SARS十年Shaken by SARS, Hong Kong Keeps Wary Eye on New Virus

SARS十年，新型病毒又來襲

KEITH BRADSHER 報道 2013年03月29日

香港——十年前，嚴重急性呼吸綜合征(SARS)橫掃了香港，隨後擴散到全球。現在，香港是首先擔心中東的另一種遺傳上相關病毒的出現和傳播的城市之一。
醫學研究者強調，他們不知道這種新病毒是否能產生與SARS病毒一樣的、在人與人之間傳播的能力。世界衛生組織（World Health Organization，簡稱WHO）正在採取一種謹慎的立場。

WHO周二宣布，迄今為止，被這種名為冠狀病毒的新病毒感染的17人中，已有11人死亡，其中包括一名英國男子，他去沙特阿拉伯和巴基斯坦旅行後生病。世衛組織要求各成員國政府報告所有的新病例，但尚未敦促採取任何特殊措施。
該組織說，“WHO不建議針對此事件在入境口岸進行特別篩查，也不建議採取任何旅行或貿易限制措施。”
但是，香港已開始採取預防措施。雖然到目前為止，東亞還沒有出現一位被確診感染病毒的人，但中國這個特區的政府已開始通知和培訓醫院、診所及機場的工作人員，以識別可能的病例。廣泛的醫療研究也已經開始。
特區政府高級官員周三舉行了大規模演習，模擬如果一位感染者到達機場，開始在香港傳播這種新病毒的話，政府將如何管理針對病人及有關人員的隔離和治療。香港衛生署稱，將”保持警惕，並繼續與WHO及其他海外衛生機構密切合作，以監測這種新傳染病的最新發展”。
美國還沒有任何病例的記錄。在歐洲，除了英國那起死亡病例，一名73歲男子於周二在德國死亡，他在一周前被從阿拉伯聯合酋長國醫療撤離。
香港政府的做法反映了一種對公共健康問題的持續關注，也有人稱之為過分擔憂。2003年春，香港在幾周內就有近1800人被SARS病毒感染出現嚴重癥狀，其中299人死亡。
香港大學(Hong Kong University)微生物系傳染病學分系主任袁國勇(Yuen Kwok-yung)說，“此刻，由於明顯的歷史原因，我認為香港有可能將是針對這種新病毒採取最嚴格邊境控制的政府。”
西方一些衛生專家對過分關注這種新病毒持謹慎態度。這種病毒跟SARS一樣，是一種冠狀病毒。他們指出，在SARS病毒爆發之後，由於研究者們開始下更大的工夫尋找冠狀病毒，他們找到的也越來越多。
很多這類研究在香港進行。在1997年香港回歸之前，這個英國的殖民地就已經成為了一個領先的疾病研究中心。導致黑死病的細菌是於1894年在香港 發現的。WHO也一直把亞洲各地的樣本送到香港大學檢查。袁國勇及其港大同事，在2003年發現SARS病毒、以及將其遺傳相似性追溯到一種感染野生蝙蝠 的病毒的研究中，起了關鍵作用。
如今，香港大學的研究者對中東出現的這種新病毒表示越來越多的擔憂。該病毒被命名為新型冠狀病毒EMC。SARS病毒發現者之一、香港大學流感研究 中心主任裴偉士(Malik Peiris)周二在一次講話中警告說，SARS病毒曾在全球感染了8445人，其中有790人死亡，儘管該病毒在一年後消失了，但在過去的兩個世紀里， 有其他兩種冠狀病毒已從在動物身上傳播轉移到在人身上傳播，成為地方性傳染病。
那兩種冠狀病毒僅僅導致普通感冒。對這種新型病毒的擔心之一是，它似乎更為致命，已造成確診病例中一半以上的死亡。袁國勇及其香港和大陸的12名同 事本周在《傳染病雜誌》(Journal of Infectious Diseases)發表的一項研究中發現，新病毒也比SARS病毒能感染更多的人體組織類型，更快地致這些組織死亡。
新病毒還能感染來自多種動物的細胞，包括猴子、兔子和豬。這使得新病毒有更多機會演化出對人的更大傳染性。這種病毒與在亞洲和歐洲的野生蝙蝠身上發現的病毒似乎在遺傳上接近，但並不完全相同。
一個大問題是，是否有更多的人被感染，但沒有被發現。如果是這樣的話，這種病毒導致的死亡百分比也許要低，但傳染性更大。袁國勇說，最近在沙特篩查了2400人，看他們是否有該病毒的抗體，結果是沒有一個人有抗體。
他說，這表明該病毒寄居在某種尚不確定的動物身上，偶爾感染人類，但還不具有在人與人之間傳染的能力。但是，那名到沙特和巴基斯坦旅行而感染該病毒的英國男子，在死前傳染了他家中的兩位成員。
16年來，H5N1禽流感病毒偶爾從鳥類傳播到人身上，並零星地導致患者死亡，卻一直沒有演化出在人與人之間持續傳播的能力。然而，SARS病毒2002年末在中國南部零星感染了一些人之後，僅在幾個月內，似乎就演化出了在人與人之間傳播的能力。
袁國勇說，至於這種新病毒，“我們面對的可能是2002年的情況，那會非常非常糟糕。但也可能是類似H5N1的情況。”

