新型冠狀病毒與SARS經驗回顧

A Novel Coronavirus and a Review of the Severe Acute Respiratory Syndrome Experience

2012年9月23日，世界衛生組織公布了兩名來自中東的病人感染一種新型的冠狀病毒，其中一例已死亡，另一例則需暫時使用葉克膜（ECMO）來維持生命，兩者臨床表現同時出現急性呼吸道感染合併急性腎功能衰竭，荷蘭的實驗室首先從第一例病人的痰液檢體中檢出一種新型的冠狀病毒，並命名為HCoV- EMC/2012，而隨後第二例病人也在英國住院期間於其痰液檢體中檢出相同病毒，此病毒在病毒學分類上與第二型（又稱ß冠狀病毒）b群的人類SARS（severe acute respiratory syndrome）冠狀病毒並不相同，反而和另外兩種蝙蝠身上的冠狀病毒BtCoV-HKU4及BtCoV-HKU5較為相似，併同屬於第二型（ß冠狀病毒）c群。世界衛生組織同時在同年11月底又再度公布了7個新病例，當時已累積達9例，其中5個病患已死亡，這些病人均來自中東地區，並且有兩次小規模的群聚事件發生。SARS病毒在2003年曾造成全世界的大流行，後來研究證實主要是由果子狸的SARS冠狀病毒跨越物種傳染給人類所造成，但在2003年大流行後，隨著大家提高生物安全警覺及加強院內感染管制品質，SARS病毒似乎已從人類的世界消失；目前大家對此次新分離出的新型冠狀病毒HCoV-EMC仍不甚了解，但即使在此階段此病毒尚未具有高度傳染力，吾輩仍需提高警覺並小心防範，特別加強疑似病人之旅遊史、職業史、接觸史及群聚史的問診，並做好一切必要之感控措施，避免另一個類似SARS的大流行再度發生。

On September 23, 2012, the World Health Organization (WHO) announced that 2 patients from the Middle East were infected with a novel coronavirus. One patient was dead, and the other patient needed the temporary use of extracorporeal membrane oxygenation to sustain his life. Both cases had similar clinical presentations: acute respiratory syndrome with acute renal failure. A laboratory in the Netherlands was the first to isolate the novel coronavirus, HCoV-EMC/2012, from the first patient’s sputum specimen. Subsequently, the second patient, while hospitalized in the United Kingdom, also had the same virus detected in a lower respiratory tract sample. This virus was later classified as a group 2c betacoronavirus, which is genetically quite distinct from the group 2b human severe acute respiratory syndrome (SARS) betacoronavirus; nonetheless, this particular virus is phylogenetically related to the bat coronaviruses HKU4 and HKU5. By the end of November 2012, the WHO announced 7 new cases of the novel coronavirus, amounting to a total of 9 cases being reported up until then, including 5 that resulted in death. All of these patients were from the Middle East. Moreover, 2 small-scale clustering events raised the possibility of limited human-to-human viral transmission. The SARS virus caused a worldwide pandemic in 2003, and subsequent studies confirmed that its transmission was caused by interspecies jumping of the SARS coronavirus from civets to humans. However, after the 2003 pandemic, with improved vigilance in biosecurity and strengthened nosocomial infection control quality, the SARS virus seemed to disappear globally. The newly isolated coronavirus, HCoV-EMC, is still not well understood, and its route of transmission is unknown. At this stage, we should remain vigilant; take precautions; enhance travel awareness; maintain a record of the occupation and contact and cluster history for suspected patients; and take all necessary infection control measures to avoid another SARS-like pandemic.