Background: One of the limitations of current cleaning and disinfection strategies is that cleaned surfaces rapidly become recontaminated. In laboratory testing, a novel quaternary ammonium disinfectant provided sustained antimicrobial activity against multiple pathogens on surfaces after 24 hours. We hypothesized that this continuously active disinfectant would be effective in reducing contamination of portable medical equipment in a real-world healthcare setting.
Methods: In a hospital and affiliated long-term care facility, 114 portable devices were randomized to receive no treatment (N = 38) or a single spray application of a quaternary ammonium-alcohol disinfectant (N = 38) or of the continuously active disinfectant (N = 38). The devices were cultured at baseline and on days 1, 4, and 7 after treatment for total aerobic colony counts, methicillin-resistant Staphylococcus aureus (MRSA), and enterococci.
Results: As shown in Fig. 1, both spray disinfectants significantly reduced total aerobic colony counts in comparison to the untreated controls. The continuously active disinfectant resulted in sustained significant reductions in aerobic colony counts in comparison to baseline levels (P < .05), whereas counts returned to baseline levels by day 4 in the quaternary ammonium-alcohol disinfectant group. Recovery of MRSA and enterococci was significantly reduced on days 1–7 in the continuously active disinfectant group versus untreated controls (3 of 93, 3% vs 20 of 97, 21% respectively; P = .002), but not in the quaternary ammonium-alcohol disinfectant (11 of 97, 11%; P = .12). Conclusions: A single spray application of a continuously active disinfectant resulted in sustained reductions in total aerobic colony counts over 7 days and reduced recovery of MRSA and enterococci. The continuously active disinfectant could potentially reduce the risk for transmission of pathogens by portable devices.