title: Prevalence of latent tuberculosis infection and risk of infection in patients with chronic kidney disease undergoing hemodialysis in a referral center in Brazil.
abstract: OBJECTIVE
  To determine the prevalence of latent tuberculosis infection (LTBI) and the risk of infection in patients with chronic kidney disease treated at a hemodialysis center.
  
  
  METHODS
  We included 307 patients with chronic kidney disease undergoing hemodialysis at the Mineiro Institute of Nephrology, located in the city of Belo Horizonte, Brazil. All of the patients were submitted to tuberculin skin tests (TSTs). We investigated the booster effect and TST conversion. If the initial TST (TST1) was negative, a second TST (TST2) was performed 1-3 weeks later in order to investigate the booster effect. If TST2 was also negative, a third TST (TST3) was performed one year after TST2 in order to determine whether there was TST conversion.
  
  
  RESULTS
  When we adopted a cut-off induration of 5 mm, the prevalence of LTBI was 22.2% on TST1, increasing by 11.2% on TST2. When we adopted a cut-off induration of 10 mm, the prevalence of LTBI was 28.5% on TST1, increasing by 9.4% on TST2. The prevalence of LTBI increased significantly from TST1 to TST2 (booster effect), as well as from TST2 to TST3 (p < 0.01 for both). In our sample, the mean annual risk of infection was 1.19%.
  
  
  CONCLUSIONS
  In the population studied, the prevalence of LTBI was high, and the mean annual risk of infection was similar to that reported for the general population of Brazil, which suggests recent infection.
authors.affiliation: Mineiro Institute of Nephrology, Belo Horizonte, Brazil.
authors.forename: Jane Corrêa
authors.initials: JC
authors.lastname: Fonseca
authors.forename: Waleska Teixeira
authors.initials: WT
authors.lastname: Caiaffa
authors.forename: Mery Natali Silva
authors.initials: MN
authors.lastname: Abreu
authors.forename: Katia de Paula
authors.initials: Kde P
authors.lastname: Farah
authors.forename: Wânia da Silva
authors.initials: Wda S
authors.lastname: Carvalho
authors.forename: Silvana
authors.initials: S
authors.lastname: Spindola de Miranda
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001938:Brazil / Q000453:epidemiology; D005260:Female; D006801:Humans; D055985:Latent Tuberculosis / Q000150:complications / Q000175:diagnosis / Q000453:epidemiology*; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D011446:Prospective Studies; D006435:Renal Dialysis; D051436:Renal Insufficiency, Chronic / Q000150:complications* / Q000628:therapy; D012307:Risk Factors; D018709:Statistics, Nonparametric; D014374:Tuberculin Test / Q000379:methods; D055815:Young Adult