Is differential cleaning needed for SARS-CoV-2 beyond standard procedures? A systematic review.

BACKGROUND: There is a substantial risk of indirect transmission of SARS-CoV-2 from contaminated surfaces and objects in healthcare settings.

AIM: To evaluate the effectiveness of enhanced cleaning protocols for high-touch surfaces during COVID-19, focusing on cleaning products, concentrations, contact time, and recommended frequency.

SETTING: We focused on research conducted in healthcare settings or where samples were obtained from healthcare environments.

METHOD: We assessed studies that compared different cleaning, disinfection, sterilisation, or decontamination procedures and cleaning frequency with standard or routine procedures. We prioritised randomised trials, non-randomised controlled trials, controlled before-and-after studies, and interrupted time series analyses carried out between 01 January 2020 and 31 August 2022.

RESULTS: Three studies met our criteria from 2139 references searched. These studies, which took place in Iran, China and the United States, found that routine terminal cleaning and enhanced terminal cleaning with different cleaning enhancements significantly reduced SARS-CoV-2 surface contamination. One of the studies tested residual SARS-CoV-2 levels after routine and terminal cleaning with varying strengths of disinfectant and evaluated the efficacy of two common types of disinfectants in inactivating SARS-CoV-2 on inanimate surfaces in different hospital wards.

CONCLUSION: Limited evidence supports cleaning strategies that can reduce the transmission of SARS-CoV-2 from surfaces in healthcare settings. Combining various cleaning methods and using multiple disinfectants can effectively reduce surface contamination.

CONTRIBUTION: Randomised controlled trials are crucial for evaluating cleaning effectiveness. They must outline cleaning protocols, detailing frequency, product concentration and volume, application methods, soil and surface types, and environmental conditions, to provide strong evidence.