Sanchez-Rojas Ivan Camilo, Bonilla-Aldana D Katterine, Solarte-Jimenez Catherin Lorena, Bonilla-Aldana Jorge Luis, Acosta-España Jaime David, Rodriguez-Morales Alfonso J
Grupo de Investigación en Recursos Naturales Amazónicos GRAM, Instituto Tecnológico del Putumayo, Mocoa 860001, Colombia.
College of Medicine, Korea University, Seoul 02841, Republic of Korea.
Animals (Basel). 2025 Jul 3;15(13):1963. doi: 10.3390/ani15131963.
Highly pathogenic avian influenza (HPAI) H5N1, particularly clade 2.3.4.4b, has demonstrated an unprecedented capacity for cross-species transmission, with recent reports confirming its presence in dairy cattle in the United States of America (USA) in 2024. This unexpected spillover challenges traditional understanding of the virus's host range and raises serious public health and veterinary concerns. Infected cattle presented with clinical signs such as decreased milk production, thickened or discolored milk, respiratory issues, and lethargy. Pathological findings revealed inflammation of the mammary glands and the detection of a virus in nasal secretions and raw milk, suggesting a potential for both intra- and interspecies transmission. While the current risk of human-to-human transmission remains low, the detection of H5N1 in a human exposed to infected cattle highlights the need for heightened surveillance and protective measures. Moreover, the presence of infectious viruses in the food chain, particularly in unpasteurized milk, introduces a new dimension of zoonotic risk. This review synthesizes emerging evidence on the epidemiology, pathology, diagnostic findings, and zoonotic implications of HPAI H5N1 infection in cattle. It also highlights the importance of genomic surveillance, intersectoral collaboration, and One Health approaches in managing this evolving threat. As the virus continues to circulate and adapt across diverse hosts, including wild birds, domestic poultry, and now mammals, the potential for reassortment and emergence of novel strains remains a significant concern. Immediate actions to strengthen biosecurity, monitor viral evolution, and protect both animal and human populations are critical to mitigate the global risk posed by this expanding panzootic.
高致病性禽流感（HPAI）H5N1，尤其是2.3.4.4b分支，已展现出前所未有的跨物种传播能力，近期报告证实其于2024年在美国的奶牛中出现。这种意外的溢出事件挑战了对该病毒宿主范围的传统认知，并引发了严重的公共卫生和兽医问题。受感染的牛出现了诸如产奶量下降、牛奶变稠或变色、呼吸道问题以及嗜睡等临床症状。病理检查结果显示乳腺发炎，且在鼻分泌物和生牛奶中检测到病毒，这表明存在种内和种间传播的可能性。虽然目前人传人的风险仍然较低，但在接触受感染牛的人类中检测到H5N1凸显了加强监测和采取保护措施的必要性。此外，食物链中存在传染性病毒，尤其是在未经巴氏杀菌的牛奶中，带来了人畜共患病风险的新层面。本综述综合了关于HPAI H5N1感染牛的流行病学、病理学、诊断结果及人畜共患病影响的新证据。它还强调了基因组监测、部门间合作以及“同一健康”方法在应对这一不断演变的威胁中的重要性。随着该病毒在包括野生鸟类、家禽以及现在的哺乳动物等多种宿主中持续传播和适应，病毒重组和新毒株出现的可能性仍然是一个重大担忧。加强生物安全、监测病毒演变以及保护动物和人类群体的立即行动对于减轻这种不断扩大的动物疫病大流行所带来的全球风险至关重要。
