summers, Chaya R. Spears, and Thomas A. Arcury are with the Department of Family and Community Medicine, Wake Forest School of Medicine. Werner E. Bischoff is with the Department of Internal Medicine, Section on Infectious Diseases, Wake Forest School of Medicine. Haiying Chen is with the Department of Biostatistical Sciences, Division of Public Health...