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 bacill e 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 describ e 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 biochemica lly and by both gas-liquid chromatography and major polymorphic tandem repe at-polymerase chain reaction. Pulsed-field gel electrophoresis showed that 2 isolates were identical strains and identical to the Tice and Connaught s trains licensed in the United States for bladder chemotherapy The third iso late differed by a single fragment after DraI restriction. One patient with heavily positive sputum exposed numerous HCWs. Of 41 HCWs, 2 (5%) converte d their purified protein derivatives (PPD) skin test. These data underscore the risk of nosocomial BCG transmission by contamination of chemotherapy s olutions and demonstrate the potential for transmission to HCWs from patien ts with active pulmonary disease.