国产一精品一AV一免费,亚洲成AV人片不卡无码,AV永久天堂一区二区三区,国产激情久久久久影院

首頁(yè) 500強(qiáng) 活動(dòng) 榜單 商業(yè) 科技 商潮 專題 品牌中心
雜志訂閱

內(nèi)華達(dá)州奶牛中發(fā)現(xiàn)新型禽流感變種,專家拉響警報(bào)

Carolyn Barber
2025-02-16

內(nèi)華達(dá)州的奶牛群感染了此前從未在牛身上出現(xiàn)的H5N1禽流感病毒,病毒學(xué)家對(duì)此高度警惕。

文本設(shè)置
小號(hào)
默認(rèn)
大號(hào)
Plus(0條)

圖片來源:Getty Images

內(nèi)華達(dá)州的奶牛群感染了此前從未在牛身上出現(xiàn)的H5N1禽流感病毒,這一消息披露后引起病毒學(xué)家和研究人員高度警惕。而且內(nèi)華達(dá)州農(nóng)業(yè)部發(fā)布的消息顯示,想把該病毒從美國(guó)牛群中徹底清除,并不像聯(lián)邦官員之前宣稱或希望的那般容易。

2月7日又一個(gè)打擊接連而至,可能還更嚴(yán)重。美國(guó)農(nóng)業(yè)部一份技術(shù)簡(jiǎn)報(bào)稱,這種叫D1.1的基因型包含一種基因突變,或許會(huì)讓該病毒在包括人類在內(nèi)的哺乳動(dòng)物體內(nèi)更容易復(fù)制。

而D1.1版本病毒,正是導(dǎo)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(xù)在奶牛中傳播并感染更多人,可能引發(fā)深切關(guān)注,”免疫學(xué)家、前聯(lián)邦衛(wèi)生官員里克?布萊特向《財(cái)富》雜志表示,“目前該突變尚未導(dǎo)致人際傳播加強(qiáng),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(fā)的疾病很可能嚴(yán)重得多。”

“該病毒蔓延已迫在眉睫,”布萊特補(bǔ)充道,“為預(yù)防或降低病毒蔓延的沖擊,相關(guān)準(zhǔn)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(dòng)物和家禽中檢測(cè)到,因此傳播到奶牛身上不足為奇。但很多病毒學(xué)家認(rèn)為,內(nèi)華達(dá)州奶牛群中發(fā)現(xiàn)標(biāo)志著H5N1傳播的拐點(diǎn),意味著人類將面臨更多麻煩。

“D1.1對(duì)人類的毒性似乎更大,可能表明在公共衛(wèi)生風(fēng)險(xiǎn)級(jí)別上與早期B3.13毒株相比出現(xiàn)了重大變化,”美國(guó)國(guó)立衛(wèi)生研究院(National Institutes of Health)新發(fā)及人畜共患傳染病中心主任,也是獸醫(yī)學(xué)領(lǐng)域領(lǐng)軍人物于爾根?里希特向《財(cái)富》雜志表示。

針對(duì)一系列郵件提問,美國(guó)疾病控制和預(yù)防中心(CDC)發(fā)言人表示,該機(jī)構(gòu)仍認(rèn)為該病毒對(duì)普通公眾的健康風(fēng)險(xiǎn)很低?!安贿^,與受感染鳥類或其他動(dòng)物(包括家畜),或者與受感染鳥類或其他動(dòng)物污染所處環(huán)境有密切、長(zhǎng)時(shí)間,或無防護(hù)措施接觸的人感染風(fēng)險(xiǎn)更高,”發(fā)言人表示。

2月7日美國(guó)農(nóng)業(yè)部指出,在檢測(cè)之前內(nèi)華達(dá)州奶牛并無臨床感染癥狀,但此后有報(bào)道稱奶牛已明顯發(fā)病,且奶牛場(chǎng)附近出現(xiàn)大批野生鳥類死亡。

人類是否應(yīng)采取預(yù)防措施?風(fēng)險(xiǎn)程度如何?美國(guó)的農(nóng)場(chǎng)和奶牛場(chǎng)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(nèi)必須高度重視及時(shí)發(fā)布聯(lián)邦機(jī)構(gòu)的信息及檢測(cè)的最新情況,因?yàn)檠芯咳藛T和衛(wèi)生官員往往依賴相關(guān)信息??上В?dāng)前不能太過指望信息順暢流通。

