US News 5月13日文章Did the Coronavirus Originate Outside of Wuhan?
冠状病毒是否起源于武汉以外地区？
Research by a Cambridge geneticist suggests the coronavirus may have been circulating earlier than previously believed.
剑桥遗传学家的研究表明，冠状病毒的传播时间可能比以前认为的要早。
LONDON – THERE'S NOdoubt that the novel coronavirus that causes COVID-19, the highly contagious disease that's so far infected more than 4.2 million people globally and killed nearly 290,000, originated in China.
伦敦-毫无疑问，导致COVID-19的新型冠状病毒起源于中国，该病毒是一种高度传染性疾病，迄今为止已感染全球超过420万人并杀死了近290,000人。
But while early analyses of the outbreak indicated that it first emerged in humans in the city of Wuhan — which became the epicenter of China's epidemic — possibly at a seafood market, that scenario hasn't been fully confirmed by researchers.
但是，尽管对该疾病的早期分析表明，该病首次在人类中出现是在武汉市（该市已成为中国流行病的中心），可能在一个海鲜市场上出现，但这种情况尚未得到研究人员的充分证实。
Now a University of Cambridge geneticist says there is strong circumstantial evidence that the virus didn't originate in Wuhan after all.
现在，剑桥大学的遗传学家说，有很强的间接证据表明这种病毒不是起源于武汉。
"This idea that the Wuhan seafood market is the origin is actually not clear-cut," says Peter Forster, a fellow in archaeological research at Cambridge.
剑桥考古研究研究员彼得·福斯特（Peter Forster）说：“关于武汉海鲜市场是起源的说法实际上还不明确。”
If Forster's research holds up, it would also put to rest a dubious claim made by U.S. President Donald Trump and Mike Pompeo, the secretary of state, that the pathogen leaked from the Wuhan Institute of Virology, a government lab. Neither Trump nor Pompeo has offered evidence to back up that assertion, and the intelligence agencies of America's closest allies have debunked it.
如果Forster的研究坚持下去，它还将击溃美国总统唐纳德·特朗普和国务卿迈克·庞培的可疑说法，即该病原体是从武汉政府实验室病毒研究所泄漏的。特朗普和庞培都没有提供证据来支持这一主张，而美国最亲密盟友的情报机构也对它进行了揭穿。
Forster is a co-inventor of phylogenetic algorithms that have, since the 1990s, become the standard software for mining genetic data to reconstruct human evolutionary trees, or networks. His team applied the software to 44 genome samples of the coronavirus gleaned from the earliest official reported cases in China from Dec. 24 of last year to Jan. 17.
Forster是系统进化算法的共同发明者，自1990年代以来，它已成为挖掘遗传数据以重建人类进化树或网络的标准软件。他的团队将该软件应用于从去年12月24日至1月17日在中国最早公布的官方病例中收集到的44个冠状病毒基因组样本中。
In a recent paper published in the journal Proceedings of the National Academy of Sciences, Forster reported he found three main strains of the virus that he labeled A, B and C.
在最近发表在《美国国家科学院院刊》上的一篇论文中，福斯特（Forster）报告他发现了三种主要的病毒株，并分别标记了A，B和C.
His research determined that A was the founding variant because it was the version most similar to the type of SARS-Cov-2 (the scientific name for the virus) discovered in bats. Many experts suspect that the virus migrated to humans from bats, probably via some other animal. But he also discovered that the A strain wasn't the predominant type in Wuhan.
他的研究确定A是创始变体，因为它是与蝙蝠中发现的SARS-Cov-2（病毒的科学名称）类型最相似的版本。许多专家怀疑这种病毒可能是通过其他动物从蝙蝠迁移到人类的。但他还发现，A株不是武汉市的主要类型。
Of 23 samples that came from Wuhan, only three were type A, the rest were type B, a version two mutations from A. But in other parts of China, Forster says, initially A was the predominant strain. For instance, of nine genome samples in Guangdong, some 600 miles south of Wuhan, five were A types.
在来自武汉的23个样本中，只有3个是A型，其余的是B型，这是A的两个突变。但福斯特说，在中国的其他地区，最初A是主要菌株。例如，在武汉市以南约600英里处的广东省的9个基因组样本中，有5个是A型。
"I would be a bit careful about pinpointing a place (of origin), because we don't have many samples from the early phase," he says. "But it seems to me we shouldn't restrict ourselves to Wuhan when looking for the origin."
