Torremorell M, Allerson M, Corzo C, Diaz A, Gramer M
Department of Veterinary Population Medicine, College of Veterinary Medicine, University of Minnesota, St Paul, MN 55108, USA.
Transbound Emerg Dis. 2012 Mar;59 Suppl 1:68-84. doi: 10.1111/j.1865-1682.2011.01300.x. Epub 2012 Jan 9.
Influenza A virus infections cause respiratory disease in pigs and are a risk to public health. The pig plays an important role in influenza ecology because of its ability to support replication of influenza viruses from avian, swine and human species. Influenza A virus is widespread in pigs worldwide, and influenza A virus interspecies transmission has been documented in many events. Influenza A virus is mostly transmitted through direct pig-to-pig contact and aerosols although other indirect routes of transmission may also exist. Several factors contribute to differences in the transmission dynamics within populations including among others vaccination, pig flow, animal movement and animal introduction which highlights the complexity of influenza A transmission in pigs. In addition, pigs can serve as a reservoir of influenza A viruses for other pigs and other species and understanding mechanisms of transmission within pigs and from pigs to other species and vice versa is crucial. In this paper, we review the current understanding of influenza virus transmission in pigs. We highlight the ubiquity of influenza A virus in the pig population and the widespread distribution of pandemic H1N1 virus worldwide while emphasizing an understanding of the routes of transmission and factors that contribute to virus spread and dissemination within and between pig populations. In addition, we describe transmission events between pigs and other species including people. Understanding transmission is crucial for designing effective control strategies and for making well-informed recommendations for surveillance.
甲型流感病毒感染可导致猪的呼吸道疾病，并对公共卫生构成风险。猪在流感生态学中起着重要作用，因为它能够支持来自禽类、猪类和人类的流感病毒进行复制。甲型流感病毒在全球范围内的猪群中广泛存在，并且已经记录了许多甲型流感病毒跨物种传播的事件。甲型流感病毒主要通过猪与猪之间的直接接触和气溶胶传播，不过也可能存在其他间接传播途径。包括疫苗接种、猪群流动、动物移动和动物引入等在内的几个因素导致了猪群中传播动态的差异，这凸显了猪群中甲型流感病毒传播的复杂性。此外，猪可以作为其他猪和其他物种的甲型流感病毒储存宿主，了解猪群内部以及猪与其他物种之间的传播机制（反之亦然）至关重要。在本文中，我们综述了目前对猪流感病毒传播的认识。我们强调了甲型流感病毒在猪群中的普遍存在以及大流行H1N1病毒在全球的广泛分布，同时着重阐述了对传播途径以及促成病毒在猪群内部和之间传播与扩散的因素的理解。此外，我们还描述了猪与其他物种（包括人类）之间的传播事件。了解传播对于设计有效的防控策略以及做出明智的监测建议至关重要。
