Garg Shikha, Reinhart Katie, Couture Alexia, Kniss Krista, Davis C Todd, Kirby Marie K, Murray Erin L, Zhu Sophie, Kraushaar Vit, Wadford Debra A, Drehoff Cara, Kohnen Allison, Owen Mackenzie, Morse Jennifer, Eckel Seth, Goswitz Jessica, Turabelidze George, Krager Steve, Unutzer Anna, Gonzales Emilio R, Abdul Hamid Cherissa, Ellington Sascha, Mellis Alexandra M, Budd Alicia, Barnes John R, Biggerstaff Matthew, Jhung Michael A, Richmond-Crum Malia, Burns Erin, Shimabukuro Tom T, Uyeki Timothy M, Dugan Vivien G, Reed Carrie, Olsen Sonja J
Influenza Division, Centers for Disease Control and Prevention, Atlanta.
California Department of Public Health, Richmond.
N Engl J Med. 2025 Feb 27;392(9):843-854. doi: 10.1056/NEJMoa2414610. Epub 2024 Dec 31.
Highly pathogenic avian influenza A(H5N1) viruses have caused widespread infections in dairy cows and poultry in the United States, with sporadic human cases. We describe characteristics of human A(H5N1) cases identified from March through October 2024 in the United States.
We analyzed data from persons with laboratory-confirmed A(H5N1) virus infection using a standardized case-report form linked to laboratory results from the Centers for Disease Control and Prevention influenza A/H5 subtyping kit.
Of 46 case patients, 20 were exposed to infected poultry, 25 were exposed to infected or presumably infected dairy cows, and 1 had no identified exposure; that patient was hospitalized with nonrespiratory symptoms, and A(H5N1) virus infection was detected through routine surveillance. Among the 45 case patients with animal exposures, the median age was 34 years, and all had mild A(H5N1) illness; none were hospitalized, and none died. A total of 42 patients (93%) had conjunctivitis, 22 (49%) had fever, and 16 (36%) had respiratory symptoms; 15 (33%) had conjunctivitis only. The median duration of illness among 16 patients with available data was 4 days (range, 1 to 8). Most patients (87%) received oseltamivir; oseltamivir was started a median of 2 days after symptom onset. No additional cases were identified among the 97 household contacts of case patients with animal exposures. The types of personal protective equipment (PPE) that were most commonly used by workers exposed to infected animals were gloves (71%), eye protection (60%), and face masks (47%).
In the cases identified to date, A(H5N1) viruses generally caused mild illness, mostly conjunctivitis, of short duration, predominantly in U.S. adults exposed to infected animals; most patients received prompt antiviral treatment. No evidence of human-to-human A(H5N1) transmission was identified. PPE use among occupationally exposed persons was suboptimal, which suggests that additional strategies are needed to reduce exposure risk. (Funded by the Centers for Disease Control and Prevention.).
高致病性甲型H5N1禽流感病毒已在美国的奶牛和家禽中广泛传播，并有散发性人类病例。我们描述了2024年3月至10月在美国确诊的人类H5N1病例的特征。
我们使用与疾病控制和预防中心甲型流感/H5亚型检测试剂盒的实验室结果相关联的标准化病例报告表，分析了实验室确诊的H5N1病毒感染患者的数据。
在46例病例患者中，20例接触过感染的家禽，25例接触过感染或疑似感染的奶牛，1例未发现接触史；该患者因非呼吸道症状住院，通过常规监测检测到H5N1病毒感染。在45例有动物接触史的病例患者中，中位年龄为34岁，所有患者的H5N1病情均较轻；无人住院，也无人死亡。共有42例患者（93%）患有结膜炎，22例（49%）发热，16例（36%）有呼吸道症状；15例（33%）仅有结膜炎。16例有可用数据的患者的中位病程为4天（范围为1至8天）。大多数患者（87%）接受了奥司他韦治疗；奥司他韦在症状出现后中位2天开始使用。在有动物接触史的病例患者的97名家庭接触者中未发现其他病例。接触感染动物的工作人员最常使用的个人防护装备（PPE）类型是手套（71%）、眼部防护（60%）和口罩（47%）。
在迄今确诊的病例中，H5N1病毒通常引起轻度疾病，主要是结膜炎，病程较短，主要发生在美国接触感染动物的成年人中；大多数患者接受了及时的抗病毒治疗。未发现H5N1人传人的证据。职业暴露人群的PPE使用情况不理想，这表明需要额外的策略来降低暴露风险。（由疾病控制和预防中心资助。）
