title: Incidence of tuberculosis infection among healthcare workers: risk factors and 20-year evolution.
abstract: OBJECTIVE
  To determine the incidence of latent tuberculosis infection (LTBI), and risk factors for tuberculosis skin test (TST) conversion among Healthcare workers (HCWs) during a 20-year follow-up period.
  
  
  METHODS
  Prospective cohort analysis. Surveillance was conducted from January 1, 1988, to December 31, 2007.
  
  
  METHODS
  600-bed tertiary referral hospital in Barcelona, Spain.
  
  
  METHODS
  HCWs in risk for occupational tuberculosis (TB) exposure, with negative baseline TST, direct contact with patients and/or biological samples and at least one follow-up visit with TST.
  
  
  METHODS
  TST is performed in HCWs with no previous history of TB or no previous positive TST. When TST is negative this test is performed once a year in high-risk workers, or at least every 2 years according to the hospital's guidelines. In all cases an interview questionnaire to gather information on possible risk factors was performed.
  
  
  RESULTS
  The study included 614 HCWs, 27% worked in areas of risk for TB exposure. Annual incidence rate had decreased from 46.8 per 100 person-years in 1990 to 1.08 per 100 person-years in 2007. Cumulative incidence was higher in HCWs who work in high-risk areas (p = 0.004) and in time periods from 1990 to 1995, and from 1996 to 2001 (p < 0.0001). Cox regression model showed a hazard ratio of 1.55 (CI 95%; 1.05-2.27) in high-risk workers, adjusted by gender, age and professional status.
  
  
  CONCLUSIONS
  Incidence of LTBI among HCWs is high, although it decreased throughout the follow-up period. It is crucial to maintain surveillance programs in HCWs.
authors: Preventive Medicine Service, Hospital Germans Trias i Pujol, Badalona, Spain. icasas.germanstrias@gencat.cat
authors: Irma
authors: I
authors: Casas
authors: Maria
authors: M
authors: Esteve
authors: Rosa
authors: R
authors: Guerola
authors: Ignasi
authors: I
authors: García-Olivé
authors: Juan
authors: J
authors: Roldán-Merino
authors: Carlos
authors: C
authors: Martinez-Rivera
authors: Juan
authors: J
authors: Ruiz-Manzano
mesh_terms: D000328:Adult; D001500:BCG Vaccine; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D017758:Infectious Disease Transmission, Patient-to-Professional / Q000706:statistics & numerical data; D053208:Kaplan-Meier Estimate; D055985:Latent Tuberculosis / Q000453:epidemiology* / Q000635:transmission; D008297:Male; D008875:Middle Aged; D009784:Occupational Diseases / Q000453:epidemiology* / Q000209:etiology; D016273:Occupational Exposure / Q000009:adverse effects / Q000032:analysis; D010564:Personnel, Hospital / Q000706:statistics & numerical data*; D012307:Risk Factors; D013030:Spain / Q000453:epidemiology; D014374:Tuberculin Test; D055815:Young Adult
chemical_list: D001500:BCG Vaccine