Background: In New York City, the incidence of tuberculosis has more than doubled during the past decade. We examined the incidence of tuberculosis and the acquired immunodeficiency syndrome (AIDS) and the rate of death from all causes in a very-high-risk group--indigent subjects who abuse drugs, alcohol, or both.
Methods: In 1984 we began to study prospectively a cohort of welfare applicants and recipients 18 to 64 years of age who abused drugs or alcohol. The incidence rates of tuberculosis, AIDS, and death for this group were ascertained through vital records and New York City's tuberculosis and AIDS registries.
Results: The cohort was followed for eight years. Of the 858 subjects, tuberculosis developed in 47 (5.5 percent), 84 (9.8 percent) were given a diagnosis of AIDS, and 183 (21.3 percent) died. The rates of incidence per 100,000 person-years were 744 for tuberculosis, 1323 for AIDS, and 2842 for death. In this group of welfare clients, the rate of newly diagnosed tuberculosis was 14.8 times that of the age-matched general population of New York City; the rate of AIDS was 10.0 times as high; and the death rate was 5.2 times as high. There was no significant difference in the rate of new cases of tuberculosis between subjects with positive skin tests and those with negative skin tests at examination in 1984.
Conclusions: Among indigent alcohol and drug abusers in New York City, the rates of tuberculosis, AIDS, and death are extremely high. In this population, a single positive or negative skin test does not predict the development of tuberculosis, probably because both anergy and new infections are common. If programs to control tuberculosis and AIDS are to be effective in groups of indigent substance abusers, health services must be integrated into the welfare delivery system.