Incidência e fatores de risco para tuberculose latente e ativa na população privada de liberdade em Mato Grosso do Sul

Abstract

Brazil has the world’s fourth largest prison population with rates of tuberculosis consistently exceeding 2,000 cases per 100,000 inmates. The Central-Western state of Mato Grosso do Sul has the highest rate of incarceration in Brazil, with approximately 12,306 inmates in 37 penal institutions. A 2013 study conducted in this setting found a low prevalence (8%) of latent tuberculosis infection among inmates who had been imprisoned for less than 1 month. The high prevalence of active tuberculosis, points to how penal institutions may be providing the ideal environment for persistent tuberculosis transmission. Epidemiologic studies are severely lacking. Only two studies have evaluated the incidence of latent tuberculosis infection in prisons in the United State, and no studies in countries with high disease burden. The aim of this study was to estimate the cumulative incidence and risk factors for tuberculosis in the inmate population of the state of Mato Grosso do Sul. The cohort was held in 12 prisons, 8 male and 4 female, in the cities of Campo Grande, Corumbá, Dourados, Ponta Pora, and Três Lagoas. This study used a stratified sample based on a cross-sectional study conducted in 2013, being held questionnaire and administered the tuberculosis skin test and smear microscopy in the baseline. After a year in return and repeat questionnaire, tuberculosis skin test and smear microscopy was all participants who were negative tuberculosis skin test at baseline and still incarcerated. The variables were entered in REDCap and analyzed in SAS. The Population Attributable Fraction Percent was calculated using the Levin formula. Of the 1,666 individuals who remained jailed 1 year, 1,422 individuals remained in the same prison; among 1060 previous negative-tuberculosis skin test individuals, 272 convert the tuberculosis skin test (26%, 95% CI 23-29) in one year of follow-up. The conversion rates in male patients ranged from 14% (95% CI 7-25) to 42% (95% CI 33- 53) and female varied from 3% (95% CI 1-19) and 15% (IC 95% 7-28). The average incidence of active tuberculosis among prisoners of Mato Grosso do Sul was 2.53%. Among the five largest cities in Mato Grosso do Sul, Campo Grande and Dourados stand out showing higher Population Attributable Fraction Percent 25.86% and 35.54%, respectively. There was a high force of infection (26%) and incidence (2,500 per 100,000 population) in prisons. The high rate of incarceration combined with extraordinary infection rates, indicate that prisons are important drivers of TB infection at the general population level. Urgent interventions are needed to address the unimpeded spread of tuberculosis in prisons globally.