Risk of Tuberculin Skin Test Conversion among Health Care Workers: Occupational versus Community Exposure and Infection

Open Access
Publisher Website
Google Scholar
Abstract
A prospective observational cohort study to assess rates of and risk factors for tuberculin skin test (TST) conversion among health care workers (HCWs) was conducted at an urban hospital located in a high tuberculosis—incidence area in 1994–1998. All hospital employees undergoing required testing every 6 months were included. A total of 69 (1.2%) of 5773 susceptible employees had a documented TST conversion (overall rate, 0.38 per 100 person-years worked). No significant difference existed in conversion rates among employees with frequent, limited, or no patient contact. HCWs with a TST conversion lived in zip codes with higher tuberculosis case rates (P ⩽ .05). In multivariate analysis, TST conversion was associated with history of bacille Calmette-Guérin vaccination (relative risk [RR], 11.63), annual salary <$20,000 (RR, 3.67), and increasing age. In the setting of an effective tuberculosis infection—control program, TST conversion rates were low, and risk of conversion among HCWs was associated most strongly with nonoccupational factors.