舟山市3例发热伴血小板减少综合征的病原学与遗传特征

Etiology and genetic feature of 3 cases with severe fever with thrombocytopenia syndrome in Zhoushan

目的 对舟山市3例疑似发热伴血小板减少综合征（SFTS）病例进行病原学鉴定、确诊，并分析其遗传特征。方法选用巢式RT-PCR测定新布尼亚病毒核酸及L、M、S3个特异性基因，并对基因扩增产物进行测序，测序结果与GenBank上公布的序列进行比对确认。用DNAStar软件构建进化树与序列距离表。用间接免疫荧光法测定患者恢复期和急性期血清新布尼亚病毒IgG抗体滴度。结果3例SFTS患者急性期血清中均能检测到新布尼亚病毒的3个特异性基因片段，其中S基因核苷酸序列与舟山市同类基因核苷酸序列的同源性在9414％～100．0％，患者恢复期血清病毒抗体滴度较急性期增高4倍以上。结论经过病原学鉴定，3例临床疑似患者确诊为发热伴血小板减少综合征的新近感染病例。舟山市新布尼亚病毒的遗传特征比较稳定。

Objective To identify the etiology and genetic evolution of 3 doubtful patients with severe fever with tbrombocytopenia syndrome （SFI＇S） in Zhoushan. Methods Nested RT-PCR assay was used to detect the nucleic acids and 3 specific genes （L, M, S） of novel bunyavirus. The amplification products were sequenced, then the sequencing results were compared with sequences published in GenBank. The evolutionary tree and sequence distance table were constructed by DNAStar software. IgG antibody titers of the sera in recovery phase and in acute phase of 3 patients were measured by indirect immunofluorescence assay. Results Three specific gene segments of novel bunyavirus were all detected in the sera in acute phase of 3 patients, and the homology of S gene between sequences of the gene segments and novel bunyavirus published in GenBank was 94.4%-100.0%. The antibody titers in recovery phase were 4 times more than those in acute phase. Conclusions Three clinical suspected cases are confirmed as recent infections with SFTS by etiology identification. The genetic features of novel bunyavirus in Zhoushan are stable.