Transfer of bacteria associated with cryotherapy.

The aim of this study was to determine whether living bacteria can be transmitted by cryosurgery with carbon dioxide. Cultures were taken from the outer layer of the ice before starting treatment, and again at the end of the working day during ten consecutive working days. Each of ten dry ice blocks was sterile prior to use. Staphylococcus epidermidis was isolated from six of the latter following use. This finding indicates that the dry ice was contaminated during the procedure and that bacteria were transmitted from the patient's skin to the dry ice and to culture media. The medical implications of this finding require serious consideration regarding the risk of infection to both patient and clinical personnel from this procedure.