1. Patrick S. Sullivan, Taylor A. Wimbly, and Eric Hall are with the Department of Epidemiology, Rollins School of Public Health, Emory University, Atlanta, GA. David W. Purcell is with the Division of HIV/AIDS Prevention, National Center for HIV, Viral Hepatitis, STD and TB Prevention, Centers for Disease Control and Prevention, Atlanta. Jeremy A. Grey, Kyle T. Bernstein, and Thomas L. Gift are with the Division of STD Prevention, National Center for HIV/AIDS, Viral Hepatitis, STD and TB Prevention,...