Prevalence of PPD Positivity Among New Employees at a Hospital in New York City

Abstract

To determine the prevalence of tuberculin reactivity among all new employees at a hospital in New York City. Prospective measurement of purified protein derivative (PPD) status in consecutive new employees at a hospital in New York City from 1991 to 1993. All employees are tested as part of a preemployment physical, assuring complete compliance. Aplisol (Parke-Davis, Morris Plains, NJ) was used in 1991 and 1992, and Tubersol (Connaught, Swiftwater, PA) in 1993. Tests were applied and interpreted by trained employee health personnel. Of 313 consecutive new employees, comprising all job categories, 40% were PPD positive at time of initial hire, including 20% of US-born and 70% of foreign-born employees. Of 114 persons who had received BCG vaccination, 67% were PPD positive. By multivariate regression analysis, age, BCG vaccination history, and foreign country of birth were independent predictors of a reactive PPD test. The high prevalence of tuberculin reactivity may reflect high rates of Mycobacterium tuberculosis infection and disease in the community, complicating interpretation of the efficacy of Centers for Disease Control and Prevention (CDC) guidelines to prevent the spread of tuberculosis in healthcare facilities.