title: High prevalence and risk factors associated with latent tuberculous infection in two Colombian prisons.
abstract: METHODS
  Two prisons in Medellín and Itagüí, Colombia.
  
  
  OBJECTIVE
  To determine the prevalence of tuberculin skin test (TST) positivity in prisoners and the annual risk of tuberculous infection (ARTI), to identify risk factors associated with a positive result, and to describe progression to active disease.
  
  
  METHODS
  Cross-sectional study. Inmates were included if time of incarceration was ⩾1 year and excluded if subjects had had previous or active tuberculosis (TB), or conditions that could hamper TST administration or interpretation.
  
  
  RESULTS
  We screened 1014 inmates. The overall prevalence of TST positivity was 77.6%. The first TST administration resulted in 66% positivity, and the second TST an additional 11.6%. In Prison One, the ARTI was 5.09% in high TB incidence cell blocks and 2.72% in low TB incidence blocks. In Prison Two, the ARTI was 2.77%. Risk factors associated with TST positivity were history of previous incarceration and length of incarceration. Among all those included in the study, four individuals developed active pulmonary TB.
  
  
  CONCLUSIONS
  Prevalence of TST positivity in prisoners and the ARTI were higher than in the general population, but differed between prisons; it is important to apply a second TST to avoid an overestimation of converters during follow-up.
authors.affiliation: Facultad de Medicina, Universidad Pontificia Bolivariana, Medellín, Colombia.
authors.forename: Z V
authors.initials: ZV
authors.lastname: Rueda
authors.affiliation: Facultad Nacional de Salud Pública, Medellín, Colombia.
authors.forename: L
authors.initials: L
authors.lastname: Arroyave
authors.affiliation: Grupo de Demografía y Salud, Facultad Nacional de Salud Pública, Medellín, Colombia.
authors.forename: D
authors.initials: D
authors.lastname: Marin
authors.affiliation: Grupo MICROBA, Escuela de Microbiología, Universidad de Antioquia, Medellín, Colombia.
authors.forename: L
authors.initials: L
authors.lastname: López
authors.affiliation: Laboratory of Viral Immunology, Department of Internal Medicine, Medical Microbiology and Community Health Sciences, University of Manitoba, Winnipeg, Canada.
authors.forename: Y
authors.initials: Y
authors.lastname: Keynan
authors.affiliation: Secretaría Seccional de Salud y Protección Social de Antioquia, Gobernación de Antioquia, Medellín, Medellín, Colombia.
authors.forename: M R
authors.initials: MR
authors.lastname: Giraldo
authors.affiliation: Secretaría de Salud de Bello, Alcaldía de Bello, Bello, Colombia.
authors.forename: H
authors.initials: H
authors.lastname: Pulido
authors.affiliation: Grupo de Epidemiología, Facultad Nacional de Salud Pública, Universidad de Antioquia, Medellín, Colombia.
authors.forename: M P
authors.initials: MP
authors.lastname: Arbeláez
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D015331:Cohort Studies; D003105:Colombia / Q000453:epidemiology; D003430:Cross-Sectional Studies; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D055985:Latent Tuberculosis / Q000175:diagnosis* / Q000453:epidemiology*; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D011329:Prisoners; D011330:Prisons; D012307:Risk Factors; D014374:Tuberculin Test / Q000379:methods; D014397:Tuberculosis, Pulmonary / Q000175:diagnosis / Q000453:epidemiology; D055815:Young Adult