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內華達州的奶牛群感染了此前從未在牛身上出現的H5N1禽流感病毒,這一消息披露后引起病毒學家和研究人員高度警惕。而且內華達州農業部發布的消息顯示,想把該病毒從美國牛群中徹底清除,并不像聯邦官員之前宣稱或希望的那般容易。
2月7日又一個打擊接連而至,可能還更嚴重。美國農業部一份技術簡報稱,這種叫D1.1的基因型包含一種基因突變,或許會讓該病毒在包括人類在內的哺乳動物體內更容易復制。
而D1.1版本病毒,正是導致路易斯安那州一名男子死亡,加拿大一名青少年住院且病情危重的病毒變種。該病毒并非去年年初以來在患病牛群中常見的B3.13基因型。
“如果該病毒繼續在奶牛中傳播并感染更多人,可能引發深切關注,”免疫學家、前聯邦衛生官員里克?布萊特向《財富》雜志表示,“目前該突變尚未導致人際傳播加強,所以跡象無法證明其傳播性有所提升。不過比起在奶牛中傳播的(B3.13)病毒,這種病毒一旦感染人類引發的疾病很可能嚴重得多。”
“該病毒蔓延已迫在眉睫,”布萊特補充道,“為預防或降低病毒蔓延的沖擊,相關準備仍然不充分。”
D1.1基因型已在北美遷徙路線的野生鳥類以及哺乳動物和家禽中檢測到,因此傳播到奶牛身上不足為奇。但很多病毒學家認為,內華達州奶牛群中發現標志著H5N1傳播的拐點,意味著人類將面臨更多麻煩。
“D1.1對人類的毒性似乎更大,可能表明在公共衛生風險級別上與早期B3.13毒株相比出現了重大變化,”美國國立衛生研究院(National Institutes of Health)新發及人畜共患傳染病中心主任,也是獸醫學領域領軍人物于爾根?里希特向《財富》雜志表示。
針對一系列郵件提問,美國疾病控制和預防中心(CDC)發言人表示,該機構仍認為該病毒對普通公眾的健康風險很低。“不過,與受感染鳥類或其他動物(包括家畜),或者與受感染鳥類或其他動物污染所處環境有密切、長時間,或無防護措施接觸的人感染風險更高,”發言人表示。
2月7日美國農業部指出,在檢測之前內華達州奶牛并無臨床感染癥狀,但此后有報道稱奶牛已明顯發病,且奶牛場附近出現大批野生鳥類死亡。
人類是否應采取預防措施?風險程度如何?美國的農場和奶牛場是否已采取緩解措施?
種種問題的緊迫性表明,接下來幾周內必須高度重視及時發布聯邦機構的信息及檢測的最新情況,因為研究人員和衛生官員往往依賴相關信息。可惜,當前不能太過指望信息順暢流通。
1月21日,根據特朗普政府的命令,美國衛生與公眾服務部(HHS)凍結了幾乎所有的對外交流,包括文件和健康指導等,直到特朗普任命的官員到任并批準放行。此舉并非沒有先例,但信息凍結在2月1日的截止日期之后仍未完全解除,民主黨領導人開始表示不滿。
特朗普指令有個重大影響,即疾病控制與預防中心發布的《發病率與死亡率周報》(Morbidity and Mortality Weekly Report)受到沖擊。這份報告向來是公共衛生問題的重要信息來源。1 月 23 日,《發病率與死亡率周報》60多年來首次未能按時出版,1月30日再次停刊。2月6日雖恢復發行,《華盛頓郵報》(Washington Post)報道稱其中未提及禽流感,也沒有原定于1月發布的三項 H5N1 研究的信息。
此外據《華爾街日報》(Wall Street Journal)報道,特朗普政府計劃裁減美國衛生與公眾服務部數千名員工。報道稱,政府要求公共衛生高級官員根據員工的工作重要程度排名。
由于種種措施在衛生部門各機構的影響,禽流感追蹤和新藥批準等可能會受到影響。2023年,特朗普提名的衛生與公眾服務部負責人小羅伯特·F·肯尼迪表示,他將對聯邦衛生領域的科學家說,“感謝你們對公眾的服務。接下來八年左右,傳染病(研究)將暫停。”
