1. BSL-3 Laboratory, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, China
2. Department of Respiratory and Critical Care Medicine, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, China
3. Department of Epidemiology, School of Public Health, Southern Medical University, Guangzhou, China
4. Guangdong Center for Disease Control and Prevention, Guangzhou, China