As pathogens are transferred from shoes to floor, they are aerosolized by activities such as walking, equipment movement, HVAC systems, sweeping, vacuuming, or mopping. Floor bacteria in hospitals has been shown to account for up to 15% of airborne colony forming units (CFU’s) with walking contributing to their dispersal from floor to air.1 The aerosols generated from a contaminated floor can reach breathing height and are within respirable size range, meaning they are capable of transmitting infection through inhalation.2 Once aerosolized, these organisms can land on patient wounds or equipment, and suspend or redistribute through air currents and resettle on surfaces and floors.
“The floor is a primary source of contaminants since dust, airborne fungal spores, and bacteria tend to gravitate to the floor, and are easily stirred up by activity.” (The survival of bacteria in dust. II. The effect of atmospheric humidity on the survival of bacteria in dust. Lidwell and Lowbury 1950)
“Airborne concentrations of pathogens are typically higher near the floor.” (Hospital Airborne Infection-Kowalski 2008)
“Organisms on the floor can be re-suspended and become airborne.” (CDC Guidelines for Disinfection and Sterilization in Healthcare Facilities 2008)
“Once airborne an organism can travel and spread far and wide throughout the course of a day and present an inhalation hazard or they may settle on wounds, catheters, and other equipment and result in infections.” (Hospital Airborne Infection-Kowalski 2008)
1 Amirfeyz R.; Tasker A.; Ali S.; Bowker K. Blom A. :Theatre shoes – a link in the common pathway of postoperative wound infection?” The Royal College of Surgeons of England 2007; 89: 605-608
2 Paton S.; Thompson K.; Parks S.R.; Bennett A.M. “Reaerosolization of Spores from Flooring Surfaces To Assess the Risk of Dissemination and Transmission of Infections.” Applied and Environmental Microbiology Aug 2015 Vol. 81 Number 15