1. Department of Internal Medicine, Warren Alpert Medical School of Brown University, Providence, Rhode Island, USA
2. Division of Infectious Diseases, Warren Alpert Medical School of Brown University, Providence, Rhode Island, USA
3. Department of Laboratory Medicine, the University of Texas M.D. Anderson Cancer Center, Houston, Texas, USA
4. Department of Infectious Diseases, Infection Control and Employee Health, the University of Texas M.D. Anderson Cancer Center, Houston, Texas, USA