Evaluation of a human immunodeficiency virus rule out tuberculosis critical pathway as an intervention to decrease nosocomial transmission of tuberculosis in the inpatient setting

Nosocomial transmission of Mycobacterium tuberculosis (TB) is a recognized risk in health care settings, and is a particular concern in settings where human immunodeficiency virus (HIV)-infected persons receive care. TB control guidelines have been effective in prevention of nosocomial TB outbreaks and protection of patients and health care workers. In 1993 a South Florida academic medical center noted an increase in TB cases, particularly in HIV-infected persons who had been inpatients. A multidisciplinary team developed an HIV Rule Out TB Critical Pathway as an intervention to deter nosocomial transmission of TB. The pathway was implemented in 1995 on the Special Immunology/Infectious Disease (SI/ID) inpatient unit. This paper describes an evaluation study conducted to determine the effectiveness of the pathway as an intervention to deter nosocomial TB in relation to two areas: (1) early identification of HIV-infected patients with potential TB, followed by immediate placement in respiratory isolation and (2) protection of SI/ID unit personnel from occupational TB exposure. A retrospective review was conducted in June 1999 on the medical records of all patients who had been placed on the HIV Rule Out TB Critical Pathway from 1995-1998. A review was also done of the medical center's confirmed TB cases, and employee health records for tuberculin skin testing (TST) of employees during this time period. The review demonstrated that all HIV-infected patients with confirmed TB had been identified, placed on the pathway and admitted to respiratory isolation at the onset of hospital admission, deterring the potential for a nosocomial TB outbreak. However, in 1998 two SI/ID staff converted from a nonreactive to a reactive TST. Although the pathway was only partially successful in TB protection for staff members, other factors may have caused the TST conversions. A study recommendation is that institutions develop an HIV Rule Out TB Critical Pathway, along with a Rule Out TB Pathway for patients who are not HIV-infected but present with symptoms that may be indicative of TB infection.