Brito Barbara, König Guido, Cabanne Gustavo Sebastian, Beascoechea Claudia Perez, Rodriguez Luis, Perez Andres
USDA/ARS Foreign Animal Disease Research Unit, Plum Island Animal Disease Center, P.O. Box 848, Greenport, NY 11944, USA.
Instituto de Biotecnología, INTA, Buenos Aires, Argentina.
Infect Genet Evol. 2016 Jul;41:93-99. doi: 10.1016/j.meegid.2016.03.026. Epub 2016 Apr 10.
Foot-and-mouth disease (FMD) is a highly transmissible disease of hooved livestock. Although FMD has been eradicated from many countries, economic and social consequences of FMD reintroductions are devastating. After achieving disease eradication, Argentina was affected by a major epidemic in 2000-2002, and within few months, FMD virus spread throughout most of the country and affected >2500 herds. Available records and viral strains allowed us to assess the origins, spread and progression of this FMD epidemic, which remained uncertain. We used whole genome viral sequences and a continuous phylogeographic diffusion approach, which revealed that the viruses that caused the outbreaks spread fast in different directions from a central area in Argentina. The analysis also suggests that the virus that caused the outbreaks in the year 2000 was different from those found during the 2001 epidemic. To estimate if the approximate overall genetic diversity of the virus was related to disease transmission, we reconstructed the viral demographic variation in time using Bayesian Skygrid approach and compared it with the epidemic curve and the within-herd transmission rate and showed that the genetic temporal diversity of the virus was associated with the increasing number of outbreaks in the exponential phase of the epidemic. Results here provide new evidence of how the disease entered and spread throughout the country. We further demonstrate that genetic data collected during a FMD epidemic can be informative indicators of the progression of an ongoing epidemic.
口蹄疫（FMD）是一种在有蹄类牲畜中具有高度传染性的疾病。尽管许多国家已根除口蹄疫，但口蹄疫重新传入所带来的经济和社会后果却是毁灭性的。在实现疾病根除后，阿根廷在2000 - 2002年受到了一场重大疫情的影响，在短短几个月内，口蹄疫病毒蔓延至该国大部分地区，影响了超过250个畜群。现有记录和病毒株使我们能够评估这场口蹄疫疫情的起源、传播和发展情况，而这些情况此前一直不明朗。我们使用了全基因组病毒序列和一种连续的系统地理学扩散方法，结果显示引发疫情的病毒从阿根廷的一个中心区域向不同方向迅速传播。分析还表明，2000年引发疫情的病毒与2001年疫情期间发现的病毒不同。为了评估病毒的总体遗传多样性是否与疾病传播有关，我们使用贝叶斯Skygrid方法重建了病毒随时间的种群动态变化，并将其与疫情曲线以及畜群内传播率进行比较，结果表明病毒的遗传时间多样性与疫情指数增长阶段疫情爆发数量的增加有关。这里的结果为该疾病如何传入并在全国传播提供了新的证据。我们进一步证明，在口蹄疫疫情期间收集的遗传数据可以成为正在发生的疫情发展情况的信息性指标。
