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cover of episode How Bird Flu Went from an Isolated Avian Illness to a Human Pandemic Threat (Part 1)

How Bird Flu Went from an Isolated Avian Illness to a Human Pandemic Threat (Part 1)

2025/6/23
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Science Quickly

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K
Keiji Fukuda
L
Larry Niles
L
Lisa Kircher
L
Louise Moncla
N
Nancy Cox
P
Pamela McKenzie
R
Robert Webster
W
Wendy Puryear
Topics
Pamela McKenzie: 作为一名病毒侦探,我主要负责在特拉华湾监测迁徙涉禽中流行的禽流感病毒。特拉华湾是禽流感病毒的热点地区,每年都有不同的流感病毒在这里被发现。我们团队在特拉华湾收集的粪便样本中几乎检测到了所有禽流感亚型,包括H5N1。虽然在特拉华湾停靠的滨鸟可能没有携带对家畜或人类危险的禽流感,但通过基因混合,我们可能会看到新的致命毒株爆发。 Robert Webster: 我从1985年开始在特拉华湾进行圣裘德的流感监测研究,至今已持续40年。圣裘德实验室的重要贡献是发现水禽体内的流感病毒主要在肠道内复制,然后通过粪便排出。因此,通过在特拉华湾跟随鸟类并从海滩上收集它们的粪便样本,我们无需捕捉鸟类就能研究病毒。我还帮助鉴定了香港爆发的H5N1病毒,当时没有人相信H5N1病毒会导致儿童死亡。 Keiji Fukuda: 过去我们认为动物流感病毒和人类流感病毒是不同的,动物流感病毒不会感染人类。在1997年香港爆发的H5N1疫情中,我们发现这种病毒能够感染人类,这彻底改变了我们的认知。当时我们非常担心这次的病毒是否会变成另一次大流行。 Nancy Cox: 我们没想到高致病性禽流感病毒会感染人类。自1997年香港爆发以来,H5N1病毒已在全球传播,并呈现出巨大的多样性,这意味着病毒有更多机会发展出更有效地感染人类的能力,并最终可能实现人际传播。 Wendy Puryear: H5N1病毒的突变正在创造出能够更好地感染不同动物的毒株,这让我越来越不安。在COVID-19大流行之前,我们最担心的是下一次对人类健康产生重大影响的流感大流行。H5N1病毒不断达到令人不安的突变里程碑。H5N1病毒已在各大洲的动物中被检测到,并在亚洲、中东、美洲、非洲和欧洲的家禽中扎根。携带H5N1病毒的鸟类物种数量激增,从2020年到2021年左右,高致病性H5N1开始感染不同的哺乳动物。2022年和2023年,病毒在秘鲁和智利沿海的各种海洋动物中传播,导致超过30,000只海狮死亡,并蔓延到大西洋沿岸。 Louise Moncla: 北美洲的低致病性病毒与新病毒混合,导致了新的基因型的出现。不同的流感病毒在同一宿主内共同感染时,会发生基因混合或重组。基因重组是流感进化的一个非常重要的过程,因为它导致了我们所知的每一次大流行。当来自两个不同物种的病毒通过重组混合,并产生一种宿主群体(如人类)没有任何先前免疫力的病毒时,通常会发生流感大流行。候鸟和野生动物不应为H5N1的传播负责,人类的监测和应对方式才是关键。我们需要更好地了解这些病毒在野生鸟类中是如何进化的,持续监测野生鸟类至关重要。 Lisa Kircher: 我在圣裘德儿童研究医院的Webby实验室担任实验室运营主管,我们的实验室是一个大型流感研究实验室。我住在卡车和露营车里,与储存在冷液氮中的粪便样本一起生活和睡觉。实时监测可以更快地进行风险评估。为了更全面地了解流感,需要更多的数据。要确定粪便来自哪种鸟类,需要更多的测试和时间。病毒在迁徙路线上跳入哺乳动物体内,有机会突变成更像哺乳动物的病毒。移动实验室可以扩展成一个大型生物监测网络。如果农民可以访问一个仪表板,了解流感病毒的传播情况,并提前加强生物安全措施,那就太好了。监测鸟类留下的线索,可以更快地发现病毒的突变,从而更好地应对。 Larry Niles: 我不是病毒学家,而是一名生态学家,但我了解事物的生态学,我认为将鸟类的生态学与病毒的生态学相结合,共同找出答案。

Deep Dive

Shownotes Transcript

Bird flu outbreaks in poultry and cattle have caused concern for public health officials. There have been few reported cases of human transmission, but the growing risks of H5N1 avian influenza have virologists on alert.

Researchers at the St. Jude Center of Excellence for Influenza Research and Response take an annual visit to Delaware Bay to collect samples of bird poop for analysis. These samples give the researchers a look at emerging avian illnesses. While spillover of H5N1 into domestic birds has been known for a while, the first case of spillover into humans was only identified during a 1997 outbreak in Hong Kong. Since then H5N1 has gone global and moved from transmitting from bird to bird to spreading from bird to mammal and from mammal to mammal.

Associate health and medicine editor Lauren Young takes a sample collection walk on the beach and speaks with virus detectives about how H5N1 evolved in episode one of our three-part series about bird flu.

Join us on Wednesday to learn how bird flu jumped from poultry to cattle.

Recommended reading:

RFK, Jr., Wants to Let Bird Flu Spread on Poultry Farms. Why Experts Are Concerned https://www.scientificamerican.com/article/rfk-jr-wants-to-let-bird-flu-spread-on-poultry-farms-why-experts-are/

Bird Flu Detected in Humans in the U.S.: What We Know So Far https://www.scientificamerican.com/article/bird-flu-detected-in-a-person-in-texas-what-we-know-so-far/

E-mail us at [email protected]) if you have any questions, comments or ideas for stories we should cover!

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Science Quickly is produced by Rachel Feltman, Fonda Mwangi, Kelso Harper, Naeem Amarsy and Jeff DelViscio. This episode was hosted by Rachel Feltman with guest Lauren Young. This series was reported and produced by Lauren Young, Meghan Bartels, Naeem Amarsy, Fonda Mwangi and Jeff DelViscio. And special thanks to Kimberly Lau and Dean Visser at Scientific American for making it possible and to Michael Sheffield at St. Jude for assistance in the field. Our show is edited by Alex Sugiura with fact-checking by Shayna Posses and Aaron Shattuck. The theme music was composed by Dominic Smith.

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