DNA fingerprints from Mycobacterium tuberculosis isolates of patients confined for therapy noncompliance show frequent clustering.

Abstract

STUDY OBJECTIVE: To test the hypothesis that individuals chronically noncompliant with antituberculous chemotherapy are vectors for ongoing transmission of the disease in the community. DESIGN: Cohort study. SETTING: A large public hospital with a tuberculosis detention unit for patients with repeated and prolonged nonadherence to therapy. PATIENTS: Mycobacterium tuberculosis isolates from patients confined on the detention unit were obtained from the hospital's mycobacteriology laboratory. INTERVENTIONS: None. MEASUREMENTS AND RESULTS: A standardized IS6110-based Southern blot hybridization protocol was used to genotype M tuberculosis isolates recovered from patients confined on the detention unit at the hospital. Each DNA fingerprint pattern was compared with the IS6110-fingerprint database at the Public Health Research Institute Tuberculosis Center, which has archived fingerprint patterns from over 2,500 M tuberculosis isolates collected from New York City patients in the past 5 years. Eighty percent of available isolates from detained patients belonged to an identifiable DNA fingerprint cluster, suggesting an epidemiologic link between the detainees and other New York City tuberculosis patients. CONCLUSIONS: Chronic noncompliance with therapy is associated with ongoing spread of tuberculosis in the community. Aggressive measures, including detention, for the small number of recalcitrant, noncompliant patients may interrupt a chain of transmission and contribute to a decline in the spread of tuberculosis in urban areas.