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1.
Photobiomodul Photomed Laser Surg ; 40(4): 273-279, 2022 Apr.
Article in English | MEDLINE | ID: covidwho-1830952

ABSTRACT

Objective: We report on the development and characterization of a UV-C light-emitting diode (LED) 280 nm cluster prototype device designed for the rapid disinfection of SARS-CoV-2 coronaviruses. The device was evaluated against the Betacoronavirus mouse hepatitis virus-3 strain, and its virucidal capacity was probed as a function of different applied UV-C doses versus different situations concerning irradiation distances. Background: UV-C LEDs are light emitters that offer advantages over low-pressure mercury lamps, such as quasimonochromaticity, lower electrical power consumption, instant on/off with the instant full-power operation, unlimited on/off cycles for disinfection schemes, and a much longer lifetime operation, in addition to portability aspects, as well as UV-C LEDs do not contain heavy metal in its composition such as mercury, found in ultraviolet germicidal irradiation (UVGI) lamps. Results: This novel device reached a 99.999% elimination rate at a distance of 9 cm at all the tested irradiation times (dose dependence), demonstrating that it took only 30 sec to achieve this inactivation rate. Its virucidal effectivity in rapid virus inactivation was demonstrated. Conclusions: We conclude that the HHUVCS cluster device (λp = 280 nm) provides a rapid virucidal effect against the SARS-CoV-2 coronavirus. The current research should encourage further advances in UV-C LED-based devices designed for the inactivation of SARS-CoV-2 virus on surfaces, in air, and in liquids.


Subject(s)
COVID-19 , Mercury , Animals , Disinfection , Mice , SARS-CoV-2 , Ultraviolet Rays
2.
Viruses ; 14(4)2022 Mar 25.
Article in English | MEDLINE | ID: covidwho-1820404

ABSTRACT

Recent research using UV radiation with wavelengths in the 200-235 nm range, often referred to as far-UVC, suggests that the minimal health hazard associated with these wavelengths will allow direct use of far-UVC radiation within occupied indoor spaces to provide continuous disinfection. Earlier experimental studies estimated the susceptibility of airborne human coronavirus OC43 exposed to 222-nm radiation based on fitting an exponential dose-response curve to the data. The current study extends the results to a wider range of doses of 222 nm far-UVC radiation and uses a computational model coupling radiation transport and computational fluid dynamics to improve dosimetry estimates. The new results suggest that the inactivation of human coronavirus OC43 within our exposure system is better described using a bi-exponential dose-response relation, and the estimated susceptibility constant at low doses-the relevant parameter for realistic low dose rate exposures-was 12.4 ± 0.4 cm2/mJ, which described the behavior of 99.7% ± 0.05% of the virus population. This new estimate is more than double the earlier susceptibility constant estimates that were based on a single-exponential dose response. These new results offer further evidence as to the efficacy of far-UVC to inactivate airborne pathogens.


Subject(s)
COVID-19 , Coronavirus OC43, Human , Disinfection/methods , Humans , SARS-CoV-2 , Ultraviolet Rays , Virus Inactivation
3.
Int J Environ Res Public Health ; 19(8)2022 04 17.
Article in English | MEDLINE | ID: covidwho-1809883

ABSTRACT

Healthcare-related infections are sustained by various bacteria and fungi. In recent years, various technologies have emerged for the sanitation of healthcare-related environments. This study evaluated the effectiveness of a no-touch disinfection system that aerosolizes 5% hydrogen peroxide and 10% ethyl alcohol. After selecting an environment, the Total Bacterial Count and the Total Fungal Count in the air and on a surface of the room were determined to evaluate the effectiveness of the aerosolization system. In addition, sterile stainless-steel plates inoculated with S. aureus, P. aeruginosa, and Aspergillus spp. isolated from hospitalized patients and reference strains were used to evaluate the effectiveness of the system. For each organism, three plates were used: A (cleaned), B (not cleaned), and C (control). The A plates were treated with non-ionic surfactant and the aerosolization system, the B plates were subjected to the aerosolization system, and the plates C were positioned outside the room that was sanitized. Following sanitization, air and surface sampling was conducted, after which, swabs were processed for bacterial and fungal enumeration. The results showed that the air sanitization system had good efficacy for both bacteria and fungi in the air and on stainless-steel plates, particularly for the A plates.


