1. School of Population and Public Health, University of British Columbia, Vancouver, BC, Canada
2. State Key Laboratory for Infectious Disease Prevention and Control, and National Center for AIDS/STD Control and Prevention (NCAIDS), Chinese Center for Disease Control and Prevention (China CDC), Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Beijing, China
3. Department of Medicine, Division of Epidemiology, Vanderbilt Institute for Global Health, Vanderbilt University Medical Center, Nashville, TN, USA
4. Chaoyang Center for Disease Control and Prevention, Beijing, China