The U.S. Centers for Disease Control and Prevention (CDC) has revised its stance on healthcare facilities and the care of their floors.

Previously, its position was that extraordinary cleaning and decontamination of floors was unwarranted. This was based on studies that demonstrated the disinfection of floors offered no advantage over regular detergent/water cleaning, and had minimal or no impact on the occurrence of healthcare-associated infections (HAIs). In defending its reasoning, the CDC stated people in hospitals rarely touch floors and floors only need to be cleaned when visibly soiled, with the exception of operating rooms, which should be mopped at the end of each day.

In 2016, a group of researchers decided to test the CDC’s conclusions. They enrolled 10 hospital patients in a study. For each patient, a section of floor adjacent to their hospital bed was inoculated with sterile water containing bacteriophage, a virus that can infect bacteria and potentially destroy it. The floor areas were then allowed to dry.

None of the patients knew of the precise area of the inoculation and hospital staff was not made aware of the study.

All cleaning protocols remained the same during the research period. High-touch and commonly touched surfaces were cleaned with bleach and wipes each day. Following the CDC’s recommendations, floors were only cleaned when visibly soiled.

Just one day after commencement of the experiment, researchers detected bacteriophage on multiple surfaces near the patient beds. Within three days, the bacteriophage was detected on various surfaces within three feet of the beds. After three days, contamination was found on high-touch surfaces in adjacent hospital rooms, the nursing station and on portable equipment, such as wheelchairs, medication carts and vital signs equipment.

The researchers concluded the bacteriophage was likely acquired during direct contact with the contaminated floor adjacent to the hospital bed. During removal of footwear, patients could easily acquire the virus on their hands, with subsequent transfer to touched surfaces and other skin areas. The finding of contamination in adjacent rooms and the nursing station suggests that healthcare personnel contributed to the dissemination. This happened after acquiring the virus during contact with contaminated patients or surfaces.

According to ISSA education manager Mark Werner, people can have as many as 50 direct and indirect contacts with potentially contaminated floors every day. Contact may occur, for instance, when picking up items like pens, pencils, or paper that have accidentally fallen onto floors or tying shoelaces that have been in contact with floors.

It is also interesting to note that studies conducted in Wuhan, China have confirmed floors, at least in medical settings, can become contaminated with coronavirus. In one study, pre-moistened swabs were used to test floors in a hospital. “The rate of positivity was relatively high for floor swab samples, perhaps because of gravity and airflow causing most virus droplets to float to the ground,” wrote the researchers.

It’s also possible to inhale floor contaminants. A 2016 study published in the Journal of Applied Microbiology determined that from the floor, air currents, human movements over the floor, and other factors that aerosolize or provide an airborne opportunity for the organism may occur, causing human infections via inhalation or horizontal or cross-contamination from other persons, clothing, or equipment that the organism resettles upon.

So, what can be learned from these studies?

The CDC failed to recognize that people make scores of contacts with floors on a daily basis and pathogens on floors can become airborne. As well, while ‘extraordinary’ steps may not need to be taken to properly clean floors, the health protection agency’s claim that disinfectants are not required goes too far. An effective floor care program should comprise the use of effective disinfectants, detergents, cleaning agents and tools.

Speaking of tools, the CDC suggests that mops be used to clean floors. However, it’s well known that mops spread pathogens. No-mop floor cleaning alternatives like spray-and-vac systems were just being introduced in 2003, so it is possible the CDC was not aware of them at that time. Spray-and-vac has since been supplemented with dispense-and-vac and other no-mop cleaning systems, all of which have become standard floor care equipment in the cleaning industry.

The CDC also neglected to address cleaning frequency. In most healthcare facilities, keeping floors both visibly clean and healthy requires dividing floor care into three steps based on need: daily, periodic, and yearly maintenance.

Daily maintenance involves the removal of dry soils from surfaces, and vacuuming instead of sweeping is the healthiest way to perform this type of cleaning. Alternatively, floors can be cleaned using a no-mop floor care alternative. Periodic maintenance consists of scrubbing floors with an auto-vac floor cleaning system or automatic scrubber.

Once per year, floors should be refinished. This involves the removal of all finish from the floor and a new finish applied. However, if daily and periodic maintenance are performed frequently and correctly, this last step can be delayed for as much as two years.

The CDC has realized its past errors when it comes to floor care. Its recent guidelines place considerable emphasis on the need to keep floors clean and disinfected as much as possible in order to protect human health. They include: cleaning floors on a regular basis, when spills occur or visibly soiled; following manufacturer’s instructions for proper use of disinfecting products; preparing disinfecting solutions as needed and replacing with fresh solution frequently (for example, mopping solution should be changed after every three patient rooms and no less than at 60-minute intervals); decontaminating mop heads and cleaning cloths regularly to prevent contamination; and using an Environmental Protection Agency (EPA) registered hospital disinfectant designed for housekeeping purposes in patient care areas where there is uncertainty about the nature of the soil on the floor (for example, blood or body fluid contamination versus routine dust or dirt) or the presence of multi-drug resistant organisms.

The CDC now also has specific floor cleaning recommendations for when patients have certain, very contagious diseases. For instance, daily cleaning is required if a patient has Ebola, and the floor must be thoroughly cleaned and disinfected once that patient moves out of the room.

Robert Kravitz is a frequent writer for the professional cleaning industry.