Staphylococcus aureus contamination on the surface of working tables in ward staff centers and its preventive methods.

We investigated Staphylococcus aureus (S. aureus) contamination on the surface of working tables in ward staff centers and the effects of disinfection by wiping with 80% (v/v) ethyl alcohol on this contamination. When working tables were not regularly disinfected or washed, S. aureus [methicillin-sensitive S. aureus (MSSA) and/or methicillin-resistant S. aureus (MRSA)] was detected in 29 (51.8%) of 56 tables in 6 wards investigated. MRSA was detected in 17 (30.4%) of 56 tables and in all investigated wards. The S. aureus contamination density on the entire surface of the S. aureus-contaminated tables was 2081+/-8915 (mean+/-S.D.) colony-forming units (cfu) (n=29, range, 10-4.8x10(4) cfu), and the MRSA contamination density on the entire surface of the MRSA-contaminated tables was 158+/-200 cfu (n=17, range, 10-7.4x10(2) cfu). The second investigation was performed immediately after working tables not regularly disinfected or washed were disinfected by wiping once with 80% (v/v) ethyl alcohol, and MRSA was detected in 5 (8.9%) of 56 tables. The contamination density on the entire surface of the MRSA-contaminated tables was 36+/-30 cfu (n=5, range, 10-80 cfu). The third investigation was performed immediately after working tables not regularly disinfected or washed were disinfected by wiping with 80% (v/v) ethyl alcohol twice with a 1-min interval, and no S. aureus contamination was observed in any of 56 tables. These results suggest that disinfection by wiping once with 80% (v/v) ethyl alcohol could not completely eliminate MRSA in particulates. For the disinfection of the MRSA-contaminated surface of working tables and the removal of particulates, regular disinfection by wiping with 80% (v/v) ethyl alcohol is necessary.