1. Clinical medical Research Center, Children’s Hospital of Nanjing Medical University, Nanjing, Jiangsu 210008, China
2. School of Public Affairs, Nanjing University of Science and Technology, Nanjing, Jiangsu 210094, China
3. School of Elderly Care Services and Management, Nanjing University of Chinese Medicine, Nanjing, Jiangsu 210023, China
4. Infection Control Office, Department of Medicine, the First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, Shaanxi 710061, China
5. Department of Population Health Science and Policy, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
6. School of Public Health, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China