1. Division of Infectious Diseases, Department of Internal Medicine, The University of Texas Health Science Center at Houston, Fannin St, Houston, TX 77030, USA
2. Department of Infectious Diseases, Infection Control and Employee Health, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
3. Division of Infectious Diseases, Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA