SARS-CoV-2 RNA viability on high-touch surfaces and evaluation of a continuous-flow ozonation treatment

Background: The COVID-19 emergency has highlighted the importance of prevention systems and environ-mental microbiological monitoring as fundamental elements in the response to epidemics and other such threats to individual and collective health. The use of automated "No-touch" room disinfection systems eliminates or reduces the dependence on operators, thus allowing an improvement in the effectiveness of terminal disinfection. Study design: In the present study, we focused on possible SARS-CoV-2 contamination of surfaces of com-mercial services, and the effectiveness of ozone treatment on the virus. Methods: Analyses were conducted on 4-7 October and 27-30 December 2021 in four supermarkets in an Apulian city; supermarkets A and B were equipped with an ozonisation system, while C and D were without any environmental remediation. Results: SARS-CoV-2 RNA was detected by real-time RT-PCR only in December, in 6% of the surfaces tested, and all examined samples were found to be negative after viral culture, since no cytopathic effect was observed. A statistically significant difference emerged from the comparison of October vs. December (p = 0.0289), but no statistically significant difference (p = 0.6777) emerged from the comparison between supermarkets with and without the ozonisation system. Conclusions: Although no important changes were observed by treating the environments with ozonisation systems, further studies are needed to validate the effectiveness of environmental treatments with airborne disinfectants.