1月21日,根據(jù)特朗普政府的命令,美國(guó)衛(wèi)生與公眾服務(wù)部(HHS)凍結(jié)了幾乎所有的對(duì)外交流,包括文件和健康指導(dǎo)等,直到特朗普任命的官員到任并批準(zhǔn)放行。此舉并非沒有先例,但信息凍結(jié)在2月1日的截止日期之后仍未完全解除,民主黨領(lǐng)導(dǎo)人開始表示不滿。

特朗普指令有個(gè)重大影響,即疾病控制與預(yù)防中心發(fā)布的《發(fā)病率與死亡率周報(bào)》(Morbidity and Mortality Weekly Report)受到?jīng)_擊。這份報(bào)告向來是公共衛(wèi)生問題的重要信息來源。1 月 23 日,《發(fā)病率與死亡率周報(bào)》60多年來首次未能按時(shí)出版,1月30日再次???月6日雖恢復(fù)發(fā)行,《華盛頓郵報(bào)》(Washington Post)報(bào)道稱其中未提及禽流感,也沒有原定于1月發(fā)布的三項(xiàng) H5N1 研究的信息。

此外據(jù)《華爾街日?qǐng)?bào)》(Wall Street Journal)報(bào)道,特朗普政府計(jì)劃裁減美國(guó)衛(wèi)生與公眾服務(wù)部數(shù)千名員工。報(bào)道稱,政府要求公共衛(wèi)生高級(jí)官員根據(jù)員工的工作重要程度排名。

由于種種措施在衛(wèi)生部門各機(jī)構(gòu)的影響,禽流感追蹤和新藥批準(zhǔn)等可能會(huì)受到影響。2023年,特朗普提名的衛(wèi)生與公眾服務(wù)部負(fù)責(zé)人小羅伯特·F·肯尼迪表示,他將對(duì)聯(lián)邦衛(wèi)生領(lǐng)域的科學(xué)家說,“感謝你們對(duì)公眾的服務(wù)。接下來八年左右,傳染?。ㄑ芯浚和!!?/p>

事態(tài)發(fā)展導(dǎo)致追蹤H5N1傳播的科學(xué)家和研究人員越發(fā)擔(dān)憂。美國(guó)疾病控制與預(yù)防中心稱,H5N1現(xiàn)已感染美國(guó)959個(gè)奶牛群,導(dǎo)致1.56億只家禽死亡,供應(yīng)短缺推動(dòng)雞蛋價(jià)格創(chuàng)下歷史新高。

研究人員還強(qiáng)烈呼吁,應(yīng)考慮是否使用聯(lián)邦儲(chǔ)備的禽流感疫苗為奶業(yè)工人接種,以及在奶牛場(chǎng)和蛋禽養(yǎng)殖場(chǎng)為一線工作人員強(qiáng)制配備個(gè)人防護(hù)裝備。

各種決策都有賴于信息及時(shí)流通和傳播,然而專家表示在這關(guān)鍵時(shí)刻信息溝通受限。

“想想2020年新冠疫情開始時(shí)科學(xué)家遭封口,科學(xué)傳播受到操縱,現(xiàn)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(bào)投訴特朗普政府,幾個(gè)月來一直敦促衛(wèi)生官員加強(qiáng)禽流感檢測(cè)和預(yù)防措施。

布萊特說,“2020年時(shí),疫情應(yīng)對(duì)速度放緩,公眾對(duì)科學(xué)和公共衛(wèi)生產(chǎn)生不信任,結(jié)果是更多人喪生。令人痛心的是,人們并沒有吸取教訓(xùn),當(dāng)前情況跟當(dāng)時(shí)同樣糟糕乃至更差,不僅是在禽流感方面,美國(guó)對(duì)眾多其他事件的應(yīng)對(duì)同樣有問題?!?/p>

內(nèi)華達(dá)州一名官員向《財(cái)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(chǎng),目前已有六個(gè)牛群被隔離。此前,內(nèi)華達(dá)州農(nóng)業(yè)局長(zhǎng) J?J?戈伊科切亞曾對(duì)路透社表示:“顯然,我們沒能做好充分準(zhǔn)備,否則病毒也不會(huì)侵入?!?戈伊科切亞稱,內(nèi)華達(dá)州的養(yǎng)殖戶應(yīng)遵循 “良好的動(dòng)物健康安全實(shí)踐,并加強(qiáng)生物安全措施”。