事態發展導致追蹤H5N1傳播的科學家和研究人員越發擔憂。美國疾病控制與預防中心稱,H5N1現已感染美國959個奶牛群,導致1.56億只家禽死亡,供應短缺推動雞蛋價格創下歷史新高。
研究人員還強烈呼吁,應考慮是否使用聯邦儲備的禽流感疫苗為奶業工人接種,以及在奶牛場和蛋禽養殖場為一線工作人員強制配備個人防護裝備。
各種決策都有賴于信息及時流通和傳播,然而專家表示在這關鍵時刻信息溝通受限。
“想想2020年新冠疫情開始時科學家遭封口,科學傳播受到操縱,現在的情況令人寒心卻毫不奇怪,”疫苗研究員布萊特說,2020年他曾舉報投訴特朗普政府,幾個月來一直敦促衛生官員加強禽流感檢測和預防措施。
布萊特說,“2020年時,疫情應對速度放緩,公眾對科學和公共衛生產生不信任,結果是更多人喪生。令人痛心的是,人們并沒有吸取教訓,當前情況跟當時同樣糟糕乃至更差,不僅是在禽流感方面,美國對眾多其他事件的應對同樣有問題。”
內華達州一名官員向《財富》雜志透露,奶牛感染 D1.1 病毒的新病例追溯至丘吉爾縣的奶牛場,目前已有六個牛群被隔離。此前,內華達州農業局長 J?J?戈伊科切亞曾對路透社表示:“顯然,我們沒能做好充分準備,否則病毒也不會侵入。” 戈伊科切亞稱,內華達州的養殖戶應遵循 “良好的動物健康安全實踐,并加強生物安全措施”。
這一切對人類意味著什么?按照薩斯喀徹溫大學(University of Saskatchewan)病毒學家安吉拉·拉斯穆森的說法,內華達州的疫情并不會直接增加人傳人的可能性,只是“增加了動物傳人的風險,也就是從奶牛傳給農場工人”。除此之外,真正讓研究人員感到擔憂的是D1.1的突變能力(或許B3.13尚未出現類似突變)。其適應能力可能導致病毒更容易在人際傳播。
“在已知的少數人類感染病例中,H5N1病毒的新基因型D1.1會導致嚴重疾病甚至死亡,”布萊特說,“內華達州的病例意義重大,因為現在我們清楚地知道H5N1病毒在奶牛之間,以及從一個農場到另一個農場傳播多么容易。病毒不僅能從牛奶傳播到其他哺乳動物,比如老鼠和貓,還能感染人類。”
內布拉斯加大學(University of Nebraska)全球衛生安全中心主任詹姆斯·勞勒表示,近幾個月來,聯邦衛生機構采取了“一些積極措施”,通過全美牛奶檢測戰略增加檢測,還對人類進行流感檢測和亞型分析。
“為了更好地控制風險,我們應該加強受感染奶牛群和動物的檢測與隔離,推動更廣泛的人類監測和檢測,加快疫苗研發與生產。”勞勒說。布萊特還表示,臨床醫生需要知道病毒正在傳播,而且要“檢測流感,而不是靠猜。”
賓夕法尼亞大學(University of Pennsylvania)病毒免疫學家斯科特·亨斯利表示贊同,“我們要密切監測D1.1病毒,因為病毒已表現出適應能力,而且能引發人類罹患嚴重疾病。”亨斯利還提到,“現有的H5N1疫苗儲備與D1.1病毒匹配良好,有望提供高度防護。仍需加快H5N1疫苗生產,以防病毒演化到人傳人。”
與此同時,里希特表示應避免喝生牛奶,因為其中可能含有受感染奶牛的活病毒,應該勤洗手,遇到類似流感的病癥要報告,才可能及時檢測。目前加州州長已宣布進入禽流感緊急狀態,衛生官員向農場工人發放了數百萬件個人防護裝備,各州或許可以仿效。
不過,遏制病毒的各項努力最終很大程度上取決于準確及時的信息傳播,還有政府和衛生界攜手努力抗擊禽流感及相關毒株。
“關于D1.1,還有很多未知之處。未來幾天和幾周內,我們會加班加點地研究,”亨斯利說。在抗擊病毒行動中,專家們將所獲知識廣泛共享將是關鍵。(財富中文網)
譯者:梁宇
審校:夏林
內華達州的奶牛群感染了此前從未在牛身上出現的H5N1禽流感病毒,這一消息披露后引起病毒學家和研究人員高度警惕。而且內華達州農業部發布的消息顯示,想把該病毒從美國牛群中徹底清除,并不像聯邦官員之前宣稱或希望的那般容易。
2月7日又一個打擊接連而至,可能還更嚴重。美國農業部一份技術簡報稱,這種叫D1.1的基因型包含一種基因突變,或許會讓該病毒在包括人類在內的哺乳動物體內更容易復制。
