4Chu CM, Poon I.LM , Cheng VCC, et al. Initial viral load and the outcomes of SARS[J]. Can Med Assoc J, 2004,171 (11).:1349- 1352.
5Leong HNam , Ang B, Earnest A, et al. Investigational use of ribavirin in the treatment of severe acute respiratory syndrome, Singapore, 2003 [J]. Trop Med Int Health, 2004, 9 (8):923-927.
6Poutanen SM,Low DE, Henry B, et al. Identification of severe acute respiratory syndrome in Canada[J]. N Engl J Med, 2003,348(20) : 1995-2005.