Kimberley K. Fox, Susan A. Wang, and William C. Levine are with the Division of STD Prevention, National Center for HIV, STD, and TB Prevention, Centers for Disease Control and Prevention, Atlanta, Ga. Carlos del Rio is with the Division of Infectious Diseases, Department of Medicine, Emory University, Atlanta, Ga. King K. Holmes and William L. H. Whittington are with the Division of Infectious Diseases, Center for AIDS and STD, University of Washington, Seattle. Edward W. Hook III is with the Division of Infectious Diseases, University of Alabama at Birmingham and the Jefferson County Department of Health, Birmingham, Ala. Franklyn N. Judson is with Denver Public Health and the Departments of Medicine and Preventive Medicine, University of Colorado Health Sciences Center, Denver. Joan S. Knapp is with the Division of AIDS, STD, and TB Laboratory Research, National Center for Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Ga. Gary W. Procop is with the Section of Clinical Microbiology, Department of Clinical Pathology, the Cleveland Clinic Foundation, Cleveland, Ohio.