Subject(s)
Disinfectants , Disinfection , Aerosols , Bacteria , Delivery of Health Care , Disinfection/methods , Ethanol , Humans , Hydrogen Peroxide , Pseudomonas aeruginosa , Stainless Steel , Staphylococcus aureus
4.
Sci Rep ; 12(1): 5869, 2022 04 07.
Article in English | MEDLINE | ID: covidwho-1778639

ABSTRACT

The ongoing COVID-19 global pandemic has necessitated evaluating various disinfection technologies for reducing viral transmission in public settings. Ultraviolet (UV) radiation can inactivate pathogens and viruses but more insight is needed into the performance of different UV wavelengths and their applications. We observed greater than a 3-log reduction of SARS-CoV-2 infectivity with a dose of 12.5 mJ/cm2 of 254 nm UV light when the viruses were suspended in PBS, while a dose of 25 mJ/cm2 was necessary to achieve a similar reduction when they were in an EMEM culture medium containing 2%(v/v) FBS, highlighting the critical effect of media in which the virus is suspended, given that SARS-CoV-2 is always aerosolized when airborne or deposited on a surface. It was found that SARS-CoV-2 susceptibility (a measure of the effectiveness of the UV light) in a buffer such as PBS was 4.4-fold greater than that in a cell culture medium. Furthermore, we discovered the attenuation of UVC disinfection by amino acids, vitamins, and niacinamide, highlighting the importance of determining UVC dosages under a condition close to aerosols that wrap the viruses. We developed a disinfection model to determine the effect of the environment on UVC effectiveness with three different wavelengths, 222 nm, 254 nm, and 265 nm. An inverse correlation between the liquid absorbance and the viral susceptibility was observed. We found that 222 nm light was most effective at reducing viral infectivity in low absorbing liquids such as PBS, whereas 265 nm light was most effective in high absorbing liquids such as cell culture medium. Viral susceptibility was further decreased in N95 masks with 222 nm light being the most effective. The safety of 222 nm was also studied. We detected changes to the mechanical properties of the stratum corneum of human skins when the 222 nm accumulative exposure exceeded 50 J/cm2.The findings highlight the need to evaluate each UV for a given application, as well as limiting the dose to the lowest dose necessary to avoid unnecessary exposure to the public.


Subject(s)
COVID-19 , Viruses , COVID-19/prevention & control , Disinfection , Humans , SARS-CoV-2 , Ultraviolet Rays , Virus Inactivation/radiation effects
5.
Sci Rep ; 12(1): 4373, 2022 03 23.
Article in English | MEDLINE | ID: covidwho-1758367

ABSTRACT

Many infectious diseases, including COVID-19, are transmitted by airborne pathogens. There is a need for effective environmental control measures which, ideally, are not reliant on human behaviour. One potential solution is Krypton Chloride (KrCl) excimer lamps (often referred to as Far-UVC), which can efficiently inactivate pathogens, such as coronaviruses and influenza, in air. Research demonstrates that when KrCl lamps are filtered to remove longer-wavelength ultraviolet emissions they do not induce acute reactions in the skin or eyes, nor delayed effects such as skin cancer. While there is laboratory evidence for Far-UVC efficacy, there is limited evidence in full-sized rooms. For the first time, we show that Far-UVC deployed in a room-sized chamber effectively inactivates aerosolised Staphylococcus aureus. At a room ventilation rate of 3 air-changes-per-hour (ACH), with 5 filtered-sources the steady-state pathogen load was reduced by 98.4% providing an additional 184 equivalent air changes (eACH). This reduction was achieved using Far-UVC irradiances consistent with current American Conference of Governmental Industrial Hygienists threshold limit values for skin for a continuous 8-h exposure. Our data indicate that Far-UVC is likely to be more effective against common airborne viruses, including SARS-CoV-2, than bacteria and should thus be an effective and "hands-off" technology to reduce airborne disease transmission. The findings provide room-scale data to support the design and development of effective Far-UVC systems.


