Coating against hospital germs in the emergency room

Hospitals are gateways to viruses and bacteria. Emergency departments, in particular, are often affected by dangerous microbes. To reduce the germ load in hospitals, the NE-Offensive joint research project aims to develop antimicrobial coatings that offer permanent surface protection. They are designed to complement conventional hygiene practices and to keep dangerous germs at bay. The University Hospital Regensburg is now testing one of these types of coatings.

In this conversation with COMPAMED-tradefair.com, project manager Professor Michael Nerlich explains the unique characteristics of the emergency department and describes the testing procedure for the coating.

Professor Nerlich, where has the new surface coating been applied so far?

Michael Nerlich: The new surface coating was applied to various objects and surfaces in the central emergency room because it features especially high levels of harmful bacteria. There are two aspects that must be reconciled here because you cannot choose who comes into the emergency room, while things also have to move very fast, especially in life-threatening cases. In this setting, the staff members don’t have time to ask the patient if he or she might have an infectious disease. What’s more, an increased number of patients and a hectic emergency room environment may cause occasional lapses in disinfection practices, which in turn promote the transmission of germs. After all, if things have to move quickly, the staff is often too busy to let the hand disinfection take full effect and wait the recommended 30 seconds after application. Thirty seconds is an eternity when you have to treat life-threatening injuries. The cleanup of trauma bays may also have to be very fast. That’s why we conducted observational research in the emergency department and identified the areas and surfaces that are most frequently touched by the staff and patients. These are the areas where we test the antimicrobial surface coating. This is done by comparing two identical trauma bays. Both bays are coated; one coating contains the antimicrobial agent, the other does not.

How does the coating work?

The coating is made up of silver nanoparticles and DCOIT, which are biocides that are each very effective against gram-positive and gram-negative bacteria. This gives the coating an antimicrobial effect on many types of germs and kills bacteria. Dangerous germs include the Staphylococcus aureus bacterium which is often found in hospitals and nursing homes.

Does the function of the coating have to be restored on a regular basis?

We estimate that theoretically, surfaces that are not as frequently touched and cleaned on a daily basis can last up to ten years. This was also confirmed by various laboratory tests. Needless to say, some surfaces should be retreated sooner because the coating is attacked by acids or cleaning agents. The previous test setup offered full protection for more than 90 work days. In our study, fluorescence markers were integrated into the coating, which indicated whether the coating was still intact and effective during regular optical controls under UV light.

How do you check the effectiveness of the applied surface coating?

We studied a total of 2,880 discrete samples over a period of 90 days to determine whether there were any differences pertaining to germ count and the types of germs in the trauma bay with antimicrobial coating versus the trauma bay without an active agent in the coating. We take samples at regular intervals.

In our assumption, the overall germ load will be reduced thanks to the antimicrobial coating. What’s more, some extreme values, i.e., peak bacterial loads when a person with MRSA enters the environment, for example, could be contained. That being said, we won’t be able to start our evaluation of the complete data collection until March.