翻譯：梁英

Shaken by SARS, Hong Kong Keeps Wary Eye on New Virus

By KEITH BRADSHER March 29, 2013

HONG KONG — A decade after severe acute respiratory syndrome swept through Hong Kong and then around the world, the city is among the first to become worried about the emergence and spread of another, genetically related virus in the Middle East.
Medical researchers emphasize that they do not know if the new virus will develop the same ability as SARS to spread from person to person. The World Health Organization is taking a cautious stance.

The W.H.O. announced Tuesday that the virus, known as a coronavirus, had killed 11 of the 17 people infected so far, including a man in Britain who fell ill after traveling to Saudi Arabia and Pakistan. The health organization asked member governments to report any new cases, but stopped short of urging any special measures.
‘‘W.H.O. does not advise special screening at points of entry with regard to this event, nor does it recommend that any travel or trade restrictions be applied,” the agency said.
But Hong Kong is already taking preventive measures. Without a single confirmed human case of the new virus in East Asia so far, the government of the autonomous Chinese territory has already begun alerting and training employees at hospitals, clinics and the airport to identify possible cases. Wide-ranging medical research is already under way.
Senior government officials held an extensive exercise on Wednesday to simulate the oversight of the quarantine and treatment of patients and their associates if a single person infected with the new virus arrived at the Hong Kong airport and began spreading it. The Health Department announced that it would ‘‘stay vigilant and continue to work closely with the W.H.O. and other overseas health authorities to monitor the latest development of this novel infectious disease.”
No cases have been documented in the United States. In Europe, in addition to the death in Britain, a 73-year-old man died in Germany on Tuesday after being evacuated from the United Arab Emirates a week earlier.
The Hong Kong government’s measures reflect a continued preoccupation with public health — some say an obsession — after nearly 1,800 people in Hong Kong became extremely ill with SARS in a few weeks during the spring of 2003, with 299 of them dying.
‘‘At the moment, I think Hong Kong is likely to be the one with the strongest border control against this new virus for obvious historical reasons,’’ said Dr. Yuen Kwok-yung, chairman of the infectious-diseases section of the microbiology department at Hong Kong University.
Some health experts in the West have been wary of drawing too much attention to the new virus, which is a so-called coronavirus like SARS. They point out that as researchers have begun looking harder for coronaviruses after the SARS outbreak, they have found more of them.
Much of the research has been done in Hong Kong, which became a leading center for disease research as a British colony before the handover to China in 1997; the bacteria that causes bubonic plague was discovered in Hong Kong in 1894. The W.H.O. has long sent samples from all over Asia to Hong Kong University for testing, and Dr. Yuen and his colleagues at the university played a central role in identifying the SARS virus in 2003 and then tracing its genetic similarities to a virus that infects wild bats.
Hong Kong University researchers are now expressing growing concern about the new coronavirus that has emerged in the Middle East, dubbed novel coronavirus EMC. Dr. Malik Peiris, a co-discoverer of SARS who is the director of the center for influenza research at Hong Kong University, warned in a speech on Tuesday that while SARS faded away after a year, with 8,445 cases and 790 deaths worldwide, two other coronaviruses had jumped from animals to people in the past two centuries and become endemic.
Both of those coronaviruses merely cause common colds. One of the concerns about the novel coronavirus is that it seems deadlier, having killed more than half of the people with confirmed cases. A study published this week in the Journal of Infectious Diseases by Dr. Yuen and 12 colleagues in Hong Kong and mainland China found that the new virus also infects a wider range of human tissue types than the SARS virus and kills them more quickly.
The new virus also infects cells from a range of animals, including monkeys, rabbits and pigs, which could offer further opportunities for the new virus to develop greater transmissibility in people. The virus appears genetically close but not identical to viruses found in wild bats in Asia and in Europe.
One big question is whether far more people are being infected without detection, in which case the disease may kill a lower percentage of victims but also be more transmissible. Dr. Yuen said that when 2,400 people were screened recently in Saudi Arabia for antibodies to the virus, none had them.
That suggests that the virus is periodically infecting people from an unknown animal host, but has not developed the ability to pass easily from person to person, he said. However, the man in Britain who fell ill with the virus after traveling to Saudi Arabia and Pakistan infected two members of his household in Britain before he died of the disease.
The H5N1 avian influenza virus has been periodically jumping from birds to people and causing sporadic deaths for 16 years without developing sustained transmissibility among people. On the other hand, the SARS virus appears to have developed transmissibility after only a few months of sporadic infections of people in southern China in late 2002.
For the new virus, ‘‘we may be at the 2002 situation at this time, and that would be very, very bad,’’ Dr. Yuen said. “But this also may be like H5N1. “