Subject(s)
COVID-19 , Staphylococcal Infections , Disinfection , Humans , SARS-CoV-2 , Ultraviolet Rays
6.
Int J Environ Res Public Health ; 19(6)2022 03 10.
Article in English | MEDLINE | ID: covidwho-1742427

ABSTRACT

BACKGROUND: The reprocessing of medical devices has become more complex due to increasing hygiene requirements. Previous studies showed satisfactory bactericidal disinfection effects of UV-C light in rigid and flexible endoscopes. Especially in the context of the current COVID-19 pandemic, virucidal properties are of high importance. In the present study, the virucidal efficacy of UV-C light surface disinfection was analyzed. METHODS: MS-2 bacteriophages were applied to the test samples and irradiated by UV-C light using the UV Smart D25 device; unirradiated test samples were used as controls. A dilution series of the samples was mixed with 1 × 108 Escherichia coli and assayed. RESULTS: 8.6 × 1012 pfu could be harvested from the unprocessed test samples. In the control group without UV-C exposure, a remaining contamination of 1.2 × 1012 pfu was detected, resulting in a procedural baseline reduction rate with a LOG10 reduction factor of 0.72. The LOG10 reduction factor was found to be 3.0 after 25 s of UV-C light exposure. After 50 and 75 s of UV-C radiation LOG10 reduction factors 4.2 and 5.9, respectively, were found, with all reductions being statistically significantly different to baseline. CONCLUSIONS: The tested UV system seems to provide a significant virucidal effect after a relatively short irradiation time.


Subject(s)
Bacteriophages , COVID-19 , COVID-19/prevention & control , Disinfection/methods , Humans , Pandemics , Ultraviolet Rays
7.
Appl Environ Microbiol ; 88(7): e0214821, 2022 04 12.
Article in English | MEDLINE | ID: covidwho-1741570

ABSTRACT

UV light is a tool associated with the denaturation of cellular components, DNA damage, and cell disruption. UV treatment is widely used in the decontamination process; however, predicting a sufficient UV dose by using traditional methods is doubtful. In this study, an in-house UVC apparatus was designed to investigate the process of the inactivation of five indicator bacteria when the initial cell concentrations and irradiation intensities varied. Both linear and nonlinear mathematical models were applied to predict the inactivation kinetics. In comparison with the Weibull and modified Chick-Watson models, the Chick-Watson model provided a good fit of the experimental data for five bacteria, Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus, Streptococcus faecalis, and Bacillus subtilis. The specific death rate (kd) significantly increased when the irradiation intensity (I) increased from 1.41 W/m2 to 3.02 W/m2 and 4.83 W/m2 (P < 0.05). Statistical analysis revealed no significant difference in the kd values among the groups of tested Gram-positive bacteria, Gram-negative bacteria, and B. subtilis spores, but the kd values differed among groups (P < 0.05). The death rate coefficient (k) varied from species to species. The k values of the tested Gram-positive bacteria were higher than those of the Gram-negative bacteria. The thick peptidoglycan layer in the Gram-positive membrane was responsible for UVC resistance. The high guanine-cytosine (GC) content in bacteria also contributed to UV resistance due to the less photoreactive sites on the nucleotides. This investigation provides a good understanding of bacterial inactivation induced by UVC treatment. IMPORTANCE Prevention and control measures for microbial pathogens have attracted worldwide attention due to the recent coronavirus disease 2019 pandemic. UV treatments are used as a commercial control to prevent microbial contamination in diverse applications. Microorganisms exhibit different UV sensitivities, which are often measured by the UV doses required for decreasing the number of microbial contaminants in the logarithmic order. The maximum efficacy of UV is usually observed at 254 nm (residing in the UVC range of the light spectrum). UV technology is a nonthermal physical decontamination measure that does not require any chemicals and consumes low levels of energy while leaving insignificant amounts of chemical residues or toxic compounds. Therefore, obtaining the microbial death kinetics and their intrinsic parameters provided in this study together with the UV photoreaction rate enables advancement in the design of UV treatment systems.


