1Division of Gastroenterology and Hepatology, Department of Medicine, Stanford University Medical Center, Palo Alto, CA, USA 2Department of Infectious Disease, Nanjing Drum Tower Hospital, Affiliated Hospital of Medical School, Nanjing University, Nanjing, Jiangsu, China 3Institute of Viruses and Infectious Diseases, Nanjing University, Nanjing, China 4Department of Epidemiology and Population Health, Stanford University, Stanford, CA, USA
