Annual Report 2002–03

醫學院 Faculty of Med i c i ne 分子非典型肺炎研究：由病毒基因排序 至新的檢測方法 S A R S 爆發期間，中大成立了一個跨部門科研小 組，集中研究 SARS 的分子病理學，成員來自生物 化學系、化學病理學系、內科及藥物治療學系、 微生物學系、兒科學系及外科學系。他們是全球 率先公開完整冠狀病毒基因圖譜排列的研究小組 之一，並以之追溯 SARS 的病毒源頭，發現在疫潮 爆發初期，香港已經存在著至少兩個病毒源頭。 小組亦破解了淘大花園病人的病毒基因排序，有 助追蹤 S A R S 病毒的變異，是將來相關研究的基 礎。 小組更憑著過去在血槳脱氧核糖核酸和核糖核酸 ( R N A ) 分析的出色研究基礎，以血漿 R N A 技術 發展出 SARS 的新測試方法，能於病人入院的首天 確定病人是否染上 SARS ，準確度高達八成。根據 血液測試研究顯示，曾接受深切治療的病者的病 毒濃度中位數，比不需深切治療者高出三十倍。 小組進一步把測試技術應用到患 S A R S 的兒童身 上，確定了新測試法的準確性。這個新測試方法 對於 SARS 的監察、診斷和研究有極重要的意義。 Molecular SARS Research: From Virus Genomic Sequencing to New Diagnostics A multi-disciplinary team comprising researchers from the Departments of Biochemistry, Chemical Pathology, Medicine and Therapeutics, Microbiology, Paediatrics, and Surgery was one of the first groups to make the complete genomic sequence of the SARS coronavirus (SARS-CoV) publicly available. They determined the complete genomic sequence of the SARS-CoV strain that was involved in the major SARS outbreak at the Prince of Wales Hospital in March 2003 and discovered that at the outset there were at least two SARS- CoV strains in Hong Kong. They also determined the complete genomic sequence of the SARS-CoV strain that was involved in the Amoy Gardens outbreak. These molecular epidemiological data help trace the evolution of the SARS-CoV in Hong Kong and provide the foundation for future studies attempting to correlate virus sequence variations with clinical features. The team also developed a plasma/serum RNA-based approach for SARS diagnosis. It is a real-time quantitative reverse transcriptase PCR-based system, which can detect SARS-CoV RNA in the plasma and serum in 80 per cent of SARS patients, as early as the first day of hospital admission. They observed that individuals with the more severe form of the disease have a median of 30 times higher circulating SARS-CoV RNA concentration than those who did not require I CU admission. They generated the first serial analysis data on plasma SARS-CoV RNA levels in a cohort of paediatric patients, and confirmed the relatively high sensitivity of this approach during the early stage of infection. This will have a significant impact on the early diagnosis and prognostication of the disease. 研究 Research 57