The fall after the rise: Tuberculosis in the United States, 1991 through 1994.

Abstract

Factors associated with decreases in tuberculosis cases observed in the United States in 1993 and 1994 were analyzed. Changes in case counts reported to the national surveillance system were evaluated by dividing the number of incident cases of TB reported in 1993 and 1994 by the number of cases reported in 1991 and 1992 and stratifying these ratios by demographic factors, AIDS incidence, and changes in program performance. Case counts decreased from 52,956 in 1991 and 1992 to 49,605 in 1993 and 1994 (case count ratio = 0.94, 95% confidence interval [CI] = 0.93, 0.95). The decrease, confined to US-born patients, was generally associated with AIDS incidence and improvements in completion of therapy, conversion of sputum, and increases in the number of contacts identified per case. Recent TB epidemiology patterns suggest that improvements in treatment and control activities have contributed to the reversal in the resurgence of this disease in US-born persons. Continued success in preventing the occurrence of active TB will require sustained efforts to ensure appropriate treatment of cases.