Risk factors for latent tuberculosis infection among healthcare workers in a university-affliated hospital

Abstract

Healthcare workers represent an important risk group for exposure, infection, and potentially disease by Mycobacterium tuberculosis. The aim of this study was to assess the prevalence and risk factors for latent tuberculosis infection among healthcare workers in a teaching hospital. A cross-sectional study was conducted in 2009 at the Fatemieh Hospital, Semnan, Iran. Information about age, gender, occupation, history of BCG vaccination and duration of employment was obtained by a structured questionnaire. All subjects received a Mantoux tuberculin skin test. Induration of ≥ 10 mm was considered a positive test. A total of 180 healthcare workers (60.5% female, 39.5% male) were enrolled. Twenty-fve (13.9%) had a positive skin test. History of BCG vaccination was detected in 159 (88.3%) of participants. In logistic regression analysis, employment for >five years (OR=4.10; 95% CI, 1.07-15.68) and for >10 years (OR=4.59; 95% CI, 1.45-14.59) was signifcantly associated with increased risk of a positive test. Age, gender, history of BCG vaccination and type of occupation were not signifcantly associated with a positive TST response. A low prevalence of latent tuberculosis infection was found among healthcare workers in this hospital. Longer duration of employment was signifcantly associated with increased risk of positive tuberculin skin test.