There is no doubt that there is an awareness of the importance of maintaining a clean and sterile environment in hospitals and clinics. However, no matter how diligent people are in their cleaning practices, there is always a risk of infection.
That is where antimicrobial surface coatings come in. These coatings are specially designed to help reduce the spread of harmful bacteria and viruses, making them a crucial tool in the fight against infections.
In this article, we will explore the benefits of antimicrobial surface coatings and why they are necessary to create a safe and hygienic enviroment.
Article originally published in German in “Tagesspiegel.Background”, a digital professional briefing of the leading Berlin daily newspaper “Tagesspiegel”, on 31 August 2021. The full original article can be found here: https://background.tagesspiegel.de/gesundheit/infektionsgeschuetzt-durch-beschichtungen
Wulf Schneider, infectologist at Regensburg University Hospital (Photo: private).
Using surface coatings to reduce infections
Hand hygiene and routine surface disinfection are often applied too sporadically to reliably put an end to germs. In contrast, antimicrobial coatings have the potential to revolutionize the fight against viruses and bacteria on surfaces in healthcare facilities, says infectologist Wulf Schneider, based in Regensburg, Germany.
Recently, the renowned journal “The Lancet Global Health” described what the current Covid-19 pandemic has already shown in a drastic way: The significance of hygiene in the context of infectious diseases, how rapidly success in health maintenance can be lost, and the importance of a resilient public health system.
Other authors also fear that the important fight against antibiotic resistance and multidrug-resistant bacteria is being pushed to the backburner by the Covid-19 pandemic, even though bacterial infections continue to kill countless people worldwide.
The human immune system usually provides effective protection against germs such as viruses and bacteria, except in people with already weakened immune responses. The risk of germ contamination is higher in places where large numbers of people congregate, with hospitals and other healthcare facilities being particularly sensitive areas.
Unfortunately, people are not always reliable
Demographic change, increasingly complex medical procedures, pandemics as well as the global surge in antibiotic-resistant bacteria all contribute to an increase in nosocomial infections, i.e. infections that occur in hospitals. One third of nosocomial infections are considered preventable – through better hygiene and infection control measures.
In many cases, germs are transmitted from person to person, which is why correct disinfection of hands should occur before and after contact with patients, before aseptic activities, after contact with potentially infectious materials and after contact with the patient environment. Unfortunately, people are not always that reliable, as recent studies show that the average hand hygiene compliance is at only about 40 percent.
Germs on surfaces sometimes remain infectious for weeks
Another problem is that non-disinfected hands also touch inanimate surfaces, which can be – in addition – also be contaminated by human aerosols containing viruses. Viruses and bacteria can survive and remain infectious for days or even weeks on inanimate surfaces, creating reservoirs of germs on such frequently touched surfaces, which can trigger nosocomial transmission to other people and surfaces with every further touch. Therefore, it is not surprising that numerous scientific studies now point to a connection between insufficient disinfection of surfaces close to patients and the occurrence of nosocomial infections.
Inanimate surfaces in healthcare facilities are usually disinfected according to a predefined plan. In contrast to hand hygiene, compliance with surface disinfection measures has only seen little scientific study and is sometimes measured at less than 50 percent. In addition, routine disinfection of surfaces is only effective at the time it is carried out. This is independent of how regularly and conscientiously it is carried out, which is unfortunately not always the case, even in healthcare facilities. Within minutes of disinfection, surfaces such as door handles, patient beds or medical equipment are already re-contaminated by being touched again.
Not all technologies deliver on what they promise
The use of antimicrobial surface coatings could potentially lead the way for preventing nosocomial transmission of germs in healthcare facilities. Routine surface disinfection works quickly, but only for a short time. Antimicrobial coatings are somewhat slower in their effect, but work independently and permanently, with a “compliance” of 100 percent. The simultaneous use of antimicrobial coatings and routine surface disinfection can provide a significantly improved concept of infection prevention.
In the past year, also driven by the Covid-19 pandemic, a large number of reputable and less reputable suppliers of antimicrobial coatings have appeared on the market. The coatings often use silver and copper ions, UV radiation or classical biocides, but not all approaches and technologies deliver on what they promise.
Antimicrobial coatings must meet some important criteria: First of all, no biocidal substances that potentially endanger people or the environment should be used. Since most inanimate surfaces are dry, the process must also work in this circumstance, i.e. not exclusively on wet or moistened surfaces. To ensure that this is the case, the currently used testing standards also need to be adapted or replaced. Biocidal processes must not generate resistances or co- or cross-resistances in antibiotic and antiseptic substances, as is for example the case with metal ions and quaternary ammonium compounds.
Several months of field tests required
The use of antimicrobial coatings should not be possible solely on the basis of laboratory tests and presenting a certificate. Rather, the product should prove its effectiveness under real everyday conditions in a field test over several months. This ensures that the coating fulfils its purpose, as has already been shown for innovative surface coating technology based on photo-dynamics.
In a comment in the publication “Nature Reviews Microbiology”, the authors point out that among other factors, the various efforts and experiences during the Covid-19 pandemic should be used to improve existing infection prevention measures. The authors call for a set of measures, including intensified antimicrobial stewardship, the use of artificial intelligence as well as new diagnostic and therapeutic procedures. Innovative hygiene procedures, in particular in the area of antimicrobial coating of surfaces, could form another important tool in this set – if they do not trigger further antibiotic resistances and manage to stand up to scientific scrutiny.
Professor Wulf Schneider is Head of the Department of Hospital Hygiene and Infectology at the University Hospital Regensburg in Germany.