背景:尽管有全球结核病(TB)干预措施,这种疾病仍然是主要的公共卫生问题之一。肯尼亚在全球22个高负担结核病国家中排名第15位。
方法:在肯尼亚西部进行了一项横断面研究,由10个县组成。使用了多阶段抽样方法,其中随机选择一个县,然后从每个县抽取两个高容量的医疗机构。通过与SITVIT数据库进行比较,可以确定spoligotype概况及其家族分布和谱系水平。
结果:谱系分布模式显示,最主要的谱系是CAS220(39.8%),其次是北京128(23.1%)。确定的其他谱系是T,LAM,H,X,S和MANU被量化为87(15.7%),67(12.1%),16(2.8%),10(1.8%),8(1.4%)和5(0.9%)。在HIV阴性和阳性结核病患者中,CAS和北京菌株是最主要的谱系。与野生型相比,北京谱系在耐药结核分枝杆菌菌株中也是最主要的。共有12个(2.0%)是孤儿结核分枝杆菌菌株,分布在研究地点的所有10个县。在调整潜在联合创始人的多变量逻辑回归中,三个潜在危险因素是显著的。HIV感染状况(OR=1.52,CI=0.29-3.68,P值为0.001),饮酒(OR=0.59,CI=0.43-3.12,P值=0.001)和跨境旅行(OR=0.61,CI=0.49-3.87,P值=0.026)。大多数结核分枝杆菌临床分离株显示遗传聚类,多变量逻辑回归表明聚类的三个潜在风险因素。HIV感染状况(OR=1.52,CI=0.29-3.68,P值为0.001),饮酒(OR=0.59,CI=0.43-3.12,P值=0.001)和跨境旅行(OR=0.61,CI=0.49-3.87,P值=0.026)。
结论:肯尼亚西部10个县存在不同的结核分枝杆菌菌株。聚集基因型的主要分布表明,该地区的大多数结核病病例是由于潜伏结核病激活以外的不良传播所致。
BACKGROUND: Despite global tuberculosis (TB) interventions, the disease remains one of the major public health concerns. Kenya is ranked 15th among 22 high burden TB countries globally.
METHODS: A cross-sectional study was conducted in Western Kenya, which comprises 10 counties. A multistage sampling method was used where a single sub-county was randomly selected followed by sampling two high volume health facility from each sub-county. Identification of spoligotype profiles and their family distribution and lineage level were achieved by comparison with SITVIT database.
RESULTS: Lineage distribution pattern revealed that the most predominant lineage was CAS 220 (39.8%) followed by Beijing 128 (23.1%). The other lineages identified were T, LAM, H, X, S and MANU which were quantified as 87 (15.7%), 67 (12.1%), 16 (2.8%), 10 (1.8%), 8 (1.4%) and 5 (0.9%) respectively. CAS and Beijing strains were the most predominant lineage in both HIV negative and positive TB patients. The Beijing lineage was also the most predominant in resistant M. tuberculosis strains as compared to wild type. A total of 12 (2.0%) were orphaned M. tuberculosis strains which were spread across all the 10 counties of the study site. In multivariate logistic regression adjusting for potential cofounders three potential risk factors were significant. HIV status (OR = 1.52, CI = 0.29-3.68 and P value of 0.001), Alcohol use (OR = 0.59, CI = 0.43-3.12 and P-value =0.001) and cross border travel (OR = 0.61, CI = 0.49-3.87 and P value = 0.026). Most M. tuberculosis clinical isolates showed genetic clustering with multivariate logistic regression indicating three potential risk factors to clustering. HIV status (OR = 1.52, CI = 0.29-3.68 and P value of 0.001), Alcohol use (OR = 0.59, CI = 0.43-3.12 and P-value =0.001) and cross border travel (OR = 0.61, CI = 0.49-3.87 and P value = 0.026).
CONCLUSIONS: There exist diverse strains of M. tuberculosis across the 10 counties of Western Kenya. Predominant distribution of clustered genotype points to the fact that most TB cases in this region are as a result of resent transmission other than activation of latent TB.