How quickly do hospital surfaces become contaminated after detergent cleaning?

Hospital cleanliness is important for controlling infection. This study aimed to determine the effect of detergent-based cleaning on microbial load at near-patient sites on one ward over a 48 h period. Lockers, left and right bedrails and overbed tables in 30 bed spaces were screened for aerobic colony counts (ACC) and staphylococci (methicillin-susceptible and methicillin-resistant Staphylococcus aureus: MSSA/MRSA) before detergent-based cleaning. Sites were rescreened at: 1, 2, 4, 8, 12, 24 and 48 h after cleaning. Microbial growth was quantified as number of ACC/cm2 and presence of MSSA/MRSA at each site. The study was repeated 3 times at monthly intervals. There was a significant reduction in average ACC (360 sites) from a pre-clean level of 6.72 ACC/cm2 to 3.46 ACC/cm2 at 4 hours after detergent-based cleaning (P < 0.0001). Average counts increased to 4.89 ACC/cm2 at 24 h and 5.27 ACC/cm2 at 48 h for all sites. Levels on bed rails and lockers, but not overbed tables, fell below a proposed standard (5 cfu/cm2) for 24 h after cleaning. MSSA/MRSA decreased 2–4 h after cleaning (P = 0.014) before increasing but failed to reach pre-clean levels. Detergent cleaning reduces ACC at near-patient sites on a hospital ward. S. aureus (including MRSA) was not completely eliminated but showed a similar pattern of decrease. Microbial burden at high-risk sites beside the patient could potentially be controlled by daily cleaning with single-use detergent wipes.