Evaluation of infection control parameters according to the 1994 Centers for Disease Control and Prevention tuberculosis guidelines: A 2-year experience

Background: Because of classification as a high-risk institution for potential Mycobacterium tuberculosis exposure and an employee purified protein derivative conversion rate of 2.7%, a large university-affiliated county hospital enhanced administrative and engineering controls, as recommended by its tuberculosis task force in early 1994. Methods: For 1994 and 1995 the medical records of all patients with culture-confirmed M. tuberculosis were reviewed according to the 1994 Centers for Disease Control and Prevention guidelines for case surveillance and risk assessment (infection control parameters). The χ2-test was used to compare 1994 and 1995 infection control parameters for statistical significance (p≤0.05). Results: In 1994 and 1995 there were 253 patients with tuberculosis, 85% of whom (214/253) had pulmonary-site tuberculosis. The “representative” patient with pulmonary tuberculosis was profiled, along with institution-specific surveillance data on diagnostics, medication regimens, and airborne isolation practices. Between 1994 and 1995 there was a trend toward increased numbers of homeless patients with tuberculosis, from 8.2% to 17% (p=0.07). Decreases in the numbers of HIV seropositive patients with tuberculosis from 35% in 1994 to 24% in 1995 (p=0.2) and of jailed patients with tuberculosis from 9.8% to 5% (p=0.5) were not significant. Drug-resistance patterns increased from 13% to 24%, with borderline significance (p=0.06). The employee purified protein derivative testing compliance rate increased from 49% in 1994 to 74% in 1995, with the purified protein derivative conversion rate also increasing from 2.7% to 3.5%. Conclusion: The infection control parameter data were beneficial in identification of institution-specific risk factors for our population with tuberculosis. Although labor-intensive, the annual tuberculosis reports supported requests for administrative and engineering controls; however, efficacy of the 1994 tuberculosis control plan was difficult to assess from purified protein derivative conversion rates alone, because the testing compliance rate also increased.