title: Prevalence of latent tuberculosis infection among health care workers in a hospital for pulmonary diseases.
abstract: BACKGROUND
  Little is known about the prevalence of latent tuberculosis infections (LTBI) in health care workers (HCW) in low-incidence countries especially in hospitals for pulmonary diseases. With Interferon-gamma release assays (IGRA), a new method for diagnosis of LTBI is available which is more specific than the tuberculin skin test (TST).
  
  
  OBJECTIVE
  The study was designed to estimate prevalence of LTBI among 270 HCW in a Hospital of Pulmonary Diseases routinely screened for TB.
  
  
  METHODS
  LTBI was assessed by the QuantiFERON-Gold In Tube (QFT-IT). Information on gender, age, workplace, job title, BCG vaccination and history of both TB and TST were collected using a standardised questionnaire. Adjusted odds ratios for potential risk factors for LTBI were calculated.
  
  
  RESULTS
  The prevalence of LTBI was 7.2%. In HCW younger than 30 years LTBI prevalence was 3.5% and in those older than 50 years 22%. Physicians and nurses showed a higher prevalence rate than other professions (10.8% to 4.5%). The putative risk factors for LTBI were age (>50 year OR 9.3, 95%CI 2.5-33.7), working as physicians/nurses (OR 3. 95%CI 1.2-10.4) and no previous TST in medical history (OR 4.4, 95%CI 1.01-18.9) when compared to those with a negative TST.
  
  
  CONCLUSIONS
  Prevalence of LTBI assessed by QFT-IT is low, this indicates a low infection risk even in hospitals for pulmonary diseases. No statement can be made regarding the occupational risk as compared to the general population because there are no LTBI prevalence data from Germany available. The higher LTBI prevalence rate in older HCWs might be due to the cohort effect or the longer time at risk.
authors.affiliation: Institution for Statutory Accident Insurance and Prevention in the Health and Welfare Services, Department of Occupational Health Research, Pappelallee 35-37, 22089 Hamburg, Germany.
authors.forename: Anja
authors.initials: A
authors.lastname: Schablon
authors.affiliation: Hospital of Pulmonary Diseases Großhansdorf Hamburg, Germany.
authors.forename: Gudrun
authors.initials: G
authors.lastname: Beckmann
authors.affiliation: Institution for Statutory Accident Insurance and Prevention in the Health and Welfare Services, Department of Occupational Health Research, Pappelallee 35-37, 22089 Hamburg, Germany.
authors.forename: Melanie
authors.initials: M
authors.lastname: Harling
authors.affiliation: School of Pulbic Health, Institute of Medical Sociology, University of Düsseldorf, Germany.
authors.forename: Roland
authors.initials: R
authors.lastname: Diel
authors.affiliation: Institution for Statutory Accident Insurance and Prevention in the Health and Welfare Services, Department of Occupational Health Research, Pappelallee 35-37, 22089 Hamburg, Germany.
authors.forename: Albert
authors.initials: A
authors.lastname: Nienhaus