Tuberculosis screening in alcoholics and drug addicts.

To ascertain the value of screening for tuberculosis in the New York City (NYC) alcoholic and drug abusing welfare population, 2,641 clients were interviewed, and 970 (36.7%) of them met preestablished criteria for alcohol or drug abuse. The prevalence of active tuberculosis was 0.91%, which is 28 times the age-matched NYC rate. Screening only those persons with a positive PPD and a cough substantially increased the yield of active tuberculosis to 7.2%, or 225 times the NYC rate. The prevalence of a positive tuberculin skin test was 32.4%, or 1.5 times greater than the age-matched NYC rate. Treatment or prophylaxis for tuberculosis was required in 128 or 13.2% of the screened population. Seventy thousand NYC welfare clients are routinely evaluated for medical illness each year. This study predicts that in 1 yr this subpopulation could yield 239 clients with active tuberculosis and 3,181 requiring INH prophylaxis. Screening for tuberculosis in the alcoholic and drug abusing welfare clients is therefore urgently recommended.