Factors associated with tuberculin reactivity in two general hospitals in Mexico

OBJECTIVE: To identify risk factors associated with tuberculin reactivity i n healthcare workers (HCWs). DESIGN: Cross-sectional survey of tuberculin reactivity (2 TU of purified p rotein derivative (PPD) RT23, using the Mantoux two-step test). SETTING: Two general hospitals located in a region with a high prevalence o f tuberculosis and high bacille Calmette-Guerin (BCG) coverage. PARTICIPANTS: Volunteer sample of HCWs. RESULTS: 605 HCWs were recruited: 71.2% female; mean age, 36.4 (standard de viation [SD], 8.2) years; 48.9% nurses, 10.4% physicians, 26.8% administrat ive personnel; mean time of employment, 10.9 (SD, 6.7) years. PPD reactivit y (greater than or equal to 10 mm) was found in 390 (64.5%). Multivariate a nalysis revealed an association of tuberculin reactivity with occupational exposure in the hospital: participation in autopsies (odds ratio [OR], 9.3; 95% confidence interval [CI95], 2.1-40.5; P = .003.), more than 1 year of employment (OR, 2.4; CI95, 1.1-5.0; P = .02), work in the emergency or radi ology departments (OR, 2.0; CI95, 1.03-3.81; P = .04), being physicians or nurses (OR, 1.5; CI95, 1.04-2.11; P = .03), age (OR, 1.04; CI95, 1.02-1.07 per year of age; P < .001), and BCG scar (OR, 2.1; CI95, 1.2-3.4; P=.005). CONCLUSIONS: Although the studied population has a high baseline prevalence of tuberculosis infection and high coverage of BCG vaccination, nosocomial risk factors associated with PPD reactivity were identified as professiona l risks; strict early preventive measures must be implemented accordingly ( Infect Control Hosp Epidemiol 2001;22:88-93).