Exposure of emergency department personnel to tuberculosis: PPD testing during an epidemic in the community

Study objective: The present epidemic of tuberculosis has increased the risk of transmission of tuberculosis to health care workers in general and emergency department staff in particular, who often treat patients with tuberculosis before their diagnosis. The purpose of this study was to determine the risk of tuberculosis exposure among the nursing and physician staff of an urban ED. Design: Observational study of self-reported purified protein derivative (PPD) skin test results and tuberculosis exposure. Setting: Urban, public ED. Participants: Attending physicians, resident physicians, and registered nurses. Interventions: None Results: Questionnaires were sent to all attending physicians, resident physicians, and registered nurses in the ED at Harbor-UCLA Medical Center requesting information on the subject's present and prior PPD status, known exposure to tuberculosis, and duration of time and average number of hours worked in the ED. Ninety-six of 129 questionnaires (74%) were returned. Five of the respondents had been immunized with Bacillus of Calmette and Guerin vaccine (BCG) and 10 of the respondents were PPD positive before beginning work in the ED. Of the other 81 respondents, 31% (25 of 81) had become PPD positive while working in the ED. The majority of these conversions (15 of 25) occurred in the first 6 months of 1993. A Kaplan-Meier survival analysis revealed nearly a 40% risk of PPD conversion after 60 months of full-time work in the ED. Conclusion: As measured by self-reported PPD status, a high rate of exposure to tuberculosis has been observed among the ED staff at Harbor-UCLA Medica Center. The highest rate of PPD conversion has been noted most recently, suggesting that there has been a significant increase in staff exposure to tuberculosis during 1992 and the beginning of 1993. Systematic monitoring of PPD conversion rates among ED staff is necessary to determine the adequacy of ED respiratory isolation procedures during the current tuberculosis epidemic.