Department of Chronic Communicable Disease, Center for Disease Control and Prevention of Jiangsu Province, Nanjing, China.
Department of Epidemiology and Statistics, School of Public Health, Southeast University, Nanjing, China.
Front Cell Infect Microbiol. 2021 Mar 17;11:638990. doi: 10.3389/fcimb.2021.638990. eCollection 2021.
Recurrent tuberculosis (TB) is defined by more than one TB episode per patient and is caused by re-infection with a new (Mtb) strain or relapse with the previous strain. Recurrence of TB is one important obstacle for End TB strategy in the world and elucidating the triggers of recurrence is important for the current TB control strategy in China. This study aimed to analyze the sources of recurrent TB by the molecular genotyping method.
A population-based surveillance was undertaking on all culture-positive TB cases in Jiangsu province, China from 2013 to 2019. Phenotypic drug susceptibility test (DST) by proportion method and mycobacterial interspersed repetitive units-variable number of tandem repeat (MIRU-VNTR) were adopted for drug resistance and genotype detection.
A total of 1451 culture-positive TB patients were collected and 30 (2.06%, 30/1451) TB cases had recurrent TB episodes. Except 7 isolates were failed during subculture, 23 paired isolates were assessed. After genotyping by MIRU-VNTR, 12 (52.17%, 12/23) paired recurrence TB were demonstrated as relapse and 11 (47.83%,11/23) paired cases were identified as re-infection. The average interval time for recurrence was 24.04 (95%CI: 19.37-28.71) months, and there was no significant difference between relapse and re-infection. For the relapsed cases, two paired isolates exhibited drug resistance shifting, while four paired isolates revealed inconsistent drug resistance among the re-infection group including two multidrug-resistant tuberculosis (MDR-TB) at the second episode.
Relapse and re-infection contributed equally to the current situation of recurrence TB in Jiangsu, China. Besides, more efficient treatment assessment, specific and vigorous interventions are urgently needed for MDR-TB patients, considering obvious performance among re-infection cases.
复发性结核病 (TB) 是指每个患者发生超过一次 TB 发作，由新的（Mtb）菌株再感染或先前菌株复发引起。TB 的复发是全球终结 TB 战略的一个重要障碍，阐明复发的诱因对于中国当前的 TB 控制策略非常重要。本研究旨在通过分子基因分型方法分析复发性 TB 的来源。
对 2013 年至 2019 年期间中国江苏省所有培养阳性 TB 病例进行基于人群的监测。采用比例法进行表型药物敏感性试验 (DST) 和分枝杆菌插入重复单元-可变数串联重复 (MIRU-VNTR) 进行耐药性和基因型检测。
共收集了 1451 例培养阳性 TB 患者，其中 30 例（2.06%，30/1451）出现复发性 TB 发作。除 7 株在亚培养过程中失败外，还评估了 23 对分离株。通过 MIRU-VNTR 基因分型后，12 对（52.17%，12/23）复发性 TB 被证实为复发，11 对（47.83%，11/23）被确定为再感染。复发的平均间隔时间为 24.04 个月（95%CI：19.37-28.71），复发和再感染之间无显著差异。对于复发病例，两株配对分离株表现出耐药性转移，而在再感染组中，四株配对分离株显示出不一致的耐药性，包括第二次发作时有两例耐多药结核病（MDR-TB）。
在中国江苏，复发主要由复发和再感染引起。此外，鉴于再感染病例中的明显表现，迫切需要对 MDR-TB 患者进行更有效的治疗评估和具体的强化干预措施。
