Rapid recontamination with MRSA of the environment of an intensive care unit after decontamination with hydrogen peroxide vapour.

MRSA was isolated from 11.2% of environmental sites in 3 months preceding use of HPV and revealed that the types circulating within the environment were similar to those colonising patients. After patient discharge and terminal cleaning using conventional methods, MRSA was isolated from 5 sites (17.2%). After HPV decontamination but before the readmission of patients, MRSA was not isolated from the environment. Twenty-four hours after readmitting patients, including 2 colonized with MRSA, the organism was isolated from 5 sites. The strains were indistinguishable from a strain with which a patient was colonized but were not all confined to the immediate vicinity of the patient. In the following 8 weeks, the environment was sampled weekly and MRSA was isolated from 16.3% of sites. Journal of Hospital Infection 2007;66:360-8.