俄勒冈州莫罗县奶牛场确诊首例禽流感 成全美第22个出现奶牛感染的州
俄勒冈州农业厅与美国农业部动植物卫生检验局确认，莫罗县一处商业奶牛场检出高致病性禽流感，这是俄勒冈州奶牛群的首例感染，使俄勒冈成为全美第22个出现奶牛感染的州。
感染是在俄勒冈州常规监测中发现的，该牛群此前多轮检测均为阴性，牛奶样本经联邦国家兽医服务实验室聚合酶链式反应检测，确认为H5分支2.3.4.4b毒株。目前这处奶牛场已被州政府隔离，限制牛只流动，以防病毒进一步传播。官方强调，商业巴氏杀菌牛奶仍然安全，消费者无需担忧。
俄勒冈是自10月初以来第三个此前未受影响、如今确认奶牛感染禽流感的州。华盛顿州于10月8日确认首例，此后感染牛群已增至40多个；印第安纳州于11月2日确认首例。自2024年3月多州疫情暴发以来，禽流感已在全美奶牛群中持续扩散，农业部门呼吁养殖户加强生物安全措施并及时上报异常情况。
Oregon Confirms First Bird Flu Case in Dairy Cattle in Morrow County, Becoming the 22nd Affected State
The Oregon Department of Agriculture and the USDA's Animal and Plant Health Inspection Service have confirmed a detection of highly pathogenic avian influenza at a commercial dairy in Morrow County, the first infection in an Oregon dairy herd, making Oregon the 22nd U.S. state with bird flu in dairy cattle.
The infection was found through Oregon's routine surveillance; the herd had tested negative in multiple earlier rounds. Milk samples were confirmed by PCR testing at the federal National Veterinary Services Laboratories as H5 clade 2.3.4.4b. The dairy has been placed under state quarantine restricting cattle movement to prevent further spread. Officials stressed that commercial pasteurized milk remains safe and consumers need not worry.
Oregon is the third previously unaffected state to confirm dairy cattle infections since early October. Washington confirmed its first case on October 8 and its infected herds have since grown to more than 40; Indiana confirmed its first case on November 2. Since the multistate outbreak began in March 2024, bird flu has continued to spread through U.S. dairy herds, and agriculture officials are urging producers to strengthen biosecurity and report abnormalities promptly.
来源：俄勒冈州农业厅
发布：GSM·美国（发布链接）
图片来源：牧场上的奶牛。图：Angela Marie／Wikimedia Commons，CC BY 2.0授权 / A dairy cow on pasture. Photo: Angela Marie / Wikimedia Commons, CC BY 2.0
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