Continued low rates of transmission of Mycobacterium tuberculosis in Norway
Continued low rates of transmission of Mycobacterium tuberculosis in Norway
复制标题
DOI：
10.1128/jcm.41.7.2968-2973.2003
复制
发表时间：
2003-07-01
影响因子：
9.4
通讯作者：
Caugant, DA
中科院分区：
文献类型：
--
作者：
Dahle, UR;Sandven, P;Caugant, DA
在这项研究中，我们确定了1999年至2001年在挪威分离的结核分枝杆菌的遗传多样性。结果进行了比较，从1994年至1998年分离的菌株。在过去3年期间，共有818名患者被诊断患有结核病（TB）。在这些病例中，576例（70%）通过培养进行了验证，551例（96%）患者的菌株通过IS 6110限制性片段长度多态性（RFLP）方法进行了分析。我们从分析中排除了13种菌株（2.4%），因为发现它们代表假阳性样本。共67株（12%）进行了分析，少于5个拷贝的IS 6110的spoligotyping。这些菌株来自157名挪威患者（29%）和381名外国患者（71%）。1994 ~ 1998年各菌株间的多样性为87%，而1994 ~ 1998年各菌株间的多样性为90%。集群被认为是由最近的传播引起的;这种传播的程度在1999年至2001年为10%，而在整个8年期间（1994年至2001年），它是11%。在1999年至2001年被诊断为集群的109名患者中，有89人感染了携带超过4个IS 6110拷贝的菌株。在这89名患者中，有52名（58%）感染了1994年至1998年已经确定的菌株。结果表明，挪威的大多数结核病病例是由于新菌株的输入，而不是由于国内传播。这一发现表明，需要改进对抵达挪威的移民进行结核病筛查的工作。然而，疫情主要是由在挪威流行多年的菌株引起的。
In this study, we determined the genetic diversity of Mycobacterium tuberculosis isolated in Norway from 1999 to 2001. The results were compared to those for strains isolated from 1994 to 1998. A total of 818 patients were diagnosed with tuberculosis (TB) during the last 3-year period. Of these cases, 576 (70%) were verified by culturing, and strains from 551 patients (96%) were analyzed by the IS6110 restriction fragment length polymorphism (RFLP) method. We excluded 13 strains (2.4%) from the analyses, since they were found to represent false-positive samples. A total of 67 strains (12%) that carried fewer than five copies of IS6110 were analyzed by spoligotyping. The strains were from 157 patients (29%) of Norwegian origin and 381 patients (71%) of foreign origin. The rate of diversity among all of the strains was 90%, while in 1994 to 1998 it was 87%. Clusters were assumed to have arisen from recent transmission; the degree of such transmission was 10% in 1999 to 2001, while for the whole 8-year period (1994 to 2001), it was 11%. Of the 109 patients diagnosed as being part of a cluster in 1999 to 2001, 89 were infected with a strain that carried more than four copies of IS6110. Among these 89 patients, 52 (58%) were infected with a strain that had already been identified in 1994 to 1998. The results indicated that most cases of TB in Norway were due to the import of new strains rather than to transmission within the country. This finding demonstrates that screening of immigrants for TB upon arrival in Norway needs to be improved. Outbreaks, however, were caused mainly by strains that have been circulating in Norway for many years.