1. Guangxi Key Laboratory of Major Infectious Disease Control and Biosafety Emergency Response, Guangxi Center for Disease Control and Prevention, Nanning, People’s Republic of China
2. State Key Laboratory of Infectious Disease Prevention and Control (SKLID), Chinese Center for Disease Control and Prevention (China CDC), Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Beijing, People’s Republic of China
3. Department of Public Health, University of Tennessee, Knoxville, TN, USA