Subject(s)
COVID-19 , Decontamination , Bacteria/radiation effects , Disinfection/methods , Gram-Negative Bacteria/radiation effects , Gram-Positive Bacteria/radiation effects , Humans , Models, Theoretical , Ultraviolet Rays
8.
Environ Sci Technol ; 56(7): 4295-4304, 2022 Apr 05.
Article in English | MEDLINE | ID: covidwho-1735181

ABSTRACT

To address the challenge of the airborne transmission of SARS-CoV-2, photosensitized electrospun nanofibrous membranes were fabricated to effectively capture and inactivate coronavirus aerosols. With an ultrafine fiber diameter (∼200 nm) and a small pore size (∼1.5 µm), optimized membranes caught 99.2% of the aerosols of the murine hepatitis virus A59 (MHV-A59), a coronavirus surrogate for SARS-CoV-2. In addition, rose bengal was used as the photosensitizer for membranes because of its excellent reactivity in generating virucidal singlet oxygen, and the membranes rapidly inactivated 97.1% of MHV-A59 in virus-laden droplets only after 15 min irradiation of simulated reading light. Singlet oxygen damaged the virus genome and impaired virus binding to host cells, which elucidated the mechanism of disinfection at a molecular level. Membrane robustness was also evaluated, and in general, the performance of virus filtration and disinfection was maintained in artificial saliva and for long-term use. Only sunlight exposure photobleached membranes, reduced singlet oxygen production, and compromised the performance of virus disinfection. In summary, photosensitized electrospun nanofibrous membranes have been developed to capture and kill airborne environmental pathogens under ambient conditions, and they hold promise for broad applications as personal protective equipment and indoor air filters.


Subject(s)
COVID-19 , Nanofibers , Animals , COVID-19/prevention & control , Disinfection , Light , Mice , SARS-CoV-2
9.
BMC Infect Dis ; 22(1): 234, 2022 Mar 07.
Article in English | MEDLINE | ID: covidwho-1731520

ABSTRACT

BACKGROUND: Ozone (O3) is an effective disinfectant agent that leaves no harmful residues. Due to the global health crisis caused by the COVID-19 pandemic, surgical masks are in high demand, with some needing to be reused in certain regions. This study aims to evaluate the effects of O3 for pathogen disinfection on reused surgical masks in various conditions. METHODS: O3 generators, a modified PZ 2-4 for Air (2000 mg O3/L) and a modified PZ 7 -2HO for Air (500 mg O3/L), were used together with 1.063 m3 (0.68 × 0.68 × 2.3 m) and 0.456 m3 (0.68 × 0.68 × 1.15 m) acrylic boxes as well as a room-sized 56 m3 (4 × 4 × 3.5 m) box to provide 3 conditions for the disinfection of masks contaminated with enveloped RNA virus (105 FFU/mL), bacteria (103 CFU/mL) and fungi (102 spores/mL). RESULTS: The virucidal effects were 82.99% and 81.70% after 15 min of treatment with 2000 mg/L O3 at 1.063 m3 and 500 mg/L O3 at 0.456 m3, respectively. The viral killing effect was increased over time and reached more than 95% after 2 h of incubation in both conditions. By using 2000 mg/L O3 in a 1.063 m3 box, the growth of bacteria and fungi was found to be completely inhibited on surgical masks after 30 min and 2 h of treatment, respectively. Using a lower-dose O3 generator at 500 mg O3/L in 0.456 m3 provided lower efficiency, although the difference was not significant. Using O3 at 2000 mg O3/L or 500 mg O3/L in a 56 m3 room is efficient for the disinfection of all pathogens on the surface of reused surgical masks. CONCLUSIONS: This study provided the conditions for using O3 (500-2000 mg/L) to reduce pathogens and disinfect contaminated surgical masks, which might be applied to reduce the inappropriate usage of reused surgical masks.


Subject(s)
COVID-19 , Ozone , Disinfection , Humans , Ozone/pharmacology , Pandemics , SARS-CoV-2
10.
J Hosp Infect ; 122: 168-172, 2022 Apr.
Article in English | MEDLINE | ID: covidwho-1729912