而D1.1版本病毒,正是導致路易斯安那州一名男子死亡,加拿大一名青少年住院且病情危重的病毒變種。該病毒并非去年年初以來在患病牛群中常見的B3.13基因型。
“如果該病毒繼續在奶牛中傳播并感染更多人,可能引發深切關注,”免疫學家、前聯邦衛生官員里克?布萊特向《財富》雜志表示,“目前該突變尚未導致人際傳播加強,所以跡象無法證明其傳播性有所提升。不過比起在奶牛中傳播的(B3.13)病毒,這種病毒一旦感染人類引發的疾病很可能嚴重得多。”
“該病毒蔓延已迫在眉睫,”布萊特補充道,“為預防或降低病毒蔓延的沖擊,相關準備仍然不充分。”
D1.1基因型已在北美遷徙路線的野生鳥類以及哺乳動物和家禽中檢測到,因此傳播到奶牛身上不足為奇。但很多病毒學家認為,內華達州奶牛群中發現標志著H5N1傳播的拐點,意味著人類將面臨更多麻煩。
“D1.1對人類的毒性似乎更大,可能表明在公共衛生風險級別上與早期B3.13毒株相比出現了重大變化,”美國國立衛生研究院(National Institutes of Health)新發及人畜共患傳染病中心主任,也是獸醫學領域領軍人物于爾根?里希特向《財富》雜志表示。
針對一系列郵件提問,美國疾病控制和預防中心(CDC)發言人表示,該機構仍認為該病毒對普通公眾的健康風險很低。“不過,與受感染鳥類或其他動物(包括家畜),或者與受感染鳥類或其他動物污染所處環境有密切、長時間,或無防護措施接觸的人感染風險更高,”發言人表示。
2月7日美國農業部指出,在檢測之前內華達州奶牛并無臨床感染癥狀,但此后有報道稱奶牛已明顯發病,且奶牛場附近出現大批野生鳥類死亡。
人類是否應采取預防措施?風險程度如何?美國的農場和奶牛場是否已采取緩解措施?
種種問題的緊迫性表明,接下來幾周內必須高度重視及時發布聯邦機構的信息及檢測的最新情況,因為研究人員和衛生官員往往依賴相關信息。可惜,當前不能太過指望信息順暢流通。
1月21日,根據特朗普政府的命令,美國衛生與公眾服務部(HHS)凍結了幾乎所有的對外交流,包括文件和健康指導等,直到特朗普任命的官員到任并批準放行。此舉并非沒有先例,但信息凍結在2月1日的截止日期之后仍未完全解除,民主黨領導人開始表示不滿。
特朗普指令有個重大影響,即疾病控制與預防中心發布的《發病率與死亡率周報》(Morbidity and Mortality Weekly Report)受到沖擊。這份報告向來是公共衛生問題的重要信息來源。1 月 23 日,《發病率與死亡率周報》60多年來首次未能按時出版,1月30日再次停刊。2月6日雖恢復發行,《華盛頓郵報》(Washington Post)報道稱其中未提及禽流感,也沒有原定于1月發布的三項 H5N1 研究的信息。
此外據《華爾街日報》(Wall Street Journal)報道,特朗普政府計劃裁減美國衛生與公眾服務部數千名員工。報道稱,政府要求公共衛生高級官員根據員工的工作重要程度排名。
由于種種措施在衛生部門各機構的影響,禽流感追蹤和新藥批準等可能會受到影響。2023年,特朗普提名的衛生與公眾服務部負責人小羅伯特·F·肯尼迪表示,他將對聯邦衛生領域的科學家說,“感謝你們對公眾的服務。接下來八年左右,傳染病(研究)將暫停。”
事態發展導致追蹤H5N1傳播的科學家和研究人員越發擔憂。美國疾病控制與預防中心稱,H5N1現已感染美國959個奶牛群,導致1.56億只家禽死亡,供應短缺推動雞蛋價格創下歷史新高。
研究人員還強烈呼吁,應考慮是否使用聯邦儲備的禽流感疫苗為奶業工人接種,以及在奶牛場和蛋禽養殖場為一線工作人員強制配備個人防護裝備。
各種決策都有賴于信息及時流通和傳播,然而專家表示在這關鍵時刻信息溝通受限。
“想想2020年新冠疫情開始時科學家遭封口,科學傳播受到操縱,現在的情況令人寒心卻毫不奇怪,”疫苗研究員布萊特說,2020年他曾舉報投訴特朗普政府,幾個月來一直敦促衛生官員加強禽流感檢測和預防措施。
