天津地区2013年百日咳感染状况及分子流行病学特征分析

The status of pertussis infection and molecular epidemiological characteristics of pertussis in Tianjin, 2013

目的 了解2013年天津地区百日咳感染状况及分子流行病学特点.方法 选取天津地区监测点181例百日咳疑似病例作为研究对象,采集鼻咽拭子和血清标本,应用Real-timePCR检测百日咳鲍特菌双目标基因,同时采用ELISA检测其特异性百日咳毒素IgG （PT-IgG）.30份百日咳DNA阳性标本应用PCR扩增菌毛蛋白2（FIM2）、菌毛蛋白3（FIM3）基因,并对PCR产物进行DNA测序分析.结果 148例百日咳病例Real-time PCR检测阳性率为68.24％;108例PT-IgG检测阳性率为55.56％.101例核酸阳性病例的病程中位数为11 d;60例PT-IgG阳性病例的病程M为21d.＜l岁病例的Real-time PCR检测阳性率为84.28％,与其他年龄段阳性率比较差异有统计学意义.30份标本百日咳鲍特菌基因核苷酸同源性为99.6％～100.0％,与GenBank中国际标准株TohamaI、中国疫苗株同源性为99％.结论 2013年天津地区流行的百日咳鲍特菌与国际标准株及中国疫苗株亲缘关系较近,＜1岁病例Real-time PCR检测阳性率高于其他年龄段.

Objective To understand the status of pertussis infection and characteristics of molecular epidemiology of pertussis in 2013 in Tianjin.Methods Totally,181 suspected pertussis cases were selected and their nasopharyngeal swabs and serum were sampled at the Disease Monitoring Settings in Tianjin.Real-time PCR was used to detect Bordetella pertussis double target genes and enzyme linked immune-sorbent assay （ELISA） method was used to detect the specific pertussis toxin IgG （PT-IgG） antibody.Fimbriae 2 （FIM2） and Fimbriae 3 （FIM3） genes of pertussis was amplified by PCR for sequencing,from 30 pertussis DNA positive samples.Results The positive rate of Real-time PCR was 68.24％ in 148 cases and the positive rate of PT-IgG antibody was 55.56％ in 108 cases.Among 101 cases that nucleic acid were positive,the median duration of disease was 11 days.Among the PT-IgG Positive cases （60 cases）,the median duration of disease was 21 days.In cases under 1 year old,the Real-time PCR testing positive rate was 84.28％.Positive rates among other age groups,the differences were statistically significant.Nucleotide homologies of FIM2 and FIM3 genes from 30 pertussis strains were 99.6％-100.0％,while it was 99％ when compared to both international standard Tohama strain and Chinese vaccine strain.Conclusion Detection of pertussis by Real-time PCR from clinical nasopharyngeal swab sample was quick and sensitive for the diagnosis.Bordetella pertussis epidemic strains in Tianjin area appeared close relation with both the international standards and China vaccine strains.