1. School of Public Health Shandong University, Wenhuaxi Road, Shandong 250012, People’s Republic of China.
2. Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, State Key Laboratory for Infectious Disease Prevention and Control, 155 Chang-Bai Street, Changping District, Beijing 102206, People’s Republic of China.
3. Center for Diseases Control and Prevention of Guangdong Province, Guangzhou 510300, People’s Republic of China.
4. Emerging Pathogens Institute, University of Florida, Gainesville, FL 32610, USA.
5. State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, People’s Republic of China.