Sizikova T E, Lebedev V N, Borisevich S V
FSBI «Central Scientific Research Institute No. 48» of the Ministry of Defense of Russian Federation.
Vopr Virusol. 2022 Jan 8;66(6):409-416. doi: 10.36233/0507-4088-68.
Since the Dabie bandavirus (DBV; former SFTS virus, SFTSV) was identified, the epidemics of severe fever with thrombocytopenic syndrome (SFTS) caused by this virus have occurred in several countries in East Asia. The rapid increase in incidence indicates that this infectious agent has a pandemic potential and poses an imminent global public health threat.The analysis of molecular evolution of SFTS agent that includes its variants isolated in China, Japan and South Korea was performed in this review. The evolution rate of DBV and the estimated dates of existence of the common ancestor were ascertained, and the possibility of reassortation was demonstrated.The evolutionary rates of DBV genome segments were estimated to be 2.28 × 10-4 nucleotides/site/year for S-segment, 2.42 × 10-4 for M-segment, and 1.19 × 10-4 for L-segment. The positions of positive selection were detected in the viral genome.Phylogenetic analyses showed that virus may be divided into two clades, containing six different genotypes. The structures of phylogenetic trees for S-, M- and L-segments showed that all genotypes originate from the common ancestor.Data of sequence analysis suggest that DBV use several mechanisms to maintain the high level of its genetic diversity. Understanding the phylogenetic factors that determine the virus transmission is important for assessing the epidemiological characteristics of the disease and predicting its possible outbreaks.
自大别带病毒(DBV;原发热伴血小板减少综合征病毒,SFTSV)被发现以来,由该病毒引起的发热伴血小板减少综合征(SFTS)已在东亚多个国家流行。发病率的迅速上升表明这种传染源具有大流行潜力,并对全球公共卫生构成紧迫威胁。本综述对包括在中国、日本和韩国分离出的变异株在内的SFTS病原体进行了分子进化分析。确定了DBV的进化速率和共同祖先的估计存在时间,并证明了重配的可能性。DBV基因组片段的进化速率估计为:S片段为2.28×10-4核苷酸/位点/年,M片段为2.42×10-4,L片段为1.19×10-4。在病毒基因组中检测到正选择位点。系统发育分析表明,该病毒可分为两个进化枝,包含六种不同的基因型。S、M和L片段的系统发育树结构表明,所有基因型均起源于共同祖先。序列分析数据表明,DBV利用多种机制维持其高水平的遗传多样性。了解决定病毒传播的系统发育因素对于评估该疾病的流行病学特征和预测其可能的爆发至关重要。