這一切對(duì)人類意味著什么?按照薩斯喀徹溫大學(xué)(University of Saskatchewan)病毒學(xué)家安吉拉·拉斯穆森的說法,內(nèi)華達(dá)州的疫情并不會(huì)直接增加人傳人的可能性,只是“增加了動(dòng)物傳人的風(fēng)險(xiǎn),也就是從奶牛傳給農(nóng)場(chǎng)工人”。除此之外,真正讓研究人員感到擔(dān)憂的是D1.1的突變能力(或許B3.13尚未出現(xiàn)類似突變)。其適應(yīng)能力可能導(dǎo)致病毒更容易在人際傳播。

“在已知的少數(shù)人類感染病例中,H5N1病毒的新基因型D1.1會(huì)導(dǎo)致嚴(yán)重疾病甚至死亡,”布萊特說,“內(nèi)華達(dá)州的病例意義重大,因?yàn)楝F(xiàn)在我們清楚地知道H5N1病毒在奶牛之間,以及從一個(gè)農(nóng)場(chǎng)到另一個(gè)農(nóng)場(chǎng)傳播多么容易。病毒不僅能從牛奶傳播到其他哺乳動(dòng)物,比如老鼠和貓,還能感染人類。”

內(nèi)布拉斯加大學(xué)(University of Nebraska)全球衛(wèi)生安全中心主任詹姆斯·勞勒表示,近幾個(gè)月來,聯(lián)邦衛(wèi)生機(jī)構(gòu)采取了“一些積極措施”,通過全美牛奶檢測(cè)戰(zhàn)略增加檢測(cè),還對(duì)人類進(jìn)行流感檢測(cè)和亞型分析。

“為了更好地控制風(fēng)險(xiǎn),我們應(yīng)該加強(qiáng)受感染奶牛群和動(dòng)物的檢測(cè)與隔離,推動(dòng)更廣泛的人類監(jiān)測(cè)和檢測(cè),加快疫苗研發(fā)與生產(chǎn)?!眲诶照f。布萊特還表示,臨床醫(yī)生需要知道病毒正在傳播,而且要“檢測(cè)流感,而不是靠猜?!?/p>

賓夕法尼亞大學(xué)(University of Pennsylvania)病毒免疫學(xué)家斯科特·亨斯利表示贊同,“我們要密切監(jiān)測(cè)D1.1病毒,因?yàn)椴《疽驯憩F(xiàn)出適應(yīng)能力,而且能引發(fā)人類罹患嚴(yán)重疾病?!焙嗨估€提到,“現(xiàn)有的H5N1疫苗儲(chǔ)備與D1.1病毒匹配良好,有望提供高度防護(hù)。仍需加快H5N1疫苗生產(chǎn),以防病毒演化到人傳人?!?/p>

與此同時(shí),里希特表示應(yīng)避免喝生牛奶,因?yàn)槠渲锌赡芎惺芨腥灸膛5幕畈《荆瑧?yīng)該勤洗手,遇到類似流感的病癥要報(bào)告,才可能及時(shí)檢測(cè)。目前加州州長(zhǎng)已宣布進(jìn)入禽流感緊急狀態(tài),衛(wèi)生官員向農(nóng)場(chǎng)工人發(fā)放了數(shù)百萬件個(gè)人防護(hù)裝備,各州或許可以仿效。

不過,遏制病毒的各項(xiàng)努力最終很大程度上取決于準(zhǔn)確及時(shí)的信息傳播,還有政府和衛(wèi)生界攜手努力抗擊禽流感及相關(guān)毒株。

“關(guān)于D1.1,還有很多未知之處。未來幾天和幾周內(nèi),我們會(huì)加班加點(diǎn)地研究,”亨斯利說。在抗擊病毒行動(dòng)中,專家們將所獲知識(shí)廣泛共享將是關(guān)鍵。(財(cái)富中文網(wǎng))

譯者:梁宇

審校:夏林

內(nèi)華達(dá)州的奶牛群感染了此前從未在牛身上出現(xiàn)的H5N1禽流感病毒,這一消息披露后引起病毒學(xué)家和研究人員高度警惕。而且內(nèi)華達(dá)州農(nóng)業(yè)部發(fā)布的消息顯示,想把該病毒從美國(guó)牛群中徹底清除,并不像聯(lián)邦官員之前宣稱或希望的那般容易。

