Yeh Shiou-Hwei, Wang Hurng-Yi, Tsai Ching-Yi, Kao Chuan-Liang, Yang Jyh-Yuan, Liu Hwan-Wun, Su Ih-Jen, Tsai Shih-Feng, Chen Ding-Shinn, Chen Pei-Jer
Division of Molecular and Genomic Medicine, National Health Research Institutes, Taipei 115, Taiwan.
Proc Natl Acad Sci U S A. 2004 Feb 24;101(8):2542-7. doi: 10.1073/pnas.0307904100.
Since early March 2003, the severe acute respiratory syndrome (SARS) coronavirus (CoV) infection has claimed 346 cases and 37 deaths in Taiwan. The epidemic occurred in two stages. The first stage caused limited familial or hospital infections and lasted from early March to mid-April. All cases had clear contact histories, primarily from Guangdong or Hong Kong. The second stage resulted in a large outbreak in a municipal hospital, and quickly spread to northern and southern Taiwan from late April to mid-June. During this stage, there were some sporadic cases with untraceable contact histories. To investigate the origin and transmission route of SARS-CoV in Taiwan's epidemic, we conducted a systematic viral lineage study by sequencing the entire viral genome from ten SARS patients. SARS-CoV viruses isolated from Taiwan were found closely related to those from Guangdong and Hong Kong. In addition, all cases from the second stage belonged to the same lineage after the municipal hospital outbreak, including the patients without an apparent contact history. Analyses of these full-length sequences showed a positive selection occurring during SARS-CoV virus evolution. The mismatch distribution indicated that SARS viral genomes did not reach equilibrium and suggested a recent introduction of the viruses into human populations. The estimated genome mutation rate was approximately 0.1 per genome, demonstrating possibly one of the lowest rates among known RNA viruses.
自2003年3月初以来，严重急性呼吸综合征（SARS）冠状病毒（CoV）感染在台湾已导致346例病例和37人死亡。疫情分两个阶段发生。第一阶段导致有限的家庭或医院感染，从3月初持续到4月中旬。所有病例都有明确的接触史，主要来自广东或香港。第二阶段在一家市级医院引发了大规模疫情，并在4月下旬至6月中旬迅速蔓延至台湾北部和南部。在此阶段，有一些散发病例的接触史无法追踪。为了调查台湾疫情中SARS-CoV的起源和传播途径，我们通过对10例SARS患者的病毒全基因组进行测序，开展了一项系统的病毒谱系研究。发现从台湾分离出的SARS-CoV病毒与来自广东和香港的病毒密切相关。此外，市级医院疫情爆发后，第二阶段的所有病例都属于同一谱系，包括那些没有明显接触史的患者。对这些全长序列的分析表明，SARS-CoV病毒进化过程中发生了正向选择。错配分布表明SARS病毒基因组尚未达到平衡，提示这些病毒是近期传入人群的。估计的基因组突变率约为每基因组0.1，这可能是已知RNA病毒中最低的突变率之一。
