Burden of Occupationally Acquired Pulmonary Tuberculosis among Healthcare Workers in the USA: A Risk Analysis.

Abstract

Pulmonary tuberculosis (TB) infection remains an occupational health burden among healthcare workers (HCWs), but current surveillance data do not allow for attribution of pulmonary TB disease to occupational or community exposures. The objectives of this study were to estimate the annual number of occupationally acquired pulmonary TB infections among HCW in acute care settings (ambulatory care, emergency departments (EDs), and hospitals) in the USA, and to estimate the impact of increased compliance with respiratory protection. We used a risk analysis approach, in which occupational exposures were modeled using a compartmental model of bacilli transport and fate, and infection risk was estimated using two dose-response (DR) functions. With the conservative Wells-Riley DR function, we estimated 6420 occupationally acquired pulmonary TB infections annually in the USA, on average; with the more likely animal-based DR function, we estimated 3288 occupationally acquired pulmonary TB infections annually in the USA, on average. Increased (95%) compliance with respiratory protection would eliminate about one-third of pulmonary TB infections. Using results from the animal-based DR function, we estimated 82 cases of pulmonary TB disease will develop among US workers annually, on average, given 50% of infected HCW receive effective chemoprohylaxis and 5% of infections progress to disease. These results are consistent with national surveillance of pulmonary TB disease, and provide confidence that the analytical framework provides plausible results.