英国新冠疫情或存在1300多个不同源头
英国一家机构的研究表明，英国的疫情并非由单一一位“零号病人”引起，而是存在至少1300个不同的源头。研究还发现，英国最初的新冠肺炎病例大多来自欧洲国家，直接来自中国的不到0.1%。
Coronavirus was brought into the UK on at least 1,300 separate occasions, a major analysis of the genetics of the virus shows.
一项对新冠病毒基因的大型分析显示，新冠病毒至少由1300个不同的源头传入英国。
The study, by the Covid-19 Genomics UK consortium (Cog-UK), completely quashes the idea that a single “patient zero” started the whole UK outbreak.
由新冠英国基因组学联盟进行的这项研究，彻底推翻了单一“零号病人”引发英国全部疫情的观点。
The analysis also finds China had a negligible impact on cases in the UK.
分析还发现，中国对英国病例的影响微不足道。
Instead those initial cases came mostly from European countries.
相反，英国最初的病例大多来自欧洲国家。
The researchers analysed the genetic code of viral samples taken from more than 20,000 people infected with coronavirus in the UK.
研究人员分析了英国两万多名新冠病毒感染者的病毒样本的基因码。
Then, like a gigantic version of a paternity test, the geneticists attempted to piece together the virus’s massive family tree.
然后，就像一个巨大版本的亲子鉴定一样，遗传学家试图拼凑出病毒庞大的族谱。
This was combined with data on international travel to get to the origins of the UK epidemic.
这一数据与国际旅行数据相结合，得出了英国疫情的起源。
They found the UK’s coronavirus epidemic did not have one origin - but at least 1,356 origins. On each of those occasions somebody brought the infection into the UK from abroad and the virus began to spread as a result.
他们发现，英国的新冠疫情不只有一个源头，而是至少有1356个源头。每次有境外输入病例时，就会把病毒从国外带到英国，之后病毒开始传播。
“The surprising and exciting conclusion is that we found the UK epidemic has resulted from a very large number of separate importations,” said Prof Nick Loman, from Cog-UK and the University of Birmingham.
来自该机构和伯明翰大学的尼克·洛曼教授说：“令人惊讶和兴奋的结论是，我们发现英国的疫情是由大量单独的外国输入病例造成的。”
“It wasn’t a patient zero,” he added.
“而不是由一位‘零号病人’引发”，他补充说。
The study showed that less than 0.1% of those imported cases came directly from China. Instead the UK's coronavirus epidemic was largely initiated by travel from Italy in late February, Spain in early-to-mid-March and then France in mid-to-late-March.
研究显示，这些输入病例中，直接来自中国的不到0.1%。相反，英国新冠疫情主要是由2月下旬从意大利出发、3月上旬至中旬从西班牙出发、3月中下旬从法国出发前来英国的国际旅行者引发的。
“The big surprise for us was how fluid the process was, the rate of and source of virus introduction shifted rapidly over the course of only a few weeks,” said Prof Oliver Pybus, from the University of Oxford.
牛津大学的奥立弗·皮布斯教授说：“最让我们吃惊的是这个过程是多么的流畅，病毒传播的速度和来源在短短几周内就迅速发生了变化。”
“This happened later than perhaps we would have expected,” added Prof Loman.
洛曼教授补充道：“这可能比我们预期的要晚。”
The study estimates 80% of those initial cases arrived in the country between 28 Feb and 29 March - the time the UK was debating whether to lockdown.
该研究估计，80%的最初病例是在2月28日至3月29日期间抵达英国的，当时英国正在讨论是否实施封锁。
After this point, the number of new imported cases diminished rapidly.
此后，新增输入病例迅速减少。
The earliest one could be traced back to the beginning of February, but it is possible there were cases even earlier that could not be picked up by the analysis.
最早的病例可以追溯到2月初，但也有可能还有更早的病例无法通过分析发现。
The study also says the controversial football match between Liverpool and Atletico Madrid, on 11 March, probably had very little impact on bringing the virus into the country.
研究还指出，3月11日利物浦队和马德里竞技队之间那场有争议的足球比赛可能对将病毒带入英国的影响很小。
An estimated 3,000 fans flew in from Spain to watch the game, but there were 20,000 people flying in from Spain every single day in mid-March.
据估计，有3000名球迷从西班牙乘飞机前来英国观看比赛，但在3月中旬，每天都有2万人从西班牙乘飞机前来英国。
“[It] shows that individual events such as football matches likely made a negligible contribution to the number of imports at that time,” the study says.
研究指出：“这表明，当时足球比赛等单项赛事对输入病例的影响可能微乎其微。”
The imported cases each started off a chain of transmission where the virus is passed from one person, to the next, to the next and so on.
每个输入病例都会开启一个传播链，病毒接连传播给一个又一个人。
However, the study shows lockdown has massively disrupted the spread of the virus.
然而研究表明，封锁措施极大地阻断了病毒的传播。
“If there’s good news here, these chains of transmission were and are being suppressed and going extinct as a result of social distancing and we continue to see that now,” Prof Loman said.
洛曼教授说：“如果有好消息的话，那就是，由于社交隔离的措施，这些传播链持续受到抑制，并而正在消失，而这种情况一直在持续。”
