Department of Medicine, Stanford University School of Medicine, Stanford, California, United States of America.
Agência Estadual de Administração do Sistema Penitenciário, Campo Grande, Brazil.
PLoS Med. 2019 Jan 24;16(1):e1002737. doi: 10.1371/journal.pmed.1002737. eCollection 2019 Jan.
It has been hypothesized that prisons serve as amplifiers of general tuberculosis (TB) epidemics, but there is a paucity of data on this phenomenon and the potential population-level effects of prison-focused interventions. This study (1) quantifies the TB risk for prisoners as they traverse incarceration and release, (2) mathematically models the impact of prison-based interventions on TB burden in the general population, and (3) generalizes this model to a wide range of epidemiological contexts.
We obtained individual-level incarceration data for all inmates (n = 42,925) and all reported TB cases (n = 5,643) in the Brazilian state of Mato Grosso do Sul from 2007 through 2013. We matched individuals between prisoner and TB databases and estimated the incidence of TB from the time of incarceration and the time of prison release using Cox proportional hazards models. We identified 130 new TB cases diagnosed during incarceration and 170 among individuals released from prison. During imprisonment, TB rates increased from 111 cases per 100,000 person-years at entry to a maximum of 1,303 per 100,000 person-years at 5.2 years. At release, TB incidence was 229 per 100,000 person-years, which declined to 42 per 100,000 person-years (the average TB incidence in Brazil) after 7 years. We used these data to populate a compartmental model of TB transmission and incarceration to evaluate the effects of various prison-based interventions on the incidence of TB among prisoners and the general population. Annual mass TB screening within Brazilian prisons would reduce TB incidence in prisons by 47.4% (95% Bayesian credible interval [BCI], 44.4%-52.5%) and in the general population by 19.4% (95% BCI 17.9%-24.2%). A generalized model demonstrates that prison-based interventions would have maximum effectiveness in reducing community incidence in populations with a high concentration of TB in prisons and greater degrees of mixing between ex-prisoners and community members. Study limitations include our focus on a single Brazilian state and our retrospective use of administrative databases.
Our findings suggest that the prison environment, more so than the prison population itself, drives TB incidence, and targeted interventions within prisons could have a substantial effect on the broader TB epidemic.
有人假设监狱是结核病（TB）一般流行的放大器，但关于这种现象及其对监狱为重点的干预措施的潜在人群影响的数据却很少。本研究（1）量化了囚犯在入狱和出狱期间的 TB 风险，（2）用数学模型计算了基于监狱的干预措施对一般人群中结核病负担的影响，（3）将该模型推广到广泛的流行病学背景。
我们从 2007 年至 2013 年获得了巴西马托格罗索州所有囚犯（n=42925）和所有报告的结核病病例（n=5643）的个人监禁数据。我们将囚犯和结核病数据库中的个人进行匹配，并使用 Cox 比例风险模型估计入狱和出狱时的结核病发病率。我们发现 130 例新诊断的入狱期间结核病病例和 170 例出狱后结核病病例。在监禁期间，结核病发病率从进入监狱时的每 100000 人年 111 例增加到 5.2 年时的每 100000 人年 1303 例。出狱时，结核病发病率为每 100000 人年 229 例，7 年后降至每 100000 人年 42 例（巴西的平均结核病发病率）。我们使用这些数据填充结核病传播和监禁的房室模型，以评估各种基于监狱的干预措施对囚犯和一般人群中结核病发病率的影响。在巴西监狱中进行年度大规模结核病筛查，将使监狱内的结核病发病率降低 47.4%（95%贝叶斯可信区间[BCI]，44.4%-52.5%），并使一般人群中的结核病发病率降低 19.4%（95%BCI 17.9%-24.2%）。一个广义模型表明，在监狱人群中结核病浓度较高且出狱人员与社区成员之间混合程度较高的人群中，基于监狱的干预措施将具有最大的降低社区发病率的效果。研究的局限性包括我们关注的是巴西的一个州，以及我们对行政数据库的回顾性使用。
我们的研究结果表明，监狱环境，而不是监狱人口本身，推动了结核病的发病率，而监狱内的针对性干预措施可能对更广泛的结核病流行产生重大影响。
