THE FALL AFTER THE RISE - TUBERCULOSIS IN THE UNITED-STATES, 1991 THROUGH 1994

Objectives. Factors associated with decreases in tuberculosis cases ob served in the United States in 1993 and 1994 were analyzed. Methods. C hanges in case counts reported to the national surveillance system wer e 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 st ratifying these ratios by demographic factors, AIDS incidence, and cha nges in program performance. Results. Case counts decreased from 52 95 6 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 t o US-born patients, was generally associated with AIDS incidence and i mprovements in completion of therapy, conversion of sputum, and increa ses in the number of contacts identified per case. Conclusions. Recent TB epidemiology patterns suggest that improvements in treatment and c ontrol activities have contributed to the reversal in the resurgence o f this disease in US-born persons. Continued success in preventing the occurrence of active TB will require sustained efforts to ensure appr opriate treatment of cases.