2月7日又一個(gè)打擊接連而至,可能還更嚴(yán)重。美國(guó)農(nóng)業(yè)部一份技術(shù)簡(jiǎn)報(bào)稱,這種叫D1.1的基因型包含一種基因突變,或許會(huì)讓該病毒在包括人類在內(nèi)的哺乳動(dòng)物體內(nèi)更容易復(fù)制。

而D1.1版本病毒,正是導(dǎo)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(xù)在奶牛中傳播并感染更多人,可能引發(fā)深切關(guān)注,”免疫學(xué)家、前聯(lián)邦衛(wèi)生官員里克?布萊特向《財(cái)富》雜志表示,“目前該突變尚未導(dǎo)致人際傳播加強(qiáng),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(fā)的疾病很可能嚴(yán)重得多。”

“該病毒蔓延已迫在眉睫,”布萊特補(bǔ)充道,“為預(yù)防或降低病毒蔓延的沖擊,相關(guān)準(zhǔn)備仍然不充分?!?/p>

D1.1基因型已在北美遷徙路線的野生鳥類以及哺乳動(dòng)物和家禽中檢測(cè)到,因此傳播到奶牛身上不足為奇。但很多病毒學(xué)家認(rèn)為,內(nèi)華達(dá)州奶牛群中發(fā)現(xiàn)標(biāo)志著H5N1傳播的拐點(diǎn),意味著人類將面臨更多麻煩。

“D1.1對(duì)人類的毒性似乎更大,可能表明在公共衛(wèi)生風(fēng)險(xiǎn)級(jí)別上與早期B3.13毒株相比出現(xiàn)了重大變化,”美國(guó)國(guó)立衛(wèi)生研究院(National Institutes of Health)新發(fā)及人畜共患傳染病中心主任,也是獸醫(yī)學(xué)領(lǐng)域領(lǐng)軍人物于爾根?里希特向《財(cái)富》雜志表示。

針對(duì)一系列郵件提問,美國(guó)疾病控制和預(yù)防中心(CDC)發(fā)言人表示,該機(jī)構(gòu)仍認(rèn)為該病毒對(duì)普通公眾的健康風(fēng)險(xiǎn)很低?!安贿^,與受感染鳥類或其他動(dòng)物(包括家畜),或者與受感染鳥類或其他動(dòng)物污染所處環(huán)境有密切、長(zhǎng)時(shí)間,或無防護(hù)措施接觸的人感染風(fēng)險(xiǎn)更高,”發(fā)言人表示。

2月7日美國(guó)農(nóng)業(yè)部指出,在檢測(cè)之前內(nèi)華達(dá)州奶牛并無臨床感染癥狀,但此后有報(bào)道稱奶牛已明顯發(fā)病,且奶牛場(chǎng)附近出現(xiàn)大批野生鳥類死亡。

人類是否應(yīng)采取預(yù)防措施?風(fēng)險(xiǎn)程度如何?美國(guó)的農(nóng)場(chǎng)和奶牛場(chǎng)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(nèi)必須高度重視及時(shí)發(fā)布聯(lián)邦機(jī)構(gòu)的信息及檢測(cè)的最新情況,因?yàn)檠芯咳藛T和衛(wèi)生官員往往依賴相關(guān)信息??上В?dāng)前不能太過指望信息順暢流通。

1月21日,根據(jù)特朗普政府的命令,美國(guó)衛(wèi)生與公眾服務(wù)部(HHS)凍結(jié)了幾乎所有的對(duì)外交流,包括文件和健康指導(dǎo)等,直到特朗普任命的官員到任并批準(zhǔn)放行。此舉并非沒有先例,但信息凍結(jié)在2月1日的截止日期之后仍未完全解除,民主黨領(lǐng)導(dǎo)人開始表示不滿。

特朗普指令有個(gè)重大影響,即疾病控制與預(yù)防中心發(fā)布的《發(fā)病率與死亡率周報(bào)》(Morbidity and Mortality Weekly Report)受到?jīng)_擊。這份報(bào)告向來是公共衛(wèi)生問題的重要信息來源。1 月 23 日,《發(fā)病率與死亡率周報(bào)》60多年來首次未能按時(shí)出版,1月30日再次???月6日雖恢復(fù)發(fā)行,《華盛頓郵報(bào)》(Washington Post)報(bào)道稱其中未提及禽流感,也沒有原定于1月發(fā)布的三項(xiàng) H5N1 研究的信息。

