Assessing the efficacy of photocatalytic oxidation on bacterial contamination in a clinical setting – a randomised controlled trial

Abstract

Airborne contamination has been shown to be a significant source of wound contamination in orthopaedic surgery. This is the first reported study looking at the efficacy of ActivTek 300, a portable UV/TiO₂-based air purifier unit to reduce airborne contamination in a clinical setting. In this randomised study the investigator was blinded as to whether the unit had been on or off for the previous seven days.

Air contamination was measured weekly using a validated technique in ward treatment rooms using a Mini Air Sampler (MAS-100) and agar plates, over a period of 12 weeks. The agar plates were then incubated for 24 hours and the results were expressed as number of colony forming units per plate (cfu). The biomedical scientist who manually counted the number of cfus was blinded as to whether the unit was on or off. Measurements were duplicated to improve the accuracy of the study, and in addition to this an identical experiment was set up in a second treatment room on a separate randomisation schedule. Analysis of the data demonstrated median colony count was significantly lower with the unit on (Median = 43 interquartile range (IQR) 30 to 83) than when it was off (median = 95 IQR 44 to 143) (p < 0.01). This represents a 55% mean reduction in the colony count. This study suggests that the portable UV/TiO₂-based air purifier unit is efficacious in reducing airborne contamination in the clinical environment and may have a promising role in reducing overall infection rates in surgical patients.