间接免疫荧光法在健康人群新布尼亚病毒抗体检测中的应用

目的探讨间接免疫荧光法（IFA）对急性发热伴血小板减少综合征布尼亚病毒（SVTSV）感染的诊断价值，并了解宁波市象山县SFTSV流行区健康人群的抗体水平。方法非洲绿猴肾细胞（Vero细胞）分离的本地SYTSV株制作抗原片，以IFA法和EUSA法对象山县265份健康人群血清进行SFTSV抗体测定，并用病毒微量中和试验（MNT）验证两种方法的检测效果。结果265份象山县健康人群血清中，IgG抗体经IFA法检测共36份阳性，阳性率为13．58％（36／265）；经ELISA法检测，共23份阳性，阳性率为8．68％（23／265）；两者差异有统计学意义（X^2=9．624，P〈0．05）。与MNT法检出结果对比，IFA法诊断的符合率为89．19（33／37），而ELISA法的符合率为70．27％（26／37）；两者比较差异有统计学意义（X^2=4．097，P〈0．05）。所有SFTSV—IgG阳性样本中SFTSV—IgM同时阳性共23份，占62．16％（23／37）。结论IFA法可同时检测SFTSV—IgG和-IgM抗体，可作为未在病毒血症期内就症病例的补充诊断方法，也适合对人群抗体水平的调查。宁波市象山县健康人群中检出较高水平的SFTSV-IgG抗体，表明存在SFTSV的流行以及隐性感染；SFTSV—IgM阳性提示这些感染为新近感染。

Indirect immunofluorescent assay for detection of antibodies of severe fever with thrombocytopenia syndrome bunyavirus in healthy population

Objective To explore the early diagnostic value of indirect immunofluorescence assay （IFA） in detection of severe fever with thrombocytopenia syndrome bunyavirus （SFTSV） , and to have an overview on the level of antibody against SFFSV in healthy population of Ningbo Xiangshan. Methods Local SFFSV strains isolated from African green monkey kidney cells （Vero cells） were used to produce antigen films. SFTSV antibody in blood samples from 265 healthy individuals in Xiangshan were detected by IFA and ELISA. The results of IFA and ELISA were compared with that of micro-neutralization test （MNT）. Results Of 265 serum samples, the positive rates of SFISV-IgG detected by IFA and ELISA were 13.58% （36/256） and 8.68% （23/256） ,respectively, with a significant difference 0（2=9.624,P〈0.05）. The coincidence rate of MNT and IFA was 89.19% （33/37） which was higher than 70.27% （26/37） of MNT and ELISA , with a significant difference between them 0（2=4.097, P〈0.05 ）. Both of IgM and IgG were detected positive in 23 samples, accounting for 62.16% （23/37） of IgG positive samples. Conclusions IFA can be used as a complementary method for diagnosis of SFTSV infection when viremia is absent because of its ability to detect IgM and IgG together. IFA is also suitable for antibody detection. High level of SFTSV-IgG antibody in healthy population of Ningbo Xiangshan suggests the epidemic and latent infection of SFFSV in local area. SFTSV-IgM detected positive in healthy individuals means the possibility of new infection in recent years.