贵州兴义市麻风菌株基因分型及传播链分析

目的根据麻风菌株基因型分析传播链特点。方法对2004—2009年贵州省兴义市发现的50例新发和复发麻风病患者的菌株17个串联重复序列（VNTR）位点分型，结合患者地理分布分析病例感染、传播之间的流行病学特征。结果根据AC8b、AC9、AC8a、6-7等位点基因型，兴义市流行的麻风菌有6种基因型相似的聚类株，兴义菌株在 rpoT、21-3、27-5、23-3和（GGT）5位点的拷贝数完全一致，但2号和5号聚集株在12-5位点和18-8位点的拷贝数分别是4，为兴义市所特有菌株；为聚集株的26例患者中，有7例为复发病例，21例有明确的感染传播关系；1号和4号聚类株内的15例患者（57.7%）主要分布在兴义市东南部，4号聚类株为聚集在同一自然村内的布依族患者；家内患者之间感染的菌株基因型不相同。结论兴义市多种菌株与特有菌株长期共存是兴义麻风病高流行的重要因素，具有麻风易感体质的家内成员可感染周围存在的不同菌株而发病；为阻断传播，针对家内接触者和高发乡村加强发现早期病例和进行化学预防很有必要。

Genotyping and transmission chain analysis of Mycobacterium leprae in Xingyi city,Guizhou province

ObjectiveTo explore genotypes and transmission characteristics of Mycobacterium leprae(M leprae).MethodsThe M leprae strains isolated from skin biopsies of 50 new or relapse leprosy patients during 2004 to 2009 in Xinyi city were genotyped on 17 various number tandem repeat(VNTR) loci and their transmission chains were analyzed based on epidemiologic information.ResultsThe M leprae strains were grouped into 6 clusters according to 17 alleles genotypes including AC8b,AC9,and AC8a.All the clusters had same copies on loci of rpoT,21-3,27-5,23-3,and (GGT) 5 completely.However,2nd and 5th clusters presented unique genotypes with special 4 copies on locus 12-5 and 18-8,respectively.Among 26 cluster strain infected patients,21 patients (including 7 relapses) showed clear infection transmission chain of leprosy.The 15(57.7%) patients infected by lst or 4th clusters were mainly distributed in south-east of Xingyi city.Most patients with infection of 4th cluster derived from Buyi minority patients living in a same village.Meanwhile,family patients were detected to be infected by different genotypes of M leprae.ConclusionLong coexisting of diversity and unique M leprae clusters resulted in high prevalence of leprosy in Xingyi.Family members,susceptible to leprosy,could be infected by different genotypes of M leprae in surrounding enviroment.Early patient detection and implementation of chemoprevention should be strengthened to block the transmission of leprosy among family members and villagers in high prevalent areas.