ABSTRACT

BACKGROUND: The global COVID-19 pandemic, accompanied by spikes in the number of patients in hospitals, required substantial amounts of respiratory protective devices (respirators), thereby causing shortages. Disinfection of used respirators by applying ultraviolet C (UVC) light may enable safe reuse, reducing shortages. AIM: To determine whether UVC disinfection is applicable to enable repeated safe reuse of respirators. METHODS: The UVC chamber, equipped with low-pressure mercury discharge lamps emitting at 254 nm, was used to determine the sporicidal and virucidal effects. Respirators challenged with spores and viruses were exposed to various UVC energy levels. Deactivation of the biological agents was studied as well as UVC effects on particle filtration properties and respirator fit. FINDINGS: A 5 log10 reduction of G. thermophilus spore viability by a UVC dose of 1.1 J/cm2 was observed. By simulating spores present in the middle of the respirators, a 5 log10 reduction was achieved at a UVC dose of 10 J/cm2. SARS-CoV-2 viruses were inactivated by 4 log10 upon exposure to 19.5 mJ/cm2 UVC. In case UVC must be transmitted through all layers of the respirators to reach the spores and virus, a reduction of >5 log10 was achieved using a UVC dose of 10 J/cm2. Exposure to a six-times higher UVC dose did not significantly affect the integrity of the fit nor aerosol filtering capacity of the respirator. CONCLUSION: UVC was shown to be a mild and effective way of respirator disinfection allowing for reuse of the UVC-treated respirators.


Subject(s)
COVID-19 , SARS-CoV-2 , COVID-19/prevention & control , Decontamination , Disinfection , Equipment Reuse , Geobacillus stearothermophilus , Humans , Pandemics , Spores, Bacterial , Ultraviolet Rays , Ventilators, Mechanical
11.
J Microbiol Immunol Infect ; 55(1): 166-169, 2022 Feb.
Article in English | MEDLINE | ID: covidwho-1700704

ABSTRACT

This was a preliminary study on ultraviolet C (UVC) irradiation for SARS-CoV-2-contaminated hospital environments. Forty-eight locations were tested for SARS-CoV-2 using RT-PCR (33.3% contamination rate). After series dosages of 222-nm UVC irradiation, samples from the surfaces were negative at 15 s irradiation at 2 cm length (fluence: 81 mJ/cm2).


Subject(s)
COVID-19 , SARS-CoV-2 , Disinfection , Humans , Ultraviolet Rays , Virus Inactivation/radiation effects
12.
Am J Infect Control ; 50(3): 319-324, 2022 03.
Article in English | MEDLINE | ID: covidwho-1694005

ABSTRACT

BACKGROUND: The recent COVID-19 pandemic highlights the need for efficacious virucidal products to limit the spread of SARS-CoV-2. Several studies have suggested that alcohol-based sanitizers and some disinfectants are effective. While virucidal activity data of low-level disinfectants are lacking and some conclusions are not clear yet. METHODS: We evaluated the virucidal activity of 2 quaternary ammonium compounds (QAC) disinfectants (MICRO-CHEM PLUS and FWD), W30 (an amphoteric surfactant), and Medical EtOH against SARS-CoV-2. Suspension tests covering different concentration and contact time were performed using the integrated cell culture-qPCR method. RESULTS: Each of disinfectants was effective at inactivating SARS-CoV-2. MCP and FWD are highly effective within 15 seconds. W30 is also efficient within 2 minutes at concentration of 1%. Consistent with previous report, our results also demonstrated that 38% ethanol was sufficient to completely inactivate virus, which proved the method used in this study is feasible. CONCLUSIONS AND DISCUSSION: QAC disinfectants, MCP and FWD, are highly effective for the inactivation of SARS-CoV-2, which making them practical for use in health care setting and laboratories where prompt disinfection is important. The low-level disinfectant based on amphoteric surfactant, W30, which may present in commonly available household hygiene agents is also able to inactivate SARS-CoV-2.


Subject(s)
COVID-19 , Disinfectants , COVID-19/prevention & control , Disinfectants/pharmacology , Disinfection/methods , Humans , Pandemics , SARS-CoV-2
13.
Virol J ; 19(1): 29, 2022 02 10.
Article in English | MEDLINE | ID: covidwho-1690906

ABSTRACT

Ultraviolet (UV) light has previously been established as useful method of disinfection, with demonstrated efficacy to inactivate a broad range of microorganisms. The advent of ultraviolet light-emitting diodes provides advantages in ease of disinfection, in that there can be delivery of germicidal UV with the same light unit that delivers standard white light to illuminate a room. Herein we demonstrate the efficacy and feasibility of ultraviolet light-emitting diodes as a means of decontamination by inactivating two distinct virus models, human coronavirus 229E and human immunodeficiency virus. Importantly, the same dose of ultraviolet light that inactivated human viruses also elicited complete inactivation of ultraviolet-resistant bacterial spores (Bacillus pumilus), a gold standard for demonstrating ultraviolet-mediated disinfection. This work demonstrates that seconds of ultraviolet light-emitting diodes (UV-LED) exposure can inactivate viruses and bacteria, highlighting that UV-LED could be a useful and practical tool for broad sanitization of public spaces.


