1 School of Computer Science and Engineering, Sun Yat-Sen University, Guangzhou, Guangdong, China.
2 Center for Public Health Surveillance and Information Service, Chinese Center for Disease Control and Prevention, Beijing, China.
3 State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang, China.
4 School of Public Health, Peking University, Beijing, China.