[A study of tuberculosis infection in workers at a university general hospital: associated factors and evolution in 20 years].

OBJECTIVE To estimate the prevalence of tuberculous infection (TI) in the health-care workers of a hospital over the course of a 20-year period and analyze the associated risk factors. SUBJECTS AND METHODS A cross-sectional, descriptive study of the workers of a general hospital from 1988 until 2007, using a tuberculin test (TT) and questionnaire. RESULTS 2,179 workers were studied (mean age 32.4 years (SD 8.4). 24.5% worked in areas at risk for tuberculosis (TB). 8.1% (174) were vaccinated with BCG. The prevalence of positive baseline TT was 25.7% (95% confidence interval: 23.8-27.4%). There was a greater percentage of positive TT in the 1988-1992 period (44.2%) and a smaller percentage (15.8%) in the 2003-2007 period (P<.0001). The prevalence of TI was 1.53 times greater in males and 1.89 in those vaccinated with BCG. When compared with resident physicians, the prevalence of TI was greater in the rest of the professional categories, while increasing 1.03 times per year that age increases and 1.05 times per year of professional activity. CONCLUSIONS The data provide relevant information about the evolution of TI in hospital professionals over the course of a 20-year period. The prevalence decreased during the study period, probably due to a decrease in the incidence of TB in the reference community and to improved prevention measures and nosocomial control.