Increased time spent on terminal cleaning of patient rooms may not improve disinfection of high-touch surfaces

To the Editor—I read with great interest the study by Coppin et al, ¹ in which they attempted to determine whether increased cleaning time would improve disinfection of high-touch surfaces. ¹ Although I applaud the attempt to address the issue, I am concerned about the very limited description of their methods. I also feel that the methodological flaws limit any conclusions from their research.

First, the authors allowed for the use of 3 very different disinfectants. They did not describe how each was utilized. Also, they did not describe what the EVS staff did for the increased time. If the environmental services staff (EVS) was not cleaning first and then disinfecting, it is not surprising that there was limited effect. Doing something wrong for longer does not improve cleaning. Also, previous research that showed EVS was much less effective at disinfection when they were not monitored. ² They only cultured 5 surfaces, and they did not culture the mattress, which is the highest touch point for the patient.

The bed manufacturers, in their revised instructions for use, require 5–6 steps to be performed when terminally cleaning a bed. These steps, if done properly, require 35 minutes to 1 hour to complete.

The authors also did not report how they cultured for bacteria. This could have made a huge difference in the results of the study. There is no description of the actual colony-forming units of bacteria found in each group before and after cleaning. The authors should have reported the log reduction in bacteria for each group, and statistical significance should have been reported as well. The authors instead report predicted counts, which makes interpretation almost impossible.

I am concerned that this research will send the wrong message to hospitals: indicating that better cleaning will not work. It is extremely concerning that this research was funded by a manufacturer of an ultraviolet light disinfection machine. I strongly believe that cleaning better will not only decrease bacterial counts, but it will also decrease infections.