1Department of Medicine and Geriatrics, United Christian Hospital, Hong Kong SAR, China
2Department of Microbiology, Princess Margaret Hospital, Hong Kong SAR, China
3Department of Microbiology, The University of Hong Kong, Hong Kong SAR, China
4Government Virus Unit, Kowloon, Hong Kong SAR, China
5Department of Medicine and Geriatrics, Princess Margaret Hospital, Hong Kong SAR, China
Reprint requests and correspondence: Tai Nin Chau, M.B.B.S., M.R.C.P., Department of Medicine and Geriatrics, United Christian Hospital, 130 Hip Wo Street, Kwun Tong, Hong Kong SAR, China.
Received June 24, 2005; accepted October 10, 2005.