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

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.