Some hospitals have long banned the status symbol of physicians – the white coat. Research has shown that especially the sleeves were contaminated with various types of bacteria. So it doesn’t help much when physicians thoroughly disinfect their hands but their coats stay "dirty". But it’s not just lab coats that can spread germs in healthcare settings. This field uses a variety of different textiles. Wouldn’t it, therefore, make sense to apply antimicrobial finishes? A new study provides answers.
Dr. Gerhardts, the healthcare sector needs to pay close attention to avoid the spread of germs. Are textiles specifically produced and tested in this area?
Anja Gerhardts: Depending on the application, textiles in the healthcare sector need to be produced in a sterile or nearly sterile manner. That’s why the statutory provisions primarily pertain to conducting a sterilization process or for textiles to be prepared in a disinfectant washing process. Having said that, it cannot be avoided that textiles are being contaminated with germs when they are being used. There are also functionalized textiles with barrier properties for example, for particularly sensitive areas like the operating room. Another functionalization is to equip textiles with antimicrobial agents that are designed to prevent bacteria or other pathogens from colonizing textiles. By killing the germs at the specifically designed fibers, bacterial spread through textiles is also indirectly being minimized. These effects are tested in laboratory tests by default; for instance, testing for antibacterial effectiveness according to DIN EN ISO 20743. However, conditions are different in practical use versus in laboratory tests.
You recently completed a study that focused on the practicability of antimicrobial textiles. What and how did you test?
Gerhardts: We have evaluated several antimicrobial textiles that are available on the German market under real-life conditions. That means we have modified the standard laboratory test in various parameters. In practice, pathogens are generally transmitted enclosed in an organic substance such as blood, saliva or ichor. These substances stabilize the bacteria and make them more resistant to environmental damages. We also wanted to find out whether nosocomial germs are killed on textiles within a short amount of time, for instance within 10 minutes. We also examined entirely different test germs under organic load and short residence times to create more realistic conditions during the laboratory test. Moreover, we investigated the infectious properties of antimicrobial textiles compared to uncoated textiles in germ transfer models. To do this, we tested how many bacteria are transferred onto a human hand by contaminated textile or how many germs are spread by a cleaning cloth during a wipe test.
The findings from these test models obviously are of greater importance for the practical use than findings of standard tests. This is where the wheat is separated from the chaff. Only a few of our test samples still showed any significant effectiveness against the test germs under the intensified realistic conditions. Nevertheless, our findings have shown that the use of antimicrobial clothing or bed linens in healthcare settings can be used as an additional hygiene measure. However, it is currently not widely used in practice.
How can manufacturers of these types of textiles improve their textiles?
Gerhardts: The textiles we investigated were based on different materials, manufacturing and equipment technologies and active substances. This is why our current data doesn’t permit us yet to make clear recommendations. Materials with doped fibers as well as coated materials proved to be suitable. We achieved the most effectiveness in this study with silver or biguanide-based products. At any rate, it is essential for the practicability of antimicrobial textiles that the active agent is available on the fiber surface to quickly interact with bacteria, while being adequately linked to achieve great washing resistance and durability of equipment at the same time. This is an enormous challenge and requires great technical know-how. Manufacturers should also always develop and optimize their products with practical application in mind. Tests with the newly developed practical test models can be utilized for this.
The IGF Project 17832 N by the research association Forschungskuratorium Textil e.V., Reinhardtstraße 12-14,10177 Berlin, was funded by the AiF within the industrial cooperation research program (IGF) of the German Federal Ministry for Economics and Energy based on a decision by the German Bundestag. The final report on this research is available to the interested public in the Federal Republic of Germany and can be obtained from the research center (Hohenstein Textile Institute of Innovation).