Nosocomial transmission of multidrug-resistant Mycobacterium tuberculosis

Abstract

Concomitant with the resurgence of tuberculosis in the United States have been increasing reports of nosocomial transmission of TB. From January 1990 through September 1992, the Centers for Disease Control (CDC) investigated eight nosocomial outbreaks of multidrug-resistant tuberculosis (MDR-TB). Over 200 patients were infected; approximately 75% of these patients died. Risk factors for infection included human immunodeficiency virus infection or acquired immunodeficiency syndrome and recent hospitalization on the same ward as other MDR-TB patients. Restriction fragment length polymorphism (RFLP) analysis of M. tuberculosis isolates revealed unique strains were transmitted in each hospital. In three hospitals, health care workers (HCW) assigned to wards with MDR-TB patients were shown to be more likely to have tuberculin skin test (TST) conversions than HCW assigned to wards without MDR-TB patients. These outbreaks demonstrate the serious morbidity and mortality associated with nosocomial MDR-TB and emphasize the importance of adhering to current CDC guidelines for preventing the transmission of tuberculosis in healthcare settings, with special focus on HIV-related issues.