Self-Disinfecting Systems for Healthcare Facilities
In healthcare settings, disinfection is crucial to preventing the spread of microbes. Automated systems can aid in the fight against healthcare-acquired infections (HAIs). There are two different ways to automatically disinfect patient rooms: self-disinfecting surfaces and no-touch systems.
Surfaces constitute a significant factor in the spread of HAIs. Coatings and heavy metals can guard against microbial contamination leading to improved outcomes. Self-disinfecting surfaces are an emergent technology to control infection. Hospitals can coat bed rails, trays, call buttons, IV poles, and other items to make them self-disinfecting.
Copper ions are toxic to most microbes in high levels. It damages the nucleic acid, proteins, and lipids of bacteria and leads to cell death. In hospitals, copper is incorporated into self-disinfecting surfaces in rooms.
Contact with copper kills many pathogens such as MRSA, Escherichia coli, Enterococcus spp., and Mycobacterium tuberculosis. A study published in the Journal of Clinical Microbiology found that the introduction of copper led to “sustained reduction of microbial burden on common hospital surfaces.” However, more research is needed in this area. There are no specific standards as to the types of alloys used on surfaces.
Of all heavy metals, silver has the highest antimicrobial properties. Silver ions kill bacteria by binding with the disulfide and sulfhydryl groups in cell walls. A study published in the American Journal of Infection Control found that silver-based disinfectants reduced bacterial populations within minutes.
This has the potential to stop cross-contamination from environmental surfaces and lower the risk of HAIs. However, more research is needed to determine the clinical impact of using silver-imbued surfaces in healthcare settings.
Recent advancements use altered surface topography to prevent bio-films on indwelling medical devices. Sharklet Technologies developed a microscopic surface pattern that mimics shark skin. The antimicrobial properties are due to the unique shape and configuration of the surface micro-pattern. The engineered topography disrupts bacterial formation without the use of antibiotics.
Cellulose Acetate Coatings
Specific coatings of cellulose acetate can be antimicrobial under exposure to white light. Hospitals can coat surfaces with light-activated agents incorporated into polymers. This creates a self-disinfecting surface when exposed to ambient white light conditions. Applying light-activated antimicrobial coatings to surfaces can reduce environmental pathogens and reduce the risk of disease transmission. Cellulose Acetate Coatings give hospitals a less toxic approach than the use of chemical disinfectants. However, they need a constant source of photo-activation to work. More research is needed into the long-term, real-world effects.
Automated modalities are stand-alone machines that disinfect hospital rooms. No-touch procedures are adjunctive infection control measures and are not meant to replace the manual application of chemical disinfectants. Typically, automated methods are employed in final cleaning, and not for daily use. Two main types are commercially available – UV light and hydrogen peroxide mist.
The UV-C wavelength of light breaks down the molecular bonds of DNA, thus killing the microbes. UV-C technology kills a wide range of HAI pathogens. These types of automated systems are typically used for terminal room disinfection in hospital settings. To use ultraviolet disinfecting systems, move equipment and furniture away from walls to prevent shadowing. No humans should be present during UV disinfection.
Unfortunately, these systems take a significant amount of time and can affect bed turnover. Sufficient exposure time ranges from 50 to 100 minutes to eliminate C. difficile. UV-reflective wall coatings can shorten exposure times.
Hydrogen Peroxide Systems
There are several commercially available no-touch hydrogen peroxide systems, including dry mist and hydrogen peroxide vapor. An automated dispersal system uniformly applies hydrogen peroxide to a vacated hospital room which kills a variety of HAI pathogens. With these machines, furniture and equipment can remain in place during disinfection. However, air vents, doors, and windows must be sealed. These methods take time to allow the vapor to dissipate before humans can enter the room. Exposure to hydrogen peroxide mist could irritate airways and mucous membranes. Sensors monitor for leaks and alert staff when it is safe to enter.
Self-disinfecting surfaces and automated systems can aid in reducing HAIs. However, they are not replacements for proper cleaning and disinfection by housekeeping staff.