Health-care-facility workers may receive exposures to droplet nuclei from confirmed or potential tuberculosis transmitters in outpatient clinics, emergency rooms, and similar locations where patients first make contact with health- care facilities and their workers. In most cases, the status of these patients as potential tuberculosis transmitters at this initial point of contact is not known. Workers in correctional facilities, homeless shelters, and other facilities where tuberculosis outbreaks may occur also come into close contact with persons with infectious tuberculosis before their transmitter status is known. When persons suspected of having, or diagnosed with, infectious tuberculosis are isolated, a limited number of health-care-facility workers are required to enter AFB isolation rooms to administer patient care, perform tests and procedures, and engage in other tasks. Persons with infectious tuberculosis may be transported from one isolation room to another through nonisolated areas of the facility. In each of these situations, health-care-facility workers may be exposed to aerosolized droplet nuclei. Hutton and Polder noted (45):
Until recently TB was probably not often transmitted in hospitals; when it was transmitted, it may have gone unrecognized because transmission did not result in rapid development of large clusters of active (and infectious) TB cases among contacts (both patients and HCFWs] . The recent outbreaks suggest that there may have been more of a problem with occult transmission of tuberculosis infection than was appreciated, especially in hospitals in high-incidence areas where there was a lack of TB surveillance among employees.
