Department of Laboratory Medicine and Pathology, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA.
BMC Infect Dis. 2013 Dec 5;13:571. doi: 10.1186/1471-2334-13-571.
The Philippines has an extremely high rate of tuberculosis but little is known about M. tuberculosis genotypes and transmission dynamics in this country. The aim of this study was to determine the proportion of household contacts who develop active TB due to direct transmission from an index case in that household.
Mycobacterium tuberculosis isolates from household contacts of tuberculosis patients in the Philippines were characterized using restriction-fragment-length polymorphism analysis, spoligotyping, and mycobacterial interspersed repetitive units - variable number tandem repeats typing (12-loci) to determine their utility in elucidating transmission in an area of high tuberculosis prevalence. Drug susceptibility patterns for these isolates were also determined.
Spoligotyping and MIRU-VNTR typing results matched in 10 (62.5%) of 16 index patient-household contact pairs while IS6110 fingerprints matched in only six (37.5%) pairs. Only 3/16 (18.8%) index patient-household contact pairs had identical drug susceptibility results.
Strain typing of M. tuberculosis isolates from household contacts in the Philippines indicates that transmission of strains does not necessarily occur directly from the index patient living in close proximity in the same household but rather that community-based transmission also frequently occurs. Accurate susceptibility testing of all isolates is necessary to insure optimal care of both the index patients and any culture-positive household contacts.
菲律宾的结核病发病率极高，但该国结核分枝杆菌基因型和传播动态的相关信息却很少。本研究旨在确定因直接接触家庭病例而发生活动性结核病的家庭接触者的比例。
采用限制性片段长度多态性分析、 spoligotyping 和分枝杆菌间隔重复单元 - 可变数串联重复分型（12 个位点）对来自菲律宾肺结核患者家庭接触者的结核分枝杆菌分离株进行特征分析，以确定其在高结核病流行地区阐明传播的能力。还确定了这些分离株的药物敏感性模式。
16 对索引患者-家庭接触者中，有 10 对（62.5%） spoligotyping 和 MIRU-VNTR 分型结果匹配，而只有 6 对（37.5%） IS6110 指纹图谱匹配。只有 3/16（18.8%）索引患者-家庭接触者对具有相同的药物敏感性结果。
来自菲律宾家庭接触者的结核分枝杆菌分离株的菌株分型表明，菌株的传播不一定直接来自居住在同一家庭中密切接触的索引患者，而是社区传播也经常发生。对所有分离株进行准确的药敏试验对于确保对索引患者和任何培养阳性的家庭接触者进行最佳护理是必要的。
