Ethiopian Medical Journal
Evaluation of the Efficacy of Ultraviolet-C Apparatus in Preventing the Transmission of Hospital Acquired Infections, Jimma University, Southwest Ethiopia
By Yibeltal Siraneh, Bikela Alemu, Lidet Tenaw and 4 others.
Abstract
Background
Ultraviolet light at a wavelength of 254 nm (UV-C) is recognized for its bactericidal, sporicidal, fungicidal, and virucidal properties. Defining the exact position, dose, and time of disinfection for a UV-C device in clinical settings is crucial to ensure its proper functioning and to achieve the anticipated disinfection efficacy. However, the efficacy of a newly designed UV-C device produced in Ethiopia has not yet been evaluated. Therefore, this study aimed to determine the antimicrobial efficacy of the newly designed device.
Methods
A laboratory-based experimental study was conducted starting from July 01 to 03, 2021, using different types of bacteria responsible for hospital-acquired infections, specifically those available from the American Type Culture Collection (ATCC). The bacteria tested included Pseudomonas aeruginosa ATCC 27853, Escherichia coli ATCC 25922, and Staphylococcus aureus ATCC 25923. Overnight cultures of microorganisms were harvested in sterile 0.85% saline, and the optical densities were adjusted to 0.5 McFarland standards (∼1.5 × 10^8 CFU/ml). These cultures were then exposed to light radiated from the new UV-C devices (same models with same UV intensity), with varying distances (in meters) and exposure times (in minutes), while control groups were maintained without exposure.