布萊特說,“2020年時,疫情應對速度放緩,公眾對科學和公共衛生產生不信任,結果是更多人喪生。令人痛心的是,人們并沒有吸取教訓,當前情況跟當時同樣糟糕乃至更差,不僅是在禽流感方面,美國對眾多其他事件的應對同樣有問題。”
內華達州一名官員向《財富》雜志透露,奶牛感染 D1.1 病毒的新病例追溯至丘吉爾縣的奶牛場,目前已有六個牛群被隔離。此前,內華達州農業局長 J?J?戈伊科切亞曾對路透社表示:“顯然,我們沒能做好充分準備,否則病毒也不會侵入。” 戈伊科切亞稱,內華達州的養殖戶應遵循 “良好的動物健康安全實踐,并加強生物安全措施”。
這一切對人類意味著什么?按照薩斯喀徹溫大學(University of Saskatchewan)病毒學家安吉拉·拉斯穆森的說法,內華達州的疫情并不會直接增加人傳人的可能性,只是“增加了動物傳人的風險,也就是從奶牛傳給農場工人”。除此之外,真正讓研究人員感到擔憂的是D1.1的突變能力(或許B3.13尚未出現類似突變)。其適應能力可能導致病毒更容易在人際傳播。
“在已知的少數人類感染病例中,H5N1病毒的新基因型D1.1會導致嚴重疾病甚至死亡,”布萊特說,“內華達州的病例意義重大,因為現在我們清楚地知道H5N1病毒在奶牛之間,以及從一個農場到另一個農場傳播多么容易。病毒不僅能從牛奶傳播到其他哺乳動物,比如老鼠和貓,還能感染人類。”
內布拉斯加大學(University of Nebraska)全球衛生安全中心主任詹姆斯·勞勒表示,近幾個月來,聯邦衛生機構采取了“一些積極措施”,通過全美牛奶檢測戰略增加檢測,還對人類進行流感檢測和亞型分析。
“為了更好地控制風險,我們應該加強受感染奶牛群和動物的檢測與隔離,推動更廣泛的人類監測和檢測,加快疫苗研發與生產。”勞勒說。布萊特還表示,臨床醫生需要知道病毒正在傳播,而且要“檢測流感,而不是靠猜。”
賓夕法尼亞大學(University of Pennsylvania)病毒免疫學家斯科特·亨斯利表示贊同,“我們要密切監測D1.1病毒,因為病毒已表現出適應能力,而且能引發人類罹患嚴重疾病。”亨斯利還提到,“現有的H5N1疫苗儲備與D1.1病毒匹配良好,有望提供高度防護。仍需加快H5N1疫苗生產,以防病毒演化到人傳人。”
與此同時,里希特表示應避免喝生牛奶,因為其中可能含有受感染奶牛的活病毒,應該勤洗手,遇到類似流感的病癥要報告,才可能及時檢測。目前加州州長已宣布進入禽流感緊急狀態,衛生官員向農場工人發放了數百萬件個人防護裝備,各州或許可以仿效。
不過,遏制病毒的各項努力最終很大程度上取決于準確及時的信息傳播,還有政府和衛生界攜手努力抗擊禽流感及相關毒株。
“關于D1.1,還有很多未知之處。未來幾天和幾周內,我們會加班加點地研究,”亨斯利說。在抗擊病毒行動中,專家們將所獲知識廣泛共享將是關鍵。(財富中文網)
譯者:梁宇
審校:夏林
The disclosure that dairy herds in Nevada have been infected by a version of the H5N1 bird flu not previously seen in cows, has put virologists and researchers on high alert. Among other things, the news from the Nevada Department of Agriculture, suggests that driving the virus out of the U.S. cattle population won’t be nearly as simple as federal officials once suggested—or perhaps hoped.
