Martínez-Avilés Marta, Iglesias Irene, De La Torre Ana
Centro de Investigación en Sanidad Animal (CISA), INIA, Valdeolmos, Spain.
Front Vet Sci. 2020 Apr 1;7:155. doi: 10.3389/fvets.2020.00155. eCollection 2020.
African swine fever (ASF) is one of the most important emerging transboundary diseases of pigs, causing trade restrictions, and a health impact on susceptible pigs. Nine countries in the continental European Union (Estonia, Lithuania, Latvia, Poland, Czech Republic, Bulgaria, Belgium, Romania, and Hungary) have been affected by ASF from 2014 to 2018 and it keeps spreading despite the efforts to control it. For a number of years, we have witnessed high case-fatality rates in wild boar found dead particularly in new infected areas, which is typical of the peracute and acute forms of the infection at the beginning of an ASF epidemic. Experimental evidence with currently circulating strains indicates that some infected animals can remain asymptomatic and might even survive the infection. An increased presence of virus of moderate virulence can complicate ASF diagnosis as well as the mitigation and control of the disease. We analyze the ASF surveillance data in wild boar in the four EU countries where ASF has been present for longer, comparing the spatial density of antibody positive notifications with the time ASF has been present per region. Results indicate an increasing annual distribution of notifications based on antibodies over nucleic acid detection in hunted wild boar in Estonia, Latvia and Poland. Potentially, Lithuania, and Poland seem to have experienced more acute forms in 2017 and 2018 than Latvia and Estonia. Overall there was a positive statistical correlation between time with infection (TWI) and antibody positive density, with some variations in certain regions, particularly of Lithuania and Estonia. The increasing trend in potential survivors (hunted wild boar with confirmed PCR negative and antibody positive results) enhances the importance of surveillance design to sample and test shot wild boar. In conclusion, surveillance data based on ASFV detection by PCR and serology can be used to assess the status of the epidemic in wild boar.
非洲猪瘟（ASF）是猪最重要的新出现的跨界疾病之一，会导致贸易限制，并对易感猪产生健康影响。2014年至2018年期间，欧盟大陆的9个国家（爱沙尼亚、立陶宛、拉脱维亚、波兰、捷克共和国、保加利亚、比利时、罗马尼亚和匈牙利）受到了非洲猪瘟的影响，尽管采取了控制措施，但疫情仍在蔓延。多年来，我们目睹了在新感染地区发现的野猪的高死亡率，这是非洲猪瘟疫情开始时急性和超急性感染形式的典型特征。目前流行毒株的实验证据表明，一些感染动物可能没有症状，甚至可能在感染后存活下来。中等毒力病毒的出现增加会使非洲猪瘟的诊断以及疾病的缓解和控制变得复杂。我们分析了四个非洲猪瘟流行时间较长的欧盟国家野猪的监测数据，比较了抗体阳性报告的空间密度与每个地区非洲猪瘟出现的时间。结果表明，在爱沙尼亚、拉脱维亚和波兰，基于抗体的报告年度分布相对于猎捕野猪的核酸检测呈上升趋势。2017年和2018年，立陶宛和波兰可能比拉脱维亚和爱沙尼亚经历了更急性的感染形式。总体而言，感染时间（TWI）与抗体阳性密度之间存在正相关统计关系，某些地区存在一些差异，特别是立陶宛和爱沙尼亚。潜在幸存者（经PCR确认阴性且抗体阳性的猎捕野猪）数量的增加趋势凸显了监测设计对猎捕野猪进行采样和检测的重要性。总之，基于PCR和血清学检测非洲猪瘟病毒的监测数据可用于评估野猪疫情的状况。
