Vilem Annika, Nurmoja Imbi, Niine Tarmo, Riit Taavi, Nieto Raquel, Viltrop Arvo, Gallardo Carmina
Institute of Veterinary Medicine and Animal Sciences, Estonian University of Life Sciences, Kreutzwaldi 62, 51006 Tartu, Estonia.
Veterinary and Food Laboratory, Kreutzwaldi 30, 51006 Tartu, Estonia.
Pathogens. 2020 Jul 17;9(7):582. doi: 10.3390/pathogens9070582.
After the extensive spread of the African swine fever virus (ASFV) genotype II in Eastern Europe, the first case of African swine fever (ASF) in Estonia was diagnosed in September 2014. By the end of 2019, 3971 ASFV-positive wild boars were found, and 27 domestic pig outbreaks were reported. A selection of ASFV isolates from wild boar and domestic pigs (during the period of September 2014-2019) was molecularly characterized using standardized genotyping procedures. One of the proven markers to characterize this virus is the central variable region (CVR) within the gene. In summer 2015, a new ASFV genotype II CVR variant 2 (GII-CVR2) was confirmed in Estonia. The results suggest that the GII-CVR2 variant was only confirmed in wild boar from a limited area in southern Estonia in 2015 and 2016. In addition to GII-CVR2, a single nucleotide polymorphism (SNP) that resulted in amino acid change was identified within the genotype II CVR variant 1 (GII-CVR1). The GII-CVR1/SNP1 strain was isolated in Estonia in November 2016. Additional GII-CVR1/SNP1 cases were confirmed in two neighbouring counties, as well as in one outbreak farm in June 2017. Based on the available data, no GII-CVR2 and GII-CVR1/SNP1 have been reported by other affected European countries. The spread of variant strains in Estonia has been limited over time, and restricted to a relatively small area.
非洲猪瘟病毒（ASFV）基因型II在东欧广泛传播后，爱沙尼亚于2014年9月确诊首例非洲猪瘟（ASF）病例。截至2019年底，共发现3971头ASFV呈阳性的野猪，报告了27起家猪疫情。采用标准化基因分型程序，对2014年9月至2019年期间从野猪和家猪中选取的ASFV分离株进行了分子特征分析。表征该病毒的一个已证实的标记是 基因内的中央可变区（CVR）。2015年夏季，爱沙尼亚确认了一种新的ASFV基因型II CVR变体2（GII-CVR2）。结果表明，GII-CVR2变体仅在2015年和2016年于爱沙尼亚南部一个有限区域的野猪中得到确认。除GII-CVR2外，在基因型II CVR变体1（GII-CVR1）内还鉴定出一个导致氨基酸变化的单核苷酸多态性（SNP）。GII-CVR1/SNP1毒株于2016年11月在爱沙尼亚分离得到。2017年6月，在两个相邻县以及一个疫情农场又确认了更多GII-CVR1/SNP1病例。根据现有数据，其他受影响的欧洲国家尚未报告GII-CVR2和GII-CVR1/SNP1。随着时间推移，变异毒株在爱沙尼亚的传播一直有限，且局限于一个相对较小的区域。
