1. State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Chinese Center for Disease Control and Prevention, Changping, Beijing 102206, PR China
2. Beijing Center for Diseases Prevention and Control, Beijing, PR China
3. School of Biology and Food Sciences, Shangqiu Normal University, Shangqiu, Henan 476000, PR China
4. Shanghai Institute for Emerging and Re-emerging Infectious Diseases, Shanghai Public Health Clinical Center, Shanghai 201508, PR China