Nosocomial transmission of Mycobacterium bovis bacille Calmette-Guerin to children receiving cancer therapy and to their health care providers.

A previous report of nosocomial infection due to Mycobacterium bovis bacille Calmette-Guerin (BCG) implicated contamination of chemotherapy solutions reconstituted under the same biosafety hood as BCG vaccine used for bladder cancer therapy. We report 3 similar BCG infections in children and describe evidence of respiratory transmission to health care workers (HCWs) from 1 patient. These children were receiving chemotherapy for leukemia when they presented with active tuberculosis. Each isolate was identified biochemically and by both gas-liquid chromatography and major polymorphic tandem repeat-polymerase chain reaction. Pulsed-field gel electrophoresis showed that 2 isolates were identical strains and identical to the Tice and Connaught strains licensed in the United States for bladder chemotherapy. The third isolate differed by a single fragment after DraI restriction. One patient with heavily positive sputum exposed numerous HCWs. Of 41 HCWs, 2 (5%) converted their purified protein derivatives (PPD) skin test. These data underscore the risk of nosocomial BCG transmission by contamination of chemotherapy solutions and demonstrate the potential for transmission to HCWs from patients with active pulmonary disease.