1. From the Department of Medicine, University of Southern California School of Medicine, Los Angeles (P.F.B., P.T.D.); the Division of Tuberculosis Elimination, Center for Prevention Services, Centers for Disease Control, Atlanta (A.B.B., D.E.S.); and Tuberculosis Control, County of Los Angeles Department of Health Services, Downey, Calif. (P.T.D.). Address reprint requests to Dr. Barnes at HMR 904, University of Southern California School of Medicine, 2025 Zonal Ave., Los Angeles, CA 90033.