Anergy compromises screening for tuberculosis in high-risk populations.

Anergy may occur in groups at high risk for tuberculosis, compromising tuberculin skin testing. Within New York City's correctional system, anergy prevalence was 25% among opiate users referred to detoxification programs and 3% in the general population. Correlates of anergy were recent weight loss and needle sharing. The high prevalence of anergy among opiate users compromises the utility of tuberculosis screening and suggests the need for routine chest x-rays to detect pulmonary tuberculosis in some high-risk-populations.