Yield of continued monthly sputum evaluation among tuberculosis patients after culture conversion.

SETTING: New York City. OBJECTIVE: To evaluate the yield of continued monthly sputum monitoring after culture conversion. DESIGN: A retrospective review of tuberculosis patients verified between 1 January 1995 and 31 December 1996 who had: 1) pulmonary tuberculosis with organisms susceptible to isoniazid and rifampin; 2) culture conversion; and 3) completed therapy. We assessed time to smear and culture conversion and number of persons who developed a positive culture after culture conversion (culture reversion). RESULTS: Of 1440 patients, 379 were cared for by tuberculosis control program providers and 1061 were cared for by other providers; 813 (56%) were initially smear-positive. After the fifth month, 44 (5.3%) were smear-positive; four of these were culture-positive. Eighteen (1.3%) had culture reversions; eight were smear-positive. Excluding one specimen per patient collected at treatment completion, 7967 sputum samples were collected after culture conversion. The minimum estimated cost per culture reversion detected was $26,557. CONCLUSION: Continued monthly monitoring of sputum after culture conversion identified a very small number of patients who had culture reversion. However, patients who cannot tolerate or adhere to a standard regimen may need continued monitoring to assess response to treatment. For all patients a specimen should be collected at the end of treatment to document cure.

Relapse in persons treated for drug-susceptible tuberculosis in a population with high coinfection with human immunodeficiency virus in New York City.

The optimal duration of tuberculosis treatment for persons infected with human immunodeficiency virus (HIV) has been debated. A cohort of 4571 culture-positive drug-susceptible patients who received > or =24 weeks of standard 4-drug tuberculosis treatment were assessed to determine the incidence of tuberculosis relapse. Tuberculosis "recurrence" was defined as having a positive culture < 30 days after the last treatment date and "relapse" as having a positive culture > or =30 days after the last treatment. Patients infected with HIV were more likely than those who were uninfected to have recurrence or relapse (2.0 vs. 0.4 per 100 person-years, P< .001). Patients infected with HIV who received < or =36 weeks of treatment were more likely than those who received > 36 weeks to have a recurrence (7.9% vs. 1.4%, P< .001). Clinicians should be aware of the possibility of recurrence of tuberculosis 6-9 months after the start of treatment. Sputum evaluation to ensure cure or assessment 3 months after completion of treatment should be performed among persons infected with HIV who receive the shorter regimen.

A continuing survey of drug-resistant tuberculosis, New York City, April 1994.

BACKGROUND: A 1991 survey showed high levels of drug resistance among tuberculosis patients in New York, NY. As a result, the tuberculosis control program was strengthened, including expanded use of directly observed therapy and improved infection control. METHODS: We collected isolates from every patient in New York City with a positive culture for Mycobacterium tuberculosis during April 1994; results were compared with those in the April 1991 survey. RESULTS: From 1991 to 1994, the number of patients decreased from 466 to 332 patients. The percentage with isolates resistant to 1 or more antituberculosis drugs decreased from 33% to 24% (P < .01); with isolates resistant to at least isoniazid decreased from 26% to 18% (P < .05); and with isolates resistant to both isoniazid and rifampin decreased from 19% to 13% (P < .05). The number of patients with isolates resistant to both isoniazid and rifampin decreased by more than 50%. Among never previously treated patients, the percentage with resistance to 1 or more drugs decreased from 22% in 1991 to 13% in 1994 (P < .05). The number of patients with consistently positive culture results for more than 4 months decreased from 130 to 44. A history of antituberculosis treatment was the strongest predictor of drug resistance (odds ratio = 3.1; P < .001). Human immunodeficiency virus infection was associated with drug resistance among patients who never had been treated for tuberculosis. CONCLUSIONS: Drug-resistant tuberculosis declined significantly in New York City from 1991 to 1994. Measures to control and prevent tuberculosis were associated with a 29% decrease in the proportion of drug resistance and a 52% decrease in the number of patients with multidrug-resistant tuberculosis.