大连市“蜱咬”患者新布尼亚病毒(SFTSV)的检测分析

目的 通过对大连市一起“蜱咬”患者流行病学调查及病原体检测,探讨新布尼亚病毒(Severe fever with thrombocytopenia syndrome bunyavirus, SFTSV)在辽宁省南部沿海地区的流行范围。方法 采用ELISA方法对“蜱咬”患者急性期血清样本及同居住地的26份非患者血清样本进行SFTSV的IgM、IgG抗体检测;采用实时荧光定量RT-PCR方法检测“蜱咬”患者血液样本SFTSV核酸;采用VERO-E6细胞对“蜱咬”患者血液样本进行病毒分离并鉴定。结果 “蜱咬”患者急性期血清样本SFTSV的IgM抗体阳性、IgG抗体阴性;26份非患者血清样本中4份SFTSV的IgG抗体阳性;“蜱咬”患者血液样本SFTSV核酸阳性;从“蜱咬”患者血液样本和体表叮咬的蜱虫中各分离出1株病毒,经SFTSV的M片段全基因测序引物测序鉴定为SFTSV。结论 “蜱咬”患者血液分离株与蜱虫分离株均为SFTSV,同源性达99.7%,该病毒是导致患者发病的重要原因。本次分离到的2株病毒与我省东部(丹东、抚顺),北部(铁岭)山区分离株遗传距离相对较远。SFTSV在正常人群中存在隐性感染者。

Detection and analysis on severe fever with thrombocytopenia syndrome bunyavirus in blood from a patient bitted by tick in Dalian City

The epidemic rang of SFTSV (severe fever with thrombocytopenia syndrome bunyavirus) in southern coastland of Liaoning was discussed by pathogen detecting of blood sample and epidemiological survey of the patient bitted by tick in Dalian. The IgM and IgG of SFTSV in serum from the patient in acute phase and 26 local people who were not bitted by tick were detected by ELISA. The nucleic acid of SFTSV was tested by RT-PCR, and the viral isolation and identification of the blood sample from the patient were conducted by VERO-E6 cell. The result showed that IgM antibodies of SFTSV from serum in acute phase were positive while the IgG was negative, but that of another 4 samples in 26 healthy people were positive. The PCR result of serum from patient was positive. One positive virus strain was isolated from the blood sample of the patient and one was from the tick that bitted people’s skin. Then they were identified as SFTSV by detecting the M section of genome with whole gene sequencing primer. The strains isolated from patient and tick were both SFTSV and the homology of them was more than 99%, which showed that SFTSV was an important pathogen. The genetic distance between the virus isolated in Dandong, Fushun and Tieling and that isolated in this case was relatively far from each other, which suggested that the latent infection of SFTSV also existed in health people in Dalian City.