COVID-19 outbreak: Should dental and medical practices consider uv-c technology to enhance disinfection on surfaces? – A systematic review

Abstract

Aims : During the COVID-19 pandemic the search for complementary methods to enhance manual disinfection in dental and medical practices raised relevance. We sought evidence for the addition of ultraviolet-C (UV-C) disinfection to manual cleaning protocols —and whether it improves the logarithmic (log) reduction of surface pathogen colonies. Methods : This review was registered at the International Prospective Register of Systematic Reviews (PROSPERO) under the number CRD420200193961. Six electronic sources were consulted looking for clinical trials performed in healthcare environments in which pathogens were quantified by colony-forming unit (CFU)-enumeration before and after interventions, all databases were last consulted on May 2021. We assessed the risk of bias using an adapted Revised Cochrane Risk of Bias Tool (RoB 2). The certainty of the evidence was qualified according to the Classification of Recommendations, Evaluation, Development, and Evaluation (GRADE) approach. Results : We identified 1012 records and 12 studies fulfilled the inclusion criteria. All included studies reported enhanced disinfection in the UV-C arm; most of them reported 1-log to 2-log reduction in approximately 10 to 25 minutes. Only three studies reached a 5-log and 6-log reduction. When manual cleaning was performed alone, only two studies reported a 1-log reduction using a chlorine-based disinfectant. We detected a high risk of bias in 1 study. Certainty of evidence was classified as moderate and low. Conclusions : The evidence points out the effectiveness of UV-C technology in reducing manual cleaning failures, enhancing the logarithmic reduction of surface pathogen colonies. However, the safety and success of these devices will depend on several physical and biological factors. A judicious project must precede their use in clinical and medical offices under the supervision of a physicist or other trained professional.

Shedding a light on ultraviolet-C technologies in the hospital environment

“…Other difficulties surrounding UV-C disinfection technology are the lack of a uniform standard applied for commercially available devices, the uncertainty about delivered doses, and the rather low quality of available research. This last drawback became clear while reviewing literature but is also reported by others [ [34] , [35] , [36] ]. The quality is often low due to low sample sizes, bias, and conflict of interest.…”

“…The quality is often low due to low sample sizes, bias, and conflict of interest. Further, it is also challenging to draw definite conclusions from literature data due to the heterogeneity across studies rendering the merge of data difficult [ [34] , [35] , [36] ].…”

“…After all, the large diversity in UV-C disinfection devices leads to different applications and parameter values. This makes it difficult to compare effectiveness across studies [ 34 ]. However, Alvarenga et al state, in their systematic review, that most studies report a 1-log to 2-log reduction for UV-C disinfection combined with manual precleaning for surfaces.…”

“…Further, Alvarenga et al mention that in laboratory experiments disinfection between 2- and 6-log was obtained. However, in real life, the achieved reductions might be lower due to suboptimal conditions including the presence of shadows and larger distances between the surface and the lamp [ 34 ]. It is therefore recommended to verify if the UV-C device performs as well for the intended application as under test conditions as RH and temperature can vary [ 46 ].…”

White light thermoplasmonic activated gold nanorod arrays enable the photo-thermal disinfection of medical tools from bacterial contamination

“…The germicidal UV lamps show emissions between 200 and 280 nm (UV-C). Although effective for disinfection, as UV-C light sources emit at 254 nm, they can induce several injuries, including sunburn, skin cancer, photokeratitis, retinal damages, 52,53 and corneal damages, 54 as this wavelength can damage DNA. UV-C radiation is also used in domestic air purifiers for air disinfection.…”