此外據(jù)《華爾街日?qǐng)?bào)》(Wall Street Journal)報(bào)道,特朗普政府計(jì)劃裁減美國(guó)衛(wèi)生與公眾服務(wù)部數(shù)千名員工。報(bào)道稱,政府要求公共衛(wèi)生高級(jí)官員根據(jù)員工的工作重要程度排名。

由于種種措施在衛(wèi)生部門各機(jī)構(gòu)的影響,禽流感追蹤和新藥批準(zhǔn)等可能會(huì)受到影響。2023年,特朗普提名的衛(wèi)生與公眾服務(wù)部負(fù)責(zé)人小羅伯特·F·肯尼迪表示,他將對(duì)聯(lián)邦衛(wèi)生領(lǐng)域的科學(xué)家說,“感謝你們對(duì)公眾的服務(wù)。接下來八年左右,傳染?。ㄑ芯浚和!!?/p>

事態(tài)發(fā)展導(dǎo)致追蹤H5N1傳播的科學(xué)家和研究人員越發(fā)擔(dān)憂。美國(guó)疾病控制與預(yù)防中心稱,H5N1現(xiàn)已感染美國(guó)959個(gè)奶牛群,導(dǎo)致1.56億只家禽死亡,供應(yīng)短缺推動(dòng)雞蛋價(jià)格創(chuàng)下歷史新高。

研究人員還強(qiáng)烈呼吁,應(yīng)考慮是否使用聯(lián)邦儲(chǔ)備的禽流感疫苗為奶業(yè)工人接種,以及在奶牛場(chǎng)和蛋禽養(yǎng)殖場(chǎng)為一線工作人員強(qiáng)制配備個(gè)人防護(hù)裝備。

各種決策都有賴于信息及時(shí)流通和傳播,然而專家表示在這關(guān)鍵時(shí)刻信息溝通受限。

“想想2020年新冠疫情開始時(shí)科學(xué)家遭封口,科學(xué)傳播受到操縱,現(xiàn)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(bào)投訴特朗普政府,幾個(gè)月來一直敦促衛(wèi)生官員加強(qiáng)禽流感檢測(cè)和預(yù)防措施。

布萊特說,“2020年時(shí),疫情應(yīng)對(duì)速度放緩,公眾對(duì)科學(xué)和公共衛(wèi)生產(chǎn)生不信任,結(jié)果是更多人喪生。令人痛心的是,人們并沒有吸取教訓(xùn),當(dāng)前情況跟當(dāng)時(shí)同樣糟糕乃至更差,不僅是在禽流感方面,美國(guó)對(duì)眾多其他事件的應(yīng)對(duì)同樣有問題?!?/p>

內(nèi)華達(dá)州一名官員向《財(cái)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(chǎng),目前已有六個(gè)牛群被隔離。此前,內(nèi)華達(dá)州農(nóng)業(yè)局長(zhǎng) J?J?戈伊科切亞曾對(duì)路透社表示:“顯然,我們沒能做好充分準(zhǔn)備,否則病毒也不會(huì)侵入。” 戈伊科切亞稱,內(nèi)華達(dá)州的養(yǎng)殖戶應(yīng)遵循 “良好的動(dòng)物健康安全實(shí)踐,并加強(qiáng)生物安全措施”。

這一切對(duì)人類意味著什么?按照薩斯喀徹溫大學(xué)(University of Saskatchewan)病毒學(xué)家安吉拉·拉斯穆森的說法,內(nèi)華達(dá)州的疫情并不會(huì)直接增加人傳人的可能性,只是“增加了動(dòng)物傳人的風(fēng)險(xiǎn),也就是從奶牛傳給農(nóng)場(chǎng)工人”。除此之外,真正讓研究人員感到擔(dān)憂的是D1.1的突變能力(或許B3.13尚未出現(xiàn)類似突變)。其適應(yīng)能力可能導(dǎo)致病毒更容易在人際傳播。

