Ozone Plus UV-C Air Disinfection Effective for Hospital Pathogen Control

Ultraviolet (UV)-C irradiation in combination with ozone diffusion is superior to traditional disinfectants for reducing the concentration of the most common pathogens in health care settings. These study results were published in the Journal of Hospital Infection.

Researchers conducted a study to evaluate the effectiveness of ozone in combination with UV-C air treatment for sanitizing surfaces in hospital settings. Ozone and UV-C air treatment was delivered via the O3zy Light device, a contactless system consisting of a wheel-mounted portable ozone generator plus UV-C sanitizer. The effectiveness of the O3zy device was assessed at 3 hospitals in Italy during a 3-week period. The device was used in settings classified as low- and medium- to high-risk areas for hospital-acquired infection. Samples were collected from each setting once weekly for 3 consecutive weeks following use of the device and tested for Gram-positive (Staphylococcus aureus, non-β–haemolytic staphylococci, Clostridioides) and Gram-negative (Enterobacterales, Escherichia coli, Klebsiella, and Pseudomonas aeruginosa) bacteria, as well as mold and yeasts (Candida and Aspergillus species).

Samples were collected from a total of 240 low-risk and 144 medium- to high-risk areas. Low-risk areas included rehabilitation gyms and changing rooms, and high-risk areas included neurorehabilitation rooms.

In low-risk areas, UV-C irradiation of the air was performed continuously and ozone was used when areas were not occupied by patients. Overall, the combined use of UV-C and ozone treatment reduced the presence of Gram-negative bacteria by more than 99%. However, reductions in C difficile spores and Aspergillus species varied throughout the study. For C difficile, spores were reduced by 41% at week 0 and 79% at week 2; reductions in Aspergillus species during this period ranged between 44% and 97%. Of note, the effectiveness of UV-C plus ozone disinfection was associated with the number of treatments carried out over the 3-week period.

In medium- to high-risk areas, UV-C plus ozone treatment was effective against Gram-positive bacteria (S aureus and non-β-haemolytic staphylococci), Gram-negative bacteria, and Candida species. As with in low-risk areas, reduced susceptibility to the combined use of UV-C and ozone was observed for Clostridioides and Aspergillus species sampled from medium- to high-risk areas.

Limitations of this study include its short duration, potentially resulting in preliminary outcomes that are difficult to generalize to all hospital settings. In addition, further research is needed to compare the cost-effectiveness of no-touch sanitation devices with that of conventional cleaning procedures.

According to the researchers, “[T]he proposed no-touch device may be evaluated in future research to assess the needed requirements for its possible and full implementation in hospitals.”

This article originally appeared on Infectious Disease Advisor