Use and efficacy of tuberculosis infection control practices at hospitals with previous outbreaks of multidrug-resistant tuberculosis

OBJECTIVE: To evaluate the implementation and efficacy of selected Centers for Disease Control and Prevention guidelines for preventing spread of Myco bacterium tuberculosis. DESIGN: Analysis of prospective observational data. SETTING: Two medical centers where outbreaks of multidrug-resistant tubercu losis (TB) had occurred. PARTICIPANTS: All hospital inpatients who had active TB or who were placed in TB isolation and healthcare workers who were assigned to selected wards on which TB patients were treated. METHODS: During 1995 to 1997, study personnel prospectively recorded inform ation on patients who had TB or were in TB isolation, performed observation s of TB isolation rooms, and recorded tuberculin skin-test results of healt hcare workers. Genetic typing of M tuberculosis isolates was performed by r estriction fragment-length polymorphism analysis. RESULTS: We found that only 8.6% of patients placed in TB isolation proved to have TB; yet, 19% of patients with pulmonary TB were not isolated on the first day of hospital admission. Specimens were ordered for acid-fast baci llus smear and results received promptly, and most TB isolation rooms were tinder negative pressure. Among persons entering TB isolation rooms, 44.2% to 97.1% used an appropriate (particulate, high-efficiency particulate air or N95) respirator, depending on the hospital and year; others entering the rooms used a surgical mask or nothing. We did not find evidence of transmi ssion of TB among healthcare workers (based on tuberculin skin-test results ) or patients (based on epidemiological investigation and genetic typing). CONCLUSIONS: We found problems in implementation of some TB infection contr ol measures, but no evidence of healthcare-associated transmission, possibl y in part because of limitations in the number of patients and workers stud ied. Similar evaluations should be performed at hospitals treating TB patie nts to find inadequacies and guide improvements in infection control (Injec t Control Hosp Epidemiol 2001;22:449-455).