Healthcare Hygiene magazine July 2023 | Page 17

The takehome message here is that as we go from planktonic to biofilm to dry surface biofilm , it gets harder and harder to kill with disinfectants what traditionally would be able to eradicate planktonic ones with no problem .” with 5,000 parts per million ( ppm ) bleach with 5 minutes of contact ; that concentration of bleach can be tough on surfaces due to the amount of chlorine that is present . The point is that it is very challenging to achieve the kill levels we need to eradicate DSB , again , without any friction .”
Alfa next turned to the concept of mechanical friction while cleaning and disinfecting .
“ Scientists can be very creative people , so they took an abrasion tester , which was developed to assess abrasion impacts of various surfaces , and the units move back and forth in a linear fashion . Basically , these devices scrub 60 cm per second in linear motion , and they use this device to ask the question , ‘ How much of a role does friction play in removal of microorganisms ?’ It was kind of shocking . I expected that the DSB would be harder to eradicate in general , but this was even worse than I would have anticipated , with one back-and-forth wipe using a wipe wetted only with water , they were able to remove three and a half logs out of the total of six logs that were on the surface . So , planktonic organisms are actually very easy to remove with friction , without a disinfectant or a detergent , but just wetted with water . With a DSB , you don ’ t see any removal of material until after about 10 of those wipes , and if you perform 20 to 25 wipes , you ’ re maybe removing a log ’ s worth of bacteria .
The problem is , I don ’ t know anybody who is going to wipe a patient bed frame that many times . The important point here is that DSB is extremely difficult to remove , even when you ’ re using a lot of friction .”
Alfa related to the audience her experience where environmental services personnel were using a new disinfectant wipe as well as ATP to test and evaluate the cleaning of surfaces . “ What we found was when they switched over to this new product and were trained on it , we talked a lot about making sure that the surface was wetted appropriately , because you need three minutes of contact time to be effective in killing organisms . So , they focused more on getting the surface wet and they assumed that the disinfectant was going to kill the bugs without them putting a lot of effort into the process . It turns out they were using a lot less friction in their cleaning and wiping efforts , something we detected through our monitoring process . We had to retrain the environmental services personnel , reminding them that they can ’ t forget good old-fashioned elbow grease , because you really need friction in addition to the disinfection capability to kill and remove these microorganisms .”
Alfa emphasized that widespread assessment of the healthcare setting has shown that almost 95 percent of surfaces can have DSB on them , which can harbor multidrug-resistant organisms . “ This is a real challenge ,