Antimicrobial coating is associated with significantly lower aerobic colony counts in high-touch areas in an orthopedic ward environment

The influence of physical environment on health care-associated infections: A literature review

BACKGROUND

Health care-associated infections (HAIs) are a common issue in health care settings, caused by environmental microorganisms, leading to health risks and financial strain. Despite efforts to reduce HAIs, the role of the physical environment in reducing HAIs is not fully understood. This literature review aimed to identify physical environment variables contributing to HAIs.

METHODS

A literature search was conducted in scientific databases between 2016 and 2022 using keywords associated with infections and physical environment variables. After screening retrieved articles for eligibility, the articles were analyzed for relevant environmental and infection variables.

RESULTS

Out of 145, 27 articles were identified. The findings were grouped into 8 categories, including layout design, surfaces, behavior, lighting, Internet of Things, materials, airflow, and air quality, with sub-themes in each group.

CONCLUSIONS

The physical environment in health care facilities plays a crucial role in reducing and preventing the spread of HAIs. Proper design and construction of health care buildings, including ventilation and air conditioning systems, help prevent infection spread between functional areas. Antimicrobial materials, cleaning and disinfection protocols, and personal hygiene practices, such as hand hygiene, are key factors in infection control. The positioning of hand hygiene stations is also essential to improve compliance among health care professionals.

Antimicrobial mechanism of cuprous oxide (Cu2O) coatings

Some very effective antimicrobial coatings exploit copper or cuprous oxide (Cu2O) as the active agent. The aim of this study is to determine which species is the active antimicrobial - dissolved ions, the Cu2O solid, or reactive oxygen species. Copper ions were leached from Cu2O into various solutions and the leachate tested for both dissolved copper and the efficacy in killing Pseudomonas aeruginosa. The concentration of copper species leached from Cu2O into aqueous solution varied greatly with the composition of the aqueous solution. For a range of solution buffers, killing of P. aeruginosa was highly correlated with the concentration of copper in the leachate. Further, 10 µL bacterial suspension droplets were placed on Cu2O coatings, with or without a polymer barrier layer, and tested for bacterial kill. Killing occurred without contact between bacterium and solid, demonstrating that contact with Cu2O is not necessary. We therefore conclude that soluble copper species are the antimicrobial agent, and that the most potent species is Cu+. The solid quickly raises and sustains the concentration of soluble copper species near the bacterium. Killing via soluble copper ions rather than contact should allow copper coatings to kill bacteria even when fouled, which is an important practical consideration.

Continuous surface and air decontamination technologies: Current concepts and controversies

Effective and safe continuous surface and air decontamination technologies could be a useful adjunct to routine cleaning and disinfection in health care settings. Continuously active quaternary ammonium disinfectants that provide residual antimicrobial activity on undisturbed surfaces for up to 24.ßhours have been shown to reduce the recovery of clinically important pathogens in some but not all real-world studies. Although quaternary ammonium-based supplemental coatings have been reported to provide prolonged residual efficacy in patient care settings, there is concern that some of these products may be removed by routine cleaning and disinfection. To address this concern, the Environmental Protection Agency has recently issued updated guidance requiring demonstration of efficacy after multiple abrasion and chemical exposures for registration of supplemental residual antimicrobial coatings. Far-ultraviolet-C and direct irradiation below exposure limits are promising technologies for continuous air and surface decontamination in occupied spaces, but additional studies are needed to evaluate their long-term safety and efficacy. Given the increasing use of electronic air cleaning technologies in community and health care settings, there is a need for studies to assess real-world efficacy and safety.