深圳市首例发热伴血小板减少综合征病例的流行病学和病原学特征研究

Analysis on the epidemiology and etiologic characteristics of first imported severe fever with thrombocytopenia syndrome case in Shenzhen

目的 对深圳市首例输入性发热伴血小板减少综合征(severe fever with thrombocytopenia syndrome, SFTS)患者进行流行病学和病原学特征研究。方法 调查分析流行病学特点,采用ELISA和荧光RT-PCR方法分别检测病毒IgM、IgG抗体和核酸,并用Vero细胞分离病毒;采用RT-PCR方法分别扩增L、S片段后进行序列测定,并与我国不同省份的发热伴血小板减少综合征布尼亚病毒(severe fever with thrombocytopenia syndrome bunyavirus, SFTSV)代表株进行同源性比较和进化树分析。结果 深圳市2017年5月报告的1起SFTS疫情为输入性病例。从患者血清标本中检测到抗体和核酸,并成功分离到SFTSV,将其命名为SFTSV-GDSZ01/2017/China。该分离株与国内SFTSV流行省份SFTSV代表株核苷酸序列有高度的同源性,L、S两个特异性基因序列相似度分别为95.3%~98.2%、93.8%~98.8%。进化树显示GDSZ01株与分离自山东泰安的SDTA3株亲缘关系最近,其次为输入地湖北省毒株,与HB29、HB154等同属于C3基因型。结论 从病原学、血清学和分子生物学特征上均证实该例SFTS输入病例是由SFTSV C3基因型引起。

Objective To study the epidemiology and the etiology characteristics of first imported severe fever with thrombocytopenia syndrome(SFTS)case reported in Shenzhen city in 2017.Methods Data on descriptive epidemiology was collected to study the characteristics to the epidemic.The serum sample collected from the suspect SFTS case was detected for IgM,IgG by ELISA and severe fever with thrombocytopenia syndrome bunyavirus(SFTSV)nucleic acid by real-time RT-PCR.The samples were further inoculated in Vero cell for virus isolation.The partial fragements of L and S gene were amplified by RT-PCR and sequenced to construct homology comparison and phylogenetic tree with the strains isolated from other areas.Results The case was laboratory confirmed imported SFTS case in Shenzhen on May 2017.IgM antibody and RNA of SFTSV were detected in the serum sample.SFTSV named GDSZ01/2017/China was successfully isolated from the serum sample.The high nucleotide homology of L and S genome segments were found at 95.3%-98.2%and 93.8%-98.8%with other representative strains from the popular provinces,respectively.The phylogenetic tree indicated that GDSZ01 was most close to SDTA_3 strain,next to strains in Hubei procince.The isolated SFTSV belonged to genotype C3 with HB29,HB154.Conclusions The virological,serological and molecular features showed that the imported case of SFTS in 2017 was caused by SFTSV C3 genotype.