Prevention of nosocomial transmission of Mycobacterium tuberculosis

The recent resurgence of TB together with the ongoing HIV epidemic has resulted in a larger number of infectious TB patients being admitted to US health care facilities. These patients have become a source for both nosocomial (patient-to-patient) and occupational (patient-to-health care worker) M. tuberculosis transmission. Infectious MDR-TB patients serve as even greater potential infectious sources because they often remain AFB smear and culture positive for months to years. The keys to the prevention of nosocomial and occupational transmission of M. tuberculosis is conducting a risk assessment for each area of the facility and instituting appropriate control measures, having a high index of suspicion by clinicians for infectious TB in those who present with consistent signs and symptoms, rapid triage of such patients to isolation areas and their appropriate clinical work-up, and the institution of effective antituberculous therapy. Infection control personnel should ensure that infectious TB patients are isolated in appropriate isolation rooms (i.e., negative pressure, greater than or equal to 6 ACH, and direct external exhaust of the room air). Health care workers with infectious TB patient contact should be instructed in the epidemiology of M. tuberculosis transmission, the role of respirators in protecting the health care worker from airborne inoculation, and the importance of periodic health care worker TST. The nosocomial TB outbreaks in the 1980s and 1990s document that M. tuberculosis can be transmitted to both patients and health care workers in US health care facilities when appropriate infection control measures are not fully implemented. Follow-up studies at some of these institutions, however, document that when infection control measures similar to the 1990 or 1994 CDC TB Guidelines are fully implemented, M. tuberculosis transmission to both patients and health care workers can be reduced or eliminated. Protection of both patients and health care workers from M. tuberculosis infection is dependent on an understanding and full implementation of the 1994 CDC TB Guidelines.