State Key Laboratory of Emerging Infectious Diseases & Department of Microbiology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, 21 Sassoon Road, Pokfulam, Hong Kong, China.
Nature. 2011 May 26;473(7348):519-22. doi: 10.1038/nature10004.
Swine influenza A viruses (SwIV) cause significant economic losses in animal husbandry as well as instances of human disease and occasionally give rise to human pandemics, including that caused by the H1N1/2009 virus. The lack of systematic and longitudinal influenza surveillance in pigs has hampered attempts to reconstruct the origins of this pandemic. Most existing swine data were derived from opportunistic samples collected from diseased pigs in disparate geographical regions, not from prospective studies in defined locations, hence the evolutionary and transmission dynamics of SwIV are poorly understood. Here we quantify the epidemiological, genetic and antigenic dynamics of SwIV in Hong Kong using a data set of more than 650 SwIV isolates and more than 800 swine sera from 12 years of systematic surveillance in this region, supplemented with data stretching back 34 years. Intercontinental virus movement has led to reassortment and lineage replacement, creating an antigenically and genetically diverse virus population whose dynamics are quantitatively different from those previously observed for human influenza viruses. Our findings indicate that increased antigenic drift is associated with reassortment events and offer insights into the emergence of influenza viruses with epidemic potential in swine and humans.
猪流感病毒（SwIV）在畜牧业中造成了重大的经济损失，也导致了人类疾病的发生，偶尔还会引发人类大流行，包括 2009 年 H1N1 病毒引发的大流行。由于缺乏对猪流感的系统和纵向监测，我们难以重建这种大流行的起源。大多数现有的猪流感数据来自在不同地理区域从患病猪中收集的机会性样本，而不是在特定地点进行的前瞻性研究，因此，我们对 SwIV 的进化和传播动态了解甚少。在这里，我们利用香港超过 650 株 SwIV 分离株和超过 800 份来自该地区 12 年系统监测的猪血清的数据集，以及回溯 34 年的数据，定量描述了 SwIV 在香港的流行病学、遗传和抗原动态。洲际病毒传播导致了重配和谱系更替，产生了具有不同抗原性和遗传多样性的病毒群体，其动态与之前观察到的人类流感病毒明显不同。我们的研究结果表明，抗原漂移的增加与重配事件有关，并为猪流感和人类中具有流行潜力的流感病毒的出现提供了深入的见解。
