1. School of Public Health , Li Ka Shing Faculty of Medicine, , Hong Kong , China
2. The University of Hong Kong , Li Ka Shing Faculty of Medicine, , Hong Kong , China
3. World Health Organization Collaborating Center for Infectious Disease Epidemiology and Control , School of Public Health, Li Ka Shing Faculty of Medicine, , Hong Kong , China
4. The University of Hong Kong , School of Public Health, Li Ka Shing Faculty of Medicine, , Hong Kong , China
5. Laboratory of Data Discovery for Health, Hong Kong Science and Technology Park , Hong Kong , China