Virucidal efficacy of household dishwashers

Not only since SARS-CoV-2, have transmission routes of viruses been of interest. Noroviruses e.g., can be transmitted via smear infection, are relatively stable in the environment and very resistant to chemical disinfection. Some studies determined the virucidal efficacy of laundering processes, but few studies focused on the virucidal efficacy of dishwashing processes. Here, especially consumer related conditions are of interest. Households for example are a hotspot of norovirus infection and thus a sufficient reduction of these and other viruses from dishes must be insured to avoid an infection via this route. The likelihood of such an event should not be underestimated, since it was shown that the washing machine can be a reservoir for the transmission of extended spectrum beta-lactamase producing bacteria in newborns. Although viruses do not replicate in these devices a transmission via contaminated cutlery e.g., cannot be excluded. Using a consumer related approach to determine the virucidal efficacy of dishwashers, we found a combination of a bleach containing dishwasher detergent, a cleaning temperature of 45 C for 45 min and a rinsing temperature of 50 C, to be sufficient to reduces viral titer of bovine corona virus, murine norovirus and modified vaccinia virus by 4.8, 4.2 and 3.8 logarithmic stages respectively.Copyright © 2021 by the authors. Licensee MDPI, Basel, Switzerland.

Comparative efficacy evaluation of disinfectants against severe acute respiratory syndrome coronavirus-2.

BACKGROUND: Disinfection is one of the most effective ways to block the rapid transmission of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). Due to the prolonged coronavirus disease 2019 (COVID-19) pandemic, disinfectants have become crucial to prevent person-to-person transmission and decontaminate hands, clothes, facilities and equipment. However, there is a lack of accurate information on the virucidal activity of commercial disinfectants. AIM: To evaluate the virucidal efficacy of 72 commercially available disinfectants constituting 16 types of ingredients against SARS-CoV-2. METHODS: SARS-CoV-2 was tested with various concentrations of disinfectants at indicated exposure time points as recommended by the manufacturers. The 50% tissue culture infectious dose assay was used to calculate virus titre, and trypan blue staining and CCK-8 were used to assess cell viability after 3-5 days of SARS-CoV-2 infection. FINDINGS: This study found that disinfectants based on 83% ethanol, 60% propanol/ethanol, 0.00108-0.0011% sodium dichloroisocyanurate and 0.497% potassium peroxymonosulfate inactivated SARS-CoV-2 effectively and safely. Although disinfectants based on 0.05-0.4% benzalkonium chloride (BAC), 0.02-0.07% quaternary ammonium compound (QAC; 1:1), 0.4% BAC/didecyldimethylammonium chloride (DDAC), 0.28% benzethonium chloride concentrate/2-propanol, 0.0205-0.14% DDAC/polyhexamethylene biguanide hydrochloride (PHMB) and 0.5% hydrogen peroxide inactivated SARS-CoV-2 effectively, they exhibited cytotoxicity. Conversely, disinfectants based on 0.04-4% QAC (2:3), 0.00625% BAC/DDAC/PHMB, and 0.0205-0.14% and 0.0173% peracetic acid showed approximately 50% virucidal efficacy with no cytotoxicity. Citric acid (0.4%) did not inactivate SARS-CoV-2. CONCLUSION: These results indicate that most commercially available disinfectants exert a disinfectant effect against SARS-CoV-2. However, re-evaluation of the effective concentration and exposure time of certain disinfectants is needed, especially citric acid and peracetic acid.

Use of the European standardization framework established by CEN/TC 216 for effective disinfection strategies in human medicine, veterinary medicine, food hygiene, industry, and domestic and institutional use - a review.

The SARS-CoV-2 pandemic illustrates the necessity of effective preventive measures for existing and newly emerging pathogens. When confronted with pathogens or spoilage agents, especially if they are not yet well studied, effective hygiene protocols are needed immediately. In the medical field, effective preventive measures are key to prevent vulnerable patients from infections. In production areas, effective hygiene measures are needed to protect goods from spoilage or microbial contamination. The European standardization framework established by the European Committee for Standardization (CEN) ensures that effective hygiene measures are available and can be immediately implemented when needed. Based on a broad portfolio of standards/laboratory tests, activity claims specifically addressing the special features of applications of antimicrobial formulations are substantiated. In this review, the concept of using standardized surrogate test organisms is explained, and the European standardized test approach to claim microbicidal and virucidal efficacy, the specificity of claims and their relevance for infection prevention measures is illustrated. Furthermore, relevance of the European Norm test methods is elucidated in the light of legal requirements. Finally, the review explains the systematics of the standardized methodological portfolio of CEN, Technical Committee 216, which is very useful when effective strategies for fighting or preventing microbial and viral induced infections, contaminations or spoilage are needed on an immediate basis.

Virucidal efficacy of an ozone-generating system for automated room disinfection.

Besides conventional prevention measures, no-touch technologies based on gaseous systems have been introduced in hospital hygiene for room disinfection. The whole-room disinfectant device Sterisafe Pro, which creates ozone as a biocidal agent, was tested for its virucidal efficacy based on Association Française de Normalisation Standard NF T 72-281:2014. All test virus titres were reduced after 150 and 300 min of decontamination, with mean reduction factors ranging from 2.63 (murine norovirus) to 3.94 (simian virus 40). These results will help to establish realistic conditions for virus inactivation, and assessment of the efficacy of ozone technology against non-enveloped and enveloped viruses.

Emerging SARS-CoV-2 Mutational Variants of Concern Should Not Vary in Susceptibility to Microbicidal Actives.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is evolving, with emergence of mutational variants due to the error-prone replication process of RNA viruses, in general. More recently, the Delta and Omicron variants (including sub-variants BA.1-5) predominate globally, and a Delta-Omicron recombinant termed Deltacron has emerged. The emergence of variants of concern (VOC) demonstrating immune evasion and potentially greater transmissibility and virulence naturally raises concern in both the infection control communities and the public at large, as to the continued suitability of interventions intended to mitigate the risk of viral dissemination and acquisition of the associated disease COVID-19. We evaluated the virucidal efficacy of targeted surface hygiene products (an ethanol/quaternary ammonium compound (QAC)-containing disinfectant spray, a QAC disinfectant wipe, a lactic acid disinfectant wipe, and a citric acid disinfectant wipe) through both theoretical arguments and empirical testing using international standard methodologies (ASTM E1053-20 hard surface test and EN14476:2013+A2:2019 suspension test) in the presence of soil loads simulating patients' bodily secretions/excretions containing shed virus. The results demonstrate, as expected, complete infectious viral inactivation (≥3.0 to ≥4.7 log10 reduction in infectious virus titer after as little as 15 s contact time at room temperature) by these surface hygiene agents of the original SARS-CoV-2 isolate and its Beta and Delta VOC. Through appropriate practices of targeted surface hygiene, it is expected that irrespective of the SARS-CoV-2 VOC encountered as the current pandemic unfolds (and, for that matter, any emerging and/or re-emerging enveloped virus), the chain of infection from virus-contaminated fomites to the hand and mucous membranes of a susceptible person may be disrupted.