Efficacy and effectivity of uvc for hospitalar materials disinfection used in patients with COVID-19

Abstract

Background and Objectives: After the beginning of the COVID-19 pandemic, more effective and efficient means were needed to disinfect hospital materials. The objective of our study is to evaluate the in vitro efficacy and the economic effectiveness of type C ultraviolet (UVC) irradiation for disinfection of materials used in the care of COVID-19 patients. Methods. Four bipartite Cled plates were inoculated with suspensions of 10,000 CFU/mL of Escherichia coli and Staphylococcus aureus strains, exposed to two 18W lamps, placed inside a laminar flow and incubated for quantitative growth assessments. The germicidal equipment was built: the “UVC box” was developed with two 18W lamps for use in materials returned to pharmacy and a “UVC closet” with two 60W lamps for surgical gowns exposure. The economic effectiveness was evaluated by comparing inventory costs with quarantine of materials versus UVC usage costs. Results. Microbiological inactivation in the plates started after 4 minutes with an efficiency close to 100% at 8 minutes. The “UVC box” reduced the time to release the material from 9 days to immediately, generating savings of approximately R$ 68,400, and the “UVC closet” changed the use of surgical gowns to 0.7/patient, compared to the usual of 1.5, generating savings of nearly 3,000 reais/month. The cost of installation and maintenance was R$ 1,500. Conclusions. The efficacy and effectiveness of the UVC system was proven, as well as the economy promoted by its installation.