On Friday came a second and potentially more serious blow: A technical brief by the U.S. Department of Agriculture reported that the genotype, known as D1.1, contains a genetic mutation that may help the virus more easily copy itself in mammals—including humans.
This D1.1 version of the virus is the same variant that killed a man in Louisiana and left a Canadian teen hospitalized in critical condition. It is not the B3.13 genotype widely found in sick cattle dating to early last year.
“This can be of significant concern if this virus continues to spread among cows and infects more people,” immunologist and former federal health official Rick Bright tells Fortune. “This mutation has not been associated with improved human transmission, so there are no telling signs of enhanced spread yet. But when this virus gets into people, it is ready to cause a much more serious disease than the (B3.13) virus that has been circulating in cows before now.
“We have never been closer to a pandemic from this virus,” Bright adds. “And we still are not doing everything possible to prevent it or reduce the impact if it hits.”
The D1.1 genotype has been detected in wild birds in all North American flyways, as well as mammals and poultry, so it isn’t surprising that it’s made the leap to cows. But its newfound presence in the Nevada dairy herds is considered by many virologists to mark a sort of inflection point in the spread of H5N1, and it could spell more trouble for humans going forward.
“Given the fact that D1.1 seems to be more virulent in humans, this could indicate a major change in terms of public health risks from the earlier scenario with the B3.13 strain,” veterinary science pioneer Juergen Richt, Director of the National Institutes of Health Center on Emerging and Zoonotic Infectious Diseases, tells Fortune.
In response to an emailed series of questions, a spokesperson for the federal Centers for Disease Control and Prevention (CDC) said the agency still deems the risk to human health for the general public to be low. “However, people with close, prolonged, or unprotected exposures to infected birds or other animals (including livestock), or to environments contaminated by infected birds or other animals, are at greater risk of infection,” the spokesperson said.
The USDA on Friday noted that although the Nevada cattle did not display clinical signs of infection prior to its detection via testing, such signs have since been reported, along with die-offs of a large number of wild birds near the affected dairies.
Should humans be taking more precautions? What is the scope of the risk? And are there mitigating actions that should already be in place on America’s farms and dairies?
The urgency of those questions suggests that in the coming weeks, an absolute premium should be placed upon the timely dissemination of information and testing updates from the federal sources upon which researchers and health officials often rely. But that information flow is no longer to be taken for granted.
On Jan. 21, under orders from the Trump administration, the U.S. Department of Health and Human Services (HHS) placed a freeze on almost all external communications, including documents and health guidance, until a Trump-appointed official could be installed and approve them. Such a move is not unprecedented, but when the information freeze blew past its Feb. 1 deadline without being fully lifted, Democratic leaders began crying foul.
One important casualty of that action was the CDC’s Morbidity and Mortality Weekly Report. The MMWR, as it’s known, is a critical source of information on public health issues. The MMWR failed to publish for the first time in more than sixty years on January 23rd and again on January 30th. Publication did resume on February 6th, but there was no mention of bird flu nor any information about the three H5N1 studies which were scheduled to be published in January according to the Washington Post.
Further, per the Wall Street Journal, the Trump administration is reportedly planning to eliminate the jobs of thousands of U.S. Department of Health and Human Services (HHS) employees. Senior public-health officials are reportedly being told to rank employees based on how critical their roles are.
