Evaluation of two-step tuberculin testing in a Massachusetts correctional facility

Abstract

Objectives: To better identify inmates with tuberculosis infection at admission and to have more accurate estimates of conversion rates with annual retesting, I evaluated two-step tuberculin skin testing of newly admitted inmates at the Addiction Center of the Massachusetts Department of Corrections.

Method: In a population of inmates admitted to the Addiction Center between January and May 1994, a second tuberculin skin test was performed 1 week after the first for those who initially had a negative response.

Results: There were 628 admissions during the study period; 51 of these inmates (8%) had a history of positive skin test results. Of the 570 initial tuberculin skin tests that were read, 12 (2.1%) had positive results. Five of 510 second tuberculin skin tests (1%) had positive results.

Conclusion: I evaluated the feasibility and utility of two-step tuberculin skin testing among newly admitted inmates at a Massachusetts correctional facility. We identified 40% more inmates with positive tuberculin skin test results after conducting 510 additional skin tests. Unlike the Addiction Center inmates, newly admitted inmates at other reception facilities are subject to interfacility transfer, and the rate of reading initial tuberculin skin tests is significantly lower than the 99% obtained at the Addiction Center. I expect serial testing to increase the identification of tuberculosis infected inmates at all facilities; however, its implementation should be deferred until a higher reading rate is obtained for the initial skin test.