title: Impact of mass-screening on tuberculosis incidence in a prospective cohort of Brazilian prisoners.
abstract: 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.
authors.affiliation: Faculty of Health Sciences, Federal University of Grande Dourados, Dourados, Brazil.
authors.forename: Dayse Sanchez Guimarães
authors.initials: DS
authors.lastname: Paião
authors.affiliation: School of Medicine, Federal University of Mato Grosso do Sul, Campo Grande, Brazil.
authors.forename: Everton Ferreira
authors.initials: EF
authors.lastname: Lemos
authors.affiliation: Faculty of Health Sciences, Federal University of Grande Dourados, Dourados, Brazil.
authors.forename: Andrea da Silva Santos
authors.initials: AD
authors.lastname: Carbone
authors.affiliation: Faculty of Health Sciences, Federal University of Grande Dourados, Dourados, Brazil.
authors.forename: Renata Viebrantz Enne
authors.initials: RV
authors.lastname: Sgarbi
authors.affiliation: Faculty of Health Sciences, Federal University of Grande Dourados, Dourados, Brazil.
authors.forename: Alexandre Laranjeira
authors.initials: AL
authors.lastname: Junior
authors.affiliation: Faculty of Health Sciences, Federal University of Grande Dourados, Dourados, Brazil.
authors.forename: Fellipe Matos
authors.initials: FM
authors.lastname: da Silva
authors.affiliation: Faculty of Health Sciences, Federal University of Grande Dourados, Dourados, Brazil.
authors.forename: Letícia Marques
authors.initials: LM
authors.lastname: Brandão
authors.affiliation: Faculty of Health Sciences, Federal University of Grande Dourados, Dourados, Brazil.
authors.forename: Luciana Squarizi
authors.initials: LS
authors.lastname: Dos Santos
authors.affiliation: Faculty of Health Sciences, Federal University of Grande Dourados, Dourados, Brazil.
authors.forename: Vaneli Silva
authors.initials: VS
authors.lastname: Martins
authors.affiliation: Faculty of Ambiental and Biological Sciences, Federal University of Grande Dourados, Dourados, Brazil.
authors.forename: Simone
authors.initials: S
authors.lastname: Simionatto
authors.affiliation: Department of Biochemical Pharmacy, Federal University of Mato Grosso do Sul, Campo Grande, Brazil.|Oswaldo Cruz Foundation, Campo Grande, Brazil.
authors.forename: Ana Rita Coimbra
authors.initials: AR
authors.lastname: Motta-Castro
authors.affiliation: School of Medicine, Federal University of Mato Grosso do Sul, Campo Grande, Brazil.
authors.forename: Maurício Antônio
authors.initials: MA
authors.lastname: Pompílio
authors.affiliation: Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, CT, USA.
authors.forename: Juliana
authors.initials: J
authors.lastname: Urrego
authors.affiliation: Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, CT, USA.|Oswaldo Cruz Foundation, Salvador, Brazil.
authors.forename: Albert Icksang
authors.initials: AI
authors.lastname: Ko
authors.affiliation: Division of Infectious Diseases and Geographic Medicine, Stanford School of Medicine, Palo Alto, CA, USA.
authors.forename: Jason Randolph
authors.initials: JR
authors.lastname: Andrews
authors.affiliation: Faculty of Health Sciences, Federal University of Grande Dourados, Dourados, Brazil. juliocroda@gmail.com.|Oswaldo Cruz Foundation, Campo Grande, Brazil. juliocroda@gmail.com.
authors.forename: Julio
authors.identifier: http://orcid.org/0000-0002-6665-6825
authors.initials: J
authors.lastname: Croda
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001938:Brazil / Q000453:epidemiology; D015331:Cohort Studies; D003371:Cough; D005260:Female; D006801:Humans; D008297:Male; D008403:Mass Screening; D008875:Middle Aged; D011329:Prisoners / Q000706:statistics & numerical data; D011330:Prisons / Q000706:statistics & numerical data; D011446:Prospective Studies; D012307:Risk Factors; D019966:Substance-Related Disorders / Q000453:epidemiology; D011795:Surveys and Questionnaires; D014374:Tuberculin Test; D014376:Tuberculosis / Q000453:epidemiology*; D055815:Young Adult
keywords: Brazil; Case finding; Cohort; LTBI; Mass screening; Prisons; Tuberculosis