他说：“在确定一个（来源地）地方时，我会比较谨慎，因为我们没有很多来自早期的样本。”“但是在我看来，寻找来源时我们不应该局限于武汉。”
Asked if his ongoing research should quash speculation that the virus leaked from the Wuhan lab, Forster is circumspect. "It's not black and white. All I can say is it doesn't look to me as if Wuhan is the prime candidate, because A exists in other regions of China at that time at possibly a higher frequency."
当被问及他正在进行的研究是否应该阻止人们猜测该病毒从武汉实验室泄漏时，福斯特对此持谨慎态度。 “这不是黑白的。我只能说武汉似乎不是主要的候选人，因为那时A在中国其他地区的出现频率可能更高。”
The B type has since become the predominant version. The A type has largely petered out, as has the third variant, C, which mainly took hold in Singapore, South Korea, Hong Kong and in scattered areas around Europe.
此后，B型成为主要版本。 A型和第三型C基本上消失了，C型主要在新加坡，韩国，香港和欧洲各地分布。
Forster's research also indicates that COVID-19 may have been circulating among humans and animals before the reported first case in China on Dec. 1. The mutation rate he used indicates that there is a 95% chance that the original successful spread of the virus may have commenced as far back as Sept. 13, 2019.
Forster的研究还表明，在12月1日中国首次报告病例之前，COVID-19可能已经在人与动物之间传播。他使用的突变率表明，有95％的可能性该病毒的成功传播最早可以追溯到2019年9月13日。
However, he adds, that assumes "that the mutation rate is constant and that I can simply use it as a clock to go back in time." Since then, however, he's now analyzed 1,001 virus genomes, and has determined that while the mutation rate in East Asia is around 1.5 per month, outside that region it's closer to 2 or 2.1 per month.
但是，他补充说，这是假设“突变率是恒定的，我可以简单地将其用作返回时间的时钟”。但是从那以后，他分析了1,001个病毒基因组，并确定，尽管东亚的突变率每月约为1.5，但在该区域以外的突变率则接近每月2或2.1。
"It's clear that the virus can change its mutation rate," Forster explains. "And if that has happened now, it might also have happened in the past, and in that case we can't be sure whether my estimate is accurate. But I would say it's the best we can do at the moment."
Forster解释说：“很明显，病毒可以改变其突变率。” “如果现在发生这种情况，那么它可能也曾经发生在过去，在那种情况下，我们不能确定我的估计是否准确。但是我想这是目前我们唯一能做的事情。”
The B type's rapid mutation rate also doesn't look like neutral evolution, he says, and it may be affected by some form of natural selection in response to environmental influences. "The virus seems to have accelerated outside East Asia, and this is in keeping with the odd appearance of the B type."
他说，B型的快速突变率也不像是中性进化，它可能受到某种形式的自然选择以此来响应环境的影响。 “这种病毒似乎在东亚以外地区已经加速传播，这与B型怪异的外观保持一致。”
That finding also seems to be in line with research last week out of the Los Alamos National Laboratory that found that the current dominant strain of the coronavirus appears to be more contagious than other strains.
这一发现似乎也与上周在洛斯阿拉莫斯国家实验室进行的研究相一致，该研究发现，目前冠状病毒的优势株似乎比其他株更具传染性。
Ian Lipkin, a virologist at Columbia University, is working with Chinese researchers to investigate hospital samples in China to see if there is more evidence that the outbreak occurred elsewhere in China before it was picked up in Wuhan. "He is conducting the kind of work my research is pointing at," Forster says.
哥伦比亚大学的病毒学家伊恩·利普金（Ian Lipkin）正在与中国研究人员合作，调查中国的医院样本，以查看是否有更多证据表明该疫情是在武汉其他地方之前发生的。Forster 说：“他正在开展我的研究所开展的工作。”
Determining the exact origins of a lethal virus is an important step in trying to stop future outbreaks of similar pathogens, which is why Lipkin and virologists -- some guided by roadmaps like Forster's genetic family trees -- are making a concerted effort to pinpoint COVID-19's origins. And chances are good that they'll eventually solve the mystery.
确定致死病毒的确切来源是试图阻止未来爆发类似病原体的重要一步，这就是为什么利普金和病毒学家（在某些路线图的指导下，例如Forster的遗传家谱）正在共同努力查明COVID- 19的起源。并且他们最终解决这个谜团的可能性是很大的。
原文链接：https://www.usnews.com/news/best-countries/articles/2020-05-13/scientist-suggests-coronavirus-originated-outside-of-wuhan
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