Objective: To determine the incidence of bacille Calmette-Guérin (BCG) bacilli persisting in the urinary tract of patients treated previously with intravesical BCG for carcinoma in situ or multiple Ta.T1 transitional cell carcinoma.
Patients and methods: One-hundred and twenty-five patients were treated at the Freeman Hospital, Newcastle upon Tyne, UK over an 8-year period, 90 of whom submitted early morning urine samples for culture for acid-fast bacilli at varying intervals following BCG treatment. The records of all patients were reviewed to determine the incidence of caseating granulomata containing acid-fast bacilli together with the incidence of toxicity and the outcome of treatment.
Results: Five patients were found to have persisting acid-fast mycobacteria in their urine or bladder up to 16.5 months after completing intravesical instillations of BCG. In one patient this probably accounted for bladder symptoms that required palliative cystectomy. In four patients the 'infection' was not severe. Two patients were treated with antituberculous chemotherapy without complication. Three years after intravesical BCG therapy 36 of 69 patients (52%) had remained tumour free.
Conclusion: BCG organisms can persist in the urinary tract for at least 16.5 months after the completion of intravesical BCG instillation therapy.