Banu Sayera, Rahman Md Toufiq, Uddin Mohammad Khaja Mafij, Khatun Razia, Khan Md Siddiqur Rahman, Rahman Md Mojibur, Uddin Syed Iftekhar, Ahmed Tahmeed, Heffelfinger James D
International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh.
National TB Control Program, Directorate General of Health Services, Mohakhali, Dhaka, Bangladesh.
PLoS One. 2015 May 1;10(5):e0124976. doi: 10.1371/journal.pone.0124976. eCollection 2015.
Understanding tuberculosis (TB) transmission dynamics is essential for establishing effective TB control strategies in settings where the burden and risk of transmission are high. The objectives of this study were to evaluate the effect of active screening on controlling TB transmission and also to characterize Mycobacterium tuberculosis strains for investigating transmission dynamics in a correctional setting.
The study was carried out in Dhaka Central Jail (DCJ), from October 2005 to February 2010. An active case finding strategy for pulmonary TB was established both at the entry point to the prison and inside the prison. Three sputum specimens were collected from all pulmonary TB suspects and subjected to smear microscopy, culture, and drug susceptibility testing as well as genotyping which included deletion analysis, spoligotyping and analysis of mycobacterial interspersed repetitive units (MIRU).
A total of 60,585 inmates were screened during the study period. We found 466 inmates with pulmonary TB of whom 357 (77%) had positive smear microscopy results and 109 (23%) had negative smear microscopy results but had positive results on culture. The number of pulmonary TB cases declined significantly, from 49 cases during the first quarter to 8 cases in the final quarter of the study period (p=0.001). Deletion analysis identified all isolates as M. tuberculosis and further identified 229 (70%) strains as 'modern' and 100 (30%) strains as 'ancestral'. Analysis of MIRU showed that 347 strains (85%) exhibited unique patterns, whereas 61 strains (15%) clustered into 22 groups. The largest cluster comprised eight strains of the Beijing M. tuberculosis type. The rate of recent transmission was estimated to be 9.6%.
Implementation of active screening for TB was associated with a decline in TB cases in DCJ. Implementation of active screening in prison settings might substantially reduce the national burden of TB in Bangladesh.
了解结核病（TB）传播动态对于在结核病负担和传播风险较高的环境中制定有效的结核病控制策略至关重要。本研究的目的是评估主动筛查对控制结核病传播的效果，并对结核分枝杆菌菌株进行特征分析，以研究惩教机构中的传播动态。
该研究于2005年10月至2010年2月在达卡中央监狱（DCJ）开展。在监狱入口处和监狱内部均建立了针对肺结核的主动病例发现策略。从所有肺结核疑似患者中采集三份痰标本，进行涂片显微镜检查、培养、药敏试验以及基因分型，基因分型包括缺失分析、间隔寡核苷酸分型（spoligotyping）和分枝杆菌插入重复单元（MIRU）分析。
在研究期间共筛查了60585名囚犯。我们发现466名患有肺结核的囚犯，其中357名（77%）涂片显微镜检查结果呈阳性，109名（23%）涂片显微镜检查结果呈阴性，但培养结果呈阳性。肺结核病例数显著下降，从研究期间第一季度的49例降至最后一季度的8例（p = 0.001）。缺失分析确定所有分离株均为结核分枝杆菌，并进一步确定229株（70%）为“现代型”菌株，100株（3