“在已知的少數(shù)人類感染病例中,H5N1病毒的新基因型D1.1會(huì)導(dǎo)致嚴(yán)重疾病甚至死亡,”布萊特說,“內(nèi)華達(dá)州的病例意義重大,因?yàn)楝F(xiàn)在我們清楚地知道H5N1病毒在奶牛之間,以及從一個(gè)農(nóng)場(chǎng)到另一個(gè)農(nóng)場(chǎng)傳播多么容易。病毒不僅能從牛奶傳播到其他哺乳動(dòng)物,比如老鼠和貓,還能感染人類?!?/p>

內(nèi)布拉斯加大學(xué)(University of Nebraska)全球衛(wèi)生安全中心主任詹姆斯·勞勒表示,近幾個(gè)月來,聯(lián)邦衛(wèi)生機(jī)構(gòu)采取了“一些積極措施”,通過全美牛奶檢測(cè)戰(zhàn)略增加檢測(cè),還對(duì)人類進(jìn)行流感檢測(cè)和亞型分析。

“為了更好地控制風(fēng)險(xiǎn),我們應(yīng)該加強(qiáng)受感染奶牛群和動(dòng)物的檢測(cè)與隔離,推動(dòng)更廣泛的人類監(jiān)測(cè)和檢測(cè),加快疫苗研發(fā)與生產(chǎn)?!眲诶照f。布萊特還表示,臨床醫(yī)生需要知道病毒正在傳播,而且要“檢測(cè)流感,而不是靠猜?!?/p>

賓夕法尼亞大學(xué)(University of Pennsylvania)病毒免疫學(xué)家斯科特·亨斯利表示贊同,“我們要密切監(jiān)測(cè)D1.1病毒,因?yàn)椴《疽驯憩F(xiàn)出適應(yīng)能力,而且能引發(fā)人類罹患嚴(yán)重疾病?!焙嗨估€提到,“現(xiàn)有的H5N1疫苗儲(chǔ)備與D1.1病毒匹配良好,有望提供高度防護(hù)。仍需加快H5N1疫苗生產(chǎn),以防病毒演化到人傳人?!?/p>

與此同時(shí),里希特表示應(yīng)避免喝生牛奶,因?yàn)槠渲锌赡芎惺芨腥灸膛5幕畈《荆瑧?yīng)該勤洗手,遇到類似流感的病癥要報(bào)告,才可能及時(shí)檢測(cè)。目前加州州長(zhǎng)已宣布進(jìn)入禽流感緊急狀態(tài),衛(wèi)生官員向農(nóng)場(chǎng)工人發(fā)放了數(shù)百萬件個(gè)人防護(hù)裝備,各州或許可以仿效。

不過,遏制病毒的各項(xiàng)努力最終很大程度上取決于準(zhǔn)確及時(shí)的信息傳播,還有政府和衛(wèi)生界攜手努力抗擊禽流感及相關(guān)毒株。

“關(guān)于D1.1,還有很多未知之處。未來幾天和幾周內(nèi),我們會(huì)加班加點(diǎn)地研究,”亨斯利說。在抗擊病毒行動(dòng)中,專家們將所獲知識(shí)廣泛共享將是關(guān)鍵。(財(cái)富中文網(wǎng))

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.

財(cái)富中文網(wǎng)所刊載內(nèi)容之知識(shí)產(chǎn)權(quán)為財(cái)富媒體知識(shí)產(chǎn)權(quán)有限公司及/或相關(guān)權(quán)利人專屬所有或持有。未經(jīng)許可,禁止進(jìn)行轉(zhuǎn)載、摘編、復(fù)制及建立鏡像等任何使用。
0條Plus
精彩評(píng)論
評(píng)論

撰寫或查看更多評(píng)論

請(qǐng)打開財(cái)富Plus APP

前往打開
熱讀文章
大安市| 宜兰县| 西贡区| 师宗县| 安化县| 苏尼特右旗| 牡丹江市| 黎平县| 沈丘县| 安龙县| 崇仁县| 达尔| 舟山市| 吉首市| 阳原县| 深水埗区| 隆回县| 许昌市| 邹城市| 两当县| 南投市| 宜川县| 阜阳市| 河津市| 南康市| 资源县| 宜春市| 昭平县| 丰宁| 南阳市| 精河县| 东方市| 朝阳县| 巴楚县| 平昌县| 新余市| 安义县| 左贡县| 商水县| 焦作市| 奉化市|