Reduction of bacterial load with the addition of ultraviolet-C disinfection inside the hyperbaric chamber

Abstract

INTRODUCTION: Healthcare acquired infections (HAIs) are associated with increased mortality, morbidity and prolonged hospital stays. Microbiological contamination of the hospital environment directly contributes to HAIs. Optimising environmental cleaning reduces transmission of HAIs. The hyperbaric chamber poses a specific challenge for infection control as certain disinfectants and alcohol-based hand sanitisers are prohibited due to fire risk. Patients often possess multiple risk factors for HAIs. This study compared the bacteria remaining on a surface (bioburden) after a standard clean and after adjunctive disinfection with an ultraviolet-C (UV-C) robot. METHODS: Internal hyperbaric chamber surfaces were first manually cleaned with Clinell® universal wipes and the floor was mopped with Whiteley neutral detergent. Allocated surfaces were swabbed using sterile cotton swabs and processed using a standard microbial culture and a bacteria-specific rapid metabolic assay. Bacterial contamination was also measured by direct contact plating on flat surfaces. The plexiglass ports were covered to protect from potential UV-C mediated damage and used as a negative control. A UV-C disinfection robot was then used to disinfect the chamber for 30 min, whereafter surfaces were swabbed again. RESULTS: There was a significantly greater mean reduction in bioburden following adjunctive UV-C disinfection than with standard cleaning alone. The surfaces not routinely manually cleaned (e.g., bench, phone) showed greatest reduction in bacterial load following UV-C cleaning. CONCLUSIONS: There was a significant reduction in the bacterial load in the chamber following an adjunctive UV-C clean compared with that of a standard clean. Adjunctive cleaning of the hyperbaric chamber environment with a non-touch UV-C device shows promise as a method to reduce HAIs.