美国农业部确认俄勒冈州一奶牛群检出高致病性禽流感 为该州牛群首例
美国农业部11月10日宣布，旗下动植物卫生检验局（APHIS）国家兽医服务实验室经 PCR 检测确认，俄勒冈州一个奶牛群检出高致病性禽流感（HPAI）H5 分支 2.3.4.4b，这是俄勒冈州首次在牛群中报告此类病例。
该牛群是在俄勒冈州持续进行的奶牛禽流感监测中受检的，此前在国家牛奶检测战略计划下的例行监测中一直呈阴性。农业部表示，基因测序正在进行，结果出来后将尽快公布。自2024年3月疫情暴发以来，全美已有22个州的奶牛受到感染，今年也出现了此前未受影响的州报告病例。
动植物卫生检验局正与俄勒冈州农业厅密切合作，在牧场开展进一步调查、诊断检测和流行病学数据收集，以弄清这次检出的来由并防止疾病进一步传播。农业部表示，这次检出不改变其禽流感根除战略，生物安全仍是降低疾病传入与传播风险的关键，牧场主如发现牲畜出现临床症状，或发现异常生病、死亡的野生动物，应立即报告州兽医。
农业部强调，这次检出不危及消费者健康，也不影响商业牛奶供应的安全。食品药品监管局 FDA 表示，巴氏杀菌能有效灭活禽流感病毒，商业巴氏杀菌牛奶供应是安全的。奶牛场只能把健康动物的牛奶送去加工供人饮用，受影响动物的牛奶会被分流或销毁，不会进入人类食品供应。疾控中心 CDC 表示，目前在禽类和美国奶牛中传播的禽流感病毒对美国公众的风险较低，不过因工作或休闲活动接触受感染禽类或哺乳动物的人感染风险更高，应按 CDC 指引采取防护措施。
（来源：美国农业部）
USDA Confirms Highly Pathogenic Avian Influenza in an Oregon Dairy Herd, the First Case in Cattle in the State
The U.S. Department of Agriculture announced on November 10 that the National Veterinary Services Laboratories of its Animal and Plant Health Inspection Service (APHIS) had confirmed, by PCR testing, highly pathogenic avian influenza (HPAI) H5 clade 2.3.4.4b in a dairy cattle herd in Oregon, the first reported case of HPAI in cattle in the state.
The herd was tested as part of Oregon's ongoing surveillance for HPAI in dairy cattle and had consistently tested negative through routine surveillance under the National Milk Testing Strategy program. APHIS said genetic sequencing will be completed and final results announced as soon as they are available. Dairy cattle in a total of 22 states have been infected since the outbreak began in March 2024, and APHIS has seen cases in previously unaffected states this year.
APHIS is working closely with the Oregon Department of Agriculture to conduct additional on-farm investigations, diagnostic testing and epidemiological data collection to better understand the detection and prevent further spread. The detection does not change USDA's HPAI eradication strategy, and biosecurity remains key to mitigating the risk of disease introduction or spread between premises. Producers should immediately report livestock with clinical signs, or any unusual sick or dead wildlife, to their state veterinarian.
USDA said the detection does not pose a risk to consumer health or affect the safety of the commercial milk supply. The Food and Drug Administration is confident that pasteurization is effective at inactivating the HPAI virus and that the commercial, pasteurized milk supply is safe. Dairies may send only milk from healthy animals into processing for human consumption, and milk from impacted animals is diverted from the commercial milk tank or destroyed. According to the Centers for Disease Control and Prevention, HPAI viruses circulating in birds and U.S. dairy cattle pose a low risk to the general public, though people with job-related or recreational exposure to infected birds or mammals are at higher risk and should take the precautions outlined in CDC guidance.
(Source: U.S. Department of Agriculture)
来源：美国农业部
发布：GSM·美国（发布链接）
图片来源：图：牧场上的奶牛群。美国农业部公共领域资料图（Bob Nichols 摄，编号 20130911-OC-RBN-3764），经 Wikimedia Commons，非本次检出的俄勒冈州牛群。 / Photo: A dairy cattle herd on pasture. U.S. Department of Agriculture public domain photo by Bob Nichols (20130911-OC-RBN-3764), via Wikimedia Commons; not the Oregon herd in this report.
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