Impact of mass-screening on tuberculosis incidence in a prospective cohort of Brazilian prisoners.

BACKGROUND: Globally, prison inmates are a high-risk population for tuberculosis (TB), but the specific drivers of disease and impact of mass screening interventions are poorly understood. METHODS: We performed a prospective cohort study to characterize the incidence and risk factors for tuberculosis infection and disease in 12 Brazilian prisons, and to investigate the effect of mass screening on subsequent disease risk. After recruiting a stratified random sample of inmates, we administered a questionnaire to ascertain symptoms and potential risk factors for tuberculosis; performed tuberculin skin testing (TST); collected sera for HIV testing; and obtained two sputum samples for smear microscopy and culture, from participants reporting a cough of any duration. We repeated the questionnaire and all tests for inmates who remained incarcerated after 1 year. TST conversion was defined as TST ≥10 mm and an induration increase of at least 6 mm in an individual with a baseline TST <10 mm. Cox proportional hazard models were performed to identify risk factors associated with active TB. To evaluate the impact of screening on subsequent risk of disease, we compared TB notifications over one year among individuals randomized to screening for active TB with those not randomized to screening. RESULTS: Among 3,771 inmates recruited, 3,380 (89.6 %) were enrolled in the study, and 1,422 remained incarcerated after one year. Among 1,350 inmates (94.9 %) with paired TSTs at baseline and one-year follow-up, 25.7 % (272/1060) converted to positive. Among those incarcerated for the year, 10 (0.7 %) had TB at baseline and 25 (1.8 %) were diagnosed with TB over the subsequent year. Cases identified through active screening were less likely to be smear-positive than passively detected cases (10.0 % vs 50.9 %; p < 0.01), suggesting early case detection. However, there was no reduction in subsequent disease among individuals actively screened versus those not screened (1.3 % vs 1.7 %; p = 0.88). Drug use during the year (AHR 3.22; 95 % CI 1.05-9.89) and knows somebody with TB were (AHR 2.86; 95 % CI 1.01-8.10) associated with active TB during one year of follow up CONCLUSIONS: Mass screening in twelve Brazilian prisons did not reduce risk of subsequent disease in twelve Brazilian prisons, likely due to an extremely high force of infection. New approaches are needed to control TB in this high-transmission setting.

The Impact of Ventilation and Early Diagnosis on Tuberculosis Transmission in Brazilian Prisons.

Prisoners have among the highest incidence of tuberculosis (TB) globally. However, the contribution of the prison environment on transmission is not well understood and structural characteristics have received little attention as effective epidemiological interventions in TB control. We evaluated architectural characteristics and estimated ventilation rates in 141 cells in three prisons in central west Brazil using steady-state exhaled carbon dioxide (CO2) levels. We used a modified Wells-Riley equation to estimate the probability of infection for inmates sharing a cell with an infectious case and projected the impact of interventions, including early diagnosis and improved ventilation. Overall, prison cells were densely populated (mean 2.1 m(2) per occupant) and poorly ventilated, with only three cells meeting World Health Organization (WHO) standards for per-person ventilation (60 L/s) applied in infection control settings. In the absence of interventions, projected mean risk of infection was 78.0% during a 6-month period. Decreasing time-to-diagnosis by 25% reduced transmission risk by 8.3%. Improving ventilation to WHO standards decreased transmission by 38.2%, whereas optimizing cross-ventilation reduced transmission by 64.4%. Prison environments promote high infection risk over short-time intervals. In this context, enhanced diagnostics have a limited impact on reducing transmission. Improving natural ventilation may be required to effectively control TB in prisons.

A Cross-Sectional Survey of HIV Testing and Prevalence in Twelve Brazilian Correctional Facilities.

BACKGROUND: Prior studies have reported higher HIV prevalence among prisoners than the general population in Brazil, but data have been derived from single prisons. The aim of this study was to evaluate HIV testing practices, prevalence and linkage to care among inmates in a network of 12 prisons. METHODS: We administered a questionnaire to a population-based sample of inmates from 12 prisons in Central-West Brazil and collected sera for HIV and syphilis testing from January to December 2013. We evaluated factors associated with HIV testing and infection using multivariable logistic regression models. Six months after HIV testing, we assessed whether each HIV-infected prisoner was engaged in clinical care and whether they had started antiretroviral therapy. RESULTS: We recruited 3,362 inmates, of whom 2,843 (85%) were men from 8 prisons, and 519 (15%) were women from 4 prisons. Forty-five percent of participants reported never having been tested for HIV previously. In multivariable analysis, the variables associated with previous HIV testing were lack of a stable partner (adjusted odds ratio [AOR]: 1.38; 95% CI: 1.18-1.60), completed more than four years of schooling (AOR 1.40; 95% CI: 1.20-1.64), history of previous incarceration (AOR: 1.68; 95% CI: 1.43-1.98), history of mental illness (AOR 1.52; 95% CI: 1.31-1.78) and previous surgery (AOR 1.31; 95% CI: 1.12-1.52). Fifty-four (1.6%) of all participants tested positive for HIV; this included 44 (1.54%) men and 10 (1.92%) women. Among male inmates, HIV infection was associated with homosexuality (AOR 6.20, 95% CI: 1.73-22.22), self-report of mental illness (AOR 2.18, 95% CI: 1.13-4.18), history of sexually transmitted infections (AOR 3.28, 95% CI: 1.64-6.56), and syphilis sero-positivity (AOR 2.54, 95% CI: 1.20-5.39). Among HIV-infected individuals, 34 (63%) were unaware of their HIV status; only 23 of these 34 (68%) newly diagnosed participants could be reached at six month follow-up, and 21 of 23 (91%) were engaged in HIV care. CONCLUSIONS: HIV testing rates among prison inmates are low, and the majority of HIV-infected inmates were unaware of their HIV diagnosis. Incarceration can be an opportunity for diagnosis and treatment of HIV among vulnerable populations who have poor access to health services, but further work is needed on transitional HIV care for released inmates.