1. Stanley Ho Centre for Emerging Infectious Diseases, The Chinese University of Hong Kong, Shatin, Hong Kong, China
2. Special Preventive Programme, Centre for Health Protection, Department of Health, Hong Kong Special Administrative Region Government, Hong Kong, China
3. Hong Kong Tuberculosis, Chest, and Heart Diseases Association, Hong Kong, China
4. Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Shatin, Hong Kong, China
5. Department of Infectious Disease Epidemiology, Imperial College London, London, United Kingdom