Two-stage tuberculin testing with control antigens in patients residing in two chronic disease hospitals.

We studied the prevalence of tuberculin reactivity and anergy in 360 elderly patients residing in two municipal chronic disease hospitals. Eighty-five (26%) of the 323 patients tested had a positive reaction to a stage 1 tuberculin test and 12 (6%) of the 207 stage 1 tuberculin-negative patients exhibited a booster response to a stage 2 tuberculin test. Thirty percent of the same 207 patients had no response to an anergy panel of skin test antigens that included candida, mumps, and trichophyton. Nonresponders to tuberculin and the anergy panel had significantly higher one-year mortality rates compared to responders (44 v 20%, P = 0.001). Tuberculin-positivity among the 770 employees working in these facilities was 43%; 12 (4%) had a booster response. A survey of 29 randomly selected long-term care facilities in the Boston area indicated that all had a policy for pre-employment screening of employees, but less than 50% had a policy for patients and only one institution used two-stage testing. Routine tuberculin testing is recommended for long-term care facilities and the two-stage method is preferable in institutions with adequate resources.