1. From the Department of Medicine, Princess Margaret Hospital, Hong Kong SAR
2. From the Department of Pathology, Princess Margaret Hospital, Hong Kong SAR, China
3. Department of Microbiology, Queen Mary Hospital, Hong Kong SAR, China
4. Department of Medicine, Pamela Youde Nethersole Eastern Hospital, Hong Kong SAR, China
5. Intensive Care Unit, United Christian Hospital, Hong Kong SAR, China
6. Hospital Authority, Hong Kong SAR, China