How worried should we be about the return of bird flu? - FT中文网
登录×
电子邮件/用户名
密码
记住我
请输入邮箱和密码进行绑定操作:
请输入手机号码,通过短信验证(目前仅支持中国大陆地区的手机号):
请您阅读我们的用户注册协议隐私权保护政策,点击下方按钮即视为您接受。
FT商学院

How worried should we be about the return of bird flu?

Now is not a time for paranoia but there is a case for extreme vigilance
00:00

{"text":[[{"start":null,"text":"

"}],[{"start":9.1,"text":"The writer is a science commentator "}],[{"start":12.2,"text":"In 2022, Bass Rock, a volcanic outcrop off the Scottish coast that houses the world’s largest colony of northern gannets, became a graveyard. "},{"start":21.029,"text":"Thousands of gannets were wiped out by a bird flu now thought to have killed millions of wild birds worldwide and devastated poultry flocks. "}],[{"start":28.58,"text":"Highly pathogenic avian influenza, or HPAI, became a zombie scourge that, unlike seasonal predecessors, never really disappeared. "},{"start":36.833999999999996,"text":"The virus that causes it, H5N1, has since jumped into species including mink, sea lions, dolphins, porpoises, otters and cats — and now cattle. "}],[{"start":47.98,"text":"As of Monday, nine US states had reported outbreaks in dairy cattle. "},{"start":52.583999999999996,"text":"One dairy worker in Texas has also tested positive. "},{"start":55.902,"text":"Viral fragments have been found in the country’s milk supply. "},{"start":59.093999999999994,"text":"Now, a US genomic analysis suggests a variant known as 2.3.4.4b has been spreading silently in cattle for months, perhaps since December. "}],[{"start":69.16,"text":"The virus does not usually pass from human to human but its undetected march into new mammalian hosts is not to be taken lightly, given that every infection offers the chance to mutate. "},{"start":78.514,"text":"The US Centers for Disease Control and Prevention says the risk to public health is low but it is preparing for the possibility that the flu becomes more transmissible between people. "},{"start":87.519,"text":"Now is not a time for paranoia but there is a case for extreme vigilance. "}],[{"start":92.52,"text":"Exactly how bird flu made the leap into cattle is unclear. "},{"start":96.17399999999999,"text":"Birds shed the virus orally, nasally and through their urine and faeces; cows could have ingested contaminated feed or water. "},{"start":103.029,"text":"Scientists believe the virus then spread between cows through mechanical methods, such as shared milking machines, rather than through the air. "},{"start":110.359,"text":"According to the UK government, this strain is not circulating in Europe. "}],[{"start":115.3,"text":"The World Health Organization has expressed “great concern” and advised caution. "},{"start":119.767,"text":"Paul Digard, an influenza virologist at the Roslin Institute, Edinburgh University, told me this week that the threat level had risen: “Firstly, cow infections with avian flu on this scale is something new; what else has the virus ‘learnt’ to do with this latest round of genetic changes? "},{"start":134.847,"text":"Secondly, infecting dairy cows offers more opportunities to infect humans. ”"}],[{"start":140.34,"text":"The US Food and Drug Administration advises against consuming raw (unpasteurised) milk products, to guard against pathogens such as salmonella and E-coli; H5N1 is now also on the list. "},{"start":152.05700000000002,"text":"The odds of becoming infected by drinking pasteurised milk is deemed very low, given that testing so far shows no live infectious virus in the samples. "}],[{"start":161.3,"text":"However, the presence of virus fragments in pasteurised milk points to the possibility of asymptomatic infected cows, meaning the virus could be spreading under the radar. "},{"start":170.842,"text":"The US Department of Agriculture, which has banned infected cattle from crossing state borders, has been urged to scale up testing. "}],[{"start":178.71,"text":"The infected dairy worker had conjunctivitis rather than respiratory symptoms; avian flu viruses struggle to latch on effectively to receptors in the human upper respiratory tract. "},{"start":188.464,"text":"But if the virus can get in, perhaps through high doses, it can be lethal: since 1997, H5N1 has killed about half of the roughly 900 people infected with it. "}],[{"start":199.72,"text":"One concern is “reassortment”: when two flu viruses circulating in the same infected animal swap genetic material. "},{"start":206.262,"text":"“H5N1 in pigs would be a very large, exceedingly red flag”, Digard warns, “given the frequency with which humans and pigs have exchanged [flu] viruses over the last 100 years. ”"},{"start":217.429,"text":"The respiratory tracts of pigs show similarities to ours, meaning that a swine-adapted flu virus might not require many changes to threaten us. "}],[{"start":226.3,"text":"The world is reasonably adept at dealing with seasonal flu, with global surveillance and an infrastructure for producing seasonal flu vaccines matched to circulating strains. "},{"start":235.429,"text":"There are also antivirals. "},{"start":237.27200000000002,"text":"But pandemic flu, especially caused by an animal virus to which humans have zero immunity, is a different prospect. "}],[{"start":245.03,"text":"There are existing, pre-authorised pandemic preparedness vaccines that can be adapted in a hurry, including ones from GSK and AstraZeneca targeting H5N1. "},{"start":254.572,"text":"Once the exact pandemic strain is identified, it can be included for production and further approval. "}],[{"start":260.52,"text":"Interestingly, the CDC has now shared the candidate vaccine virus 2.3.4.4b with manufacturers. "},{"start":268.087,"text":"How quickly things can move from here is another question — one that deserves an answer sooner rather than later. "}],[{"start":273.56,"text":""}]],"url":"https://creatives.ftacademy.cn/album/152811-1714571866.mp3"}

版权声明:本文版权归FT中文网所有,未经允许任何单位或个人不得转载,复制或以任何其他方式使用本文全部或部分,侵权必究。

乌克兰无人机袭击致索契俄罗斯油库起火

弗拉基米尔•泽连斯基对黑海设施遭远程打击表示欢迎,目前无人机和导弹的交火仍在持续。

我们不能把全球贸易的所有混乱都归咎于特朗普

世界贸易组织的许多体制和程序已经失灵,我们应当承认这一失败。

欧佩克+将石油产量配额上调至两年来最高水平

分析师预测,在该卡特尔取消减产后,原油将在今年年底前出现供应过剩。

中国出口会继续无视特朗普的贸易战吗?

我们可以预期英格兰银行利率制定者会释放哪些信号?美股还能继续上涨吗?

星巴克在曼哈顿对决中国的瑞幸咖啡

美国连锁店通过升级门店,并为顾客提供不同的服务方式,以提振销售。

澳大利亚偏远港口卷入美中安全博弈

澳大利亚总理安东尼•阿尔巴内塞因安全担忧誓言要收回达尔文港的控制权。
设置字号×
最小
较小
默认
较大
最大
分享×