Depending upon where those cuts land across the various agencies of the department, practices like tracing bird-flu outbreaks and approving new drugs could be affected. And Trump’s nominee to run HHS, Robert F. Kennedy Jr., in 2023 said he’d tell federal health scientists, “Thank you for your public service. We’re going to give [studying] infectious diseases a break for about eight years.”
These developments have ramped up the concern of scientists and researchers tracking the spread of H5N1, which, according to the CDC, has now infected 959 dairy herds in the U.S. and been responsible for the death of 156 million poultry, sending the price of eggs to record highs because of scarce supply.
Researchers are also loudly asking whether dairy workers should be vaccinated using existing supplies from the federal stock of bird flu vaccine, and whether personal protective equipment should become mandatory on dairy farms and egg-laying facilities for frontline workers.
This all comes back to the timely flow of information and communication—and, experts say, it is being throttled at a critical moment.
“This is chilling but not at all surprising, given the gag put on scientists and the manipulation of scientific communication in 2020 at the start of the COVID pandemic,” says Bright, a vaccine researcher who filed a whistleblower complaint against the Trump administration in 2020 and has been urging health officials for months to ramp up testing and precautions around bird flu.
“When it happened in 2020,” Bright says, “it slowed the response, sowed distrust in science and public health, and as a consequence many more people died during that time. It is horrifying that lessons were not learned, and we find ourselves in the same or worse situation–not only on H5N1, but on numerous ongoing outbreaks in the U.S.”
A Nevada official tells Fortune that the new cases of D1.1 in cows were traced to dairy farms in Churchill County, with six herds placed under quarantine. Previously, the state’s agriculture director, J.J. Goicoechea, told Reuters, “We obviously aren’t doing everything we can and everything we should, or the virus wouldn’t be getting in.” Goicoechea said Nevada farmers needed to follow “good animal health safety practices and bolster biosecurity measures” for their animals.
Where does this all leave humans? According to University of Saskatchewan virologist Angela Rasmussen, the development in Nevada doesn’t directly increase the likelihood of human-to-human transmission, but rather “increases risk of zoonotic human cases—that is, from cows to farmworkers. Beyond that, it is D1.1’s ability to mutate (perhaps in ways B3.13 has not mutated) that concerns researchers. That adaptability may allow the virus to more easily spread from person to person.
“This new genotype of H5N1 virus, D1.1 was associated with more severe illness and death in the few known human infections,” Bright says. “It (the Nevada case) is a significant event, because we now know how easily H5N1 viruses can spread among dairy cows, from farm to farm, jump from milk to other mammals, including mice and cats, and even infect people.”
Federal health agencies have taken “some positive steps” in recent months to increase testing via a National Milk Testing Strategy, and of testing and subtyping influenza in people, says James Lawler, director of the University of Nebraska’s Global Center for Health Security.
“To better control risk, however, we should aggressively ramp up testing and isolation of affected dairy herds and animals, facilitate more widespread surveillance and testing in people, and accelerate vaccine development and production,” Lawler says. Clinicians also need to know that the virus is circulating, Bright says, and to “test for influenza, not guess.”
Scott Hensley, a viral immunologist at the University of Pennsylvania, agrees. “We need to closely monitor D1.1 viruses because they have already shown the ability to adapt and cause severe disease in humans,” Hensley says. “Our H5N1 vaccine stocks are well matched to the D1.1 viruses and would likely provide high levels of protection—we need to ramp up H5N1 vaccine production in case these viruses evolve to spread from human to human.”
In the meantime, Richt says, people need to avoid drinking raw milk, which might contain live virus from infected dairy cows, wash their hands often and report influenza-like illnesses, presumably so that tests can be run. States may follow the lead of California, where the governor declared a bird flu emergency and health officials have facilitated the distribution of millions of pieces of personal protective equipment to farmworkers.
Every effort to contain the virus, though, ultimately will depend to a tremendous extent on the distribution of accurate and timely information—and a government and health community that commits to fighting bird flu and its concerning strains.
“There is a lot that we do not know about D1.1. viruses, and we will all be working overtime to learn more in the coming days and weeks,” Hensley says. It is the mass sharing of what experts learn that will be most critical in the fight.