[Results and significance of a baseline tuberculin skin test programme among health care workers in a hospital setting].

Background: Due to the resurgence of tuberculosis (Tb), health care workers (HCW) are considered at increased risk for Latent Tuberculosis Infection (LTI). According to the national guidelines health care facilities are required both to perform tuberculin skin tests (TsT) on all employees with potential occupational exposure to Tb and to analyze the results obtained. However, only a limited number of studies can be found in the literature reporting data of Tb prevalence in Italian hospitals.

Objectives: The aim of this study was to determine the prevalence of and the relative risks for positive TsT among employees of the Hospital of Cuneo.

Methods: After informed consent, a questionnaire and a TsT according to the Mantoux technique were administered to the 2368 employees of the hospital exposed to occupational risk for Tb. The variables considered for the univariate and multivariate analysis included several anthropometric, occupational and clinical factors

Results: 274 of the 2210 employees who completed the screening programme had positive TsT (12.4%). Only one subject had been treated for active Tb. Factors significantly associated with a positive TsT were duration of employment (odds ratio [OR]:4.90, CI: 2.25-10.66, for length of employment 10-17 years; and OR: 8.77, CI: 3.53-21.81, for length >17 years; p < 0.001); working in a Tb high-risk occupational setting (OR 4.26, CI: 1.90-9.57for level of "limited" risk and OR: 5.68, CI: 2.47-13.07 for level of "medium" risk; p < 0.001); belonging to nurse or assistant nurse job categories (OR: 2.80, CI: 1.09-7.19; p < 0.05); history of active or latent Tb infection (OR: 11.54, CI: 5.54-24.06; p < 0.001); birth in a foreign country (OR: 4.40, CI: 1.30-14.85; p = 0.01); and BCG immunization (OR: 2.51, CI: 1.68-3.75; p < 0.001). Seventeen subjects had a positive reaction after a two-step test (0.8%). Boosting occurred among elderly employees (mean age: 48, 3 +/- 8.0 yrs), with long duration of employment (22, 2 +/- 10.5 yrs), vaccinated with BCG (17/17).

Conclusions: Our data suggest that a baseline survey based on TsT is useful to assess the prevalence of and risk factors for TLI in a health care setting. The high rate of participation in the survey (93.3%) was probably due to the training and awareness efforts aimed specifically at exposed HCW.