Grupo MICOBAC-UN, Departamento de Microbiología, Facultad de Medicina, Universidad Nacional de Colombia, Bogotá DC, Colombia.
Programa de Tuberculosis y Lepra, Secretaría de Salud de Cundinamarca, Bogotá DC, Colombia.
PLoS One. 2019 Jan 25;14(1):e0209895. doi: 10.1371/journal.pone.0209895. eCollection 2019.
Active tuberculosis (TB) and latent tuberculosis infection (LTBI) are a public health threat in prisons around the world. The objectives of the study were to estimate the prevalence of LTBI and TB as well as to investigate TB transmission inside one prison, in Colombia.
A Cross-sectional study was conducted in inmates who agreed to participate. Inmates with respiratory symptoms (RS) of any duration underwent to medical evaluation and three sputum samples were taken for smear microscopy and culture for TB diagnosis. Drug susceptibility was analyzed using BACTEC MGIT 960 and GenoType MTBDRplus. Molecular genotyping of Mycobacterium tuberculosis isolates was performed by 24-Locus MIRU-VNTR and spoligotyping. LTBI was evaluated according to the result of the tuberculin skin test (TST). Close contact investigation was conducted inside the prison for inmates that shared the cell with the index TB case.
Among 301/2,020 (15%) inmates with RS of any duration, 8% were diagnosed with active TB. The prevalence of active TB was 1,026 cases/100,000 inmates. We isolated M. tuberculosis in 19/24 (79%) TB cases, 94.7% were susceptible to first line drugs and only one was monoresistant to isoniazid. The most prevalent sub-lineage was Haarlem (68.4%), followed by LAM (26.3%) and T superfamily (5.3%). 24-Locus MIRU-VNTR typing results alone or in combination with spoligotyping identified three clusters containing two isolates each. Two clusters corresponded to inmates that shared the same cell, but each one was located in different blocks of the prison. Inmates from the last cluster were in the same block in nearby cells. TST reading was performed in 95.6% inmates, and 67.6% had a positive reaction.
The prevalence of LTBI and TB was higher in prison than in the general population. Molecular genotyping suggests that TB in this prison is mainly caused by strains imported by inmates or endogenous reactivation.
活动性肺结核（TB）和潜伏性结核感染（LTBI）是全球监狱中的公共卫生威胁。本研究的目的是估计 LTBI 和 TB 的流行率，并调查哥伦比亚一所监狱内的 TB 传播情况。
对同意参与的囚犯进行横断面研究。有任何持续时间呼吸道症状（RS）的囚犯接受医学评估，并采集三份痰样进行涂片显微镜检查和培养以诊断 TB。使用 BACTEC MGIT 960 和 GenoType MTBDRplus 分析药物敏感性。采用 24 位位 MIRU-VNTR 和 spoligotyping 对结核分枝杆菌分离株进行分子基因分型。根据结核菌素皮肤试验（TST）的结果评估 LTBI。对与索引 TB 病例同住牢房的囚犯进行监狱内密切接触调查。
在有任何持续时间 RS 的 301/2020 名囚犯（15%）中，8%被诊断为活动性 TB。活动性 TB 的患病率为每 100,000 名囚犯中有 1,026 例。我们从 24 例（79%）TB 病例中分离出结核分枝杆菌，94.7%对一线药物敏感，只有 1 例对异烟肼单耐药。最常见的亚谱系是 Haarlem（68.4%），其次是 LAM（26.3%）和 T 超家族（5.3%）。24 位位 MIRU-VNTR 分型结果单独或与 spoligotyping 联合使用可识别出包含两个分离株的三个聚类。两个聚类对应于共享同一牢房的囚犯，但每个聚类都位于监狱的不同区域。最后一个聚类的囚犯在附近牢房的同一区域。95.6%的囚犯进行了 TST 读数，67.6%的结果为阳性。
监狱中的 LTBI 和 TB 患病率高于一般人群。分子基因分型表明，该监狱的 TB 主要由囚犯带入或内源性再激活的菌株引起。