Subject(s)
Coronavirus 229E, Human , Disinfection , HIV-1 , Ultraviolet Rays , Virus Inactivation/radiation effects , Coronavirus 229E, Human/radiation effects , Disinfection/methods , HIV-1/radiation effects , Humans
14.
Front Public Health ; 9: 825468, 2021.
Article in English | MEDLINE | ID: covidwho-1686580

ABSTRACT

In the pandemic of COVID-19, it is crucial to consider the hygiene of the edible and nonedible things as it could be dangerous for our health to consume infected things. Furthermore, everything cannot be boiled before eating as it can destroy fruits and essential minerals and proteins. So, there is a dire need for a smart device that could sanitize edible items. The Germicidal Ultraviolet C (UVC) has proved the capabilities of destroying viruses and pathogens found on the surface of any objects. Although, a few minutes exposure to the UVC can destroy or inactivate the viruses and the pathogens, few doses of UVC light may damage the proteins of edible items and can affect the fruits and vegetables. To this end, we have proposed a novel design of a device that is employed with Artificial Intelligence along with UVC to auto detect the edible items and act accordingly. This causes limited UVC doses to be applied on different items as detected by proposed model according to their permissible limit. Additionally, the device is employed with a smart architecture which leads to consistent distribution of UVC light on the complete surface of the edible items. This results in saving the health as well as nutrition of edible items.


Subject(s)
COVID-19 , Disinfection , Artificial Intelligence , Humans , SARS-CoV-2 , Ultraviolet Rays/adverse effects
15.
Int J Environ Res Public Health ; 19(3)2022 01 21.
Article in English | MEDLINE | ID: covidwho-1650893

ABSTRACT

Interrupting the transmission of airborne (<≈5 µm) respiratory pathogens indoors is not a new challenge, but it has attracted unprecedented interest due to the COVID-19 pandemic during 2020-2021. However, bacterial respiratory pathogens with known or potential airborne transmission account for an appreciable proportion of the communicable disease burden globally. We aimed to systematically review quantitative, laboratory-based studies of air disinfection techniques for airborne respiratory bacteria. Three databases (PubMed, Web of Science, Scopus) were searched, following PRISMA guidelines. A total of 9596 articles were identified, of which 517 were assessed in detail and of which 26 met the inclusion and quality assessment criteria. Seven air disinfection techniques, including UV-C light, filtration, and face masks, among others, were applied to 13 different bacterial pathogens. More than 80% of studies suggested that air disinfection techniques were more effective at inactivating or killing bacteria than the comparator or baseline condition. However, it was not possible to compare these techniques because of methodological heterogeneity and the relatively small number of the studies. Laboratory studies are useful for demonstrating proof-of-concept and performance under controlled conditions. However, the generalisability of their findings to person-to-person transmission in real-world settings is unclear for most of the pathogens and techniques we assessed.


Subject(s)
Air Pollution, Indoor , COVID-19 , Air Microbiology , Bacteria , Disinfection , Humans , Pandemics , SARS-CoV-2
16.
Langmuir ; 38(6): 2162-2173, 2022 02 15.
Article in English | MEDLINE | ID: covidwho-1671480

ABSTRACT

According to both the Center for Disease Control and the World Health Organization, contact transmission is the primary transmission route of infectious diseases worldwide. Usually, this is mitigated by a schedule of repeated regular sanitization, yet surfaces are easily re-contaminated in the interim between cleanings. One solution to this problem is to generate self-disinfecting surfaces that can display sustained virucidal/antimicrobial properties against pathogens that settle upon them. Quaternary ammonium organosilicon compounds are ideal candidates to achieve this; cationic surfactants are safe and well-established surface disinfectants, while organosilanes are used broadly to form durable coatings with altered surface properties on many different materials. Despite their potential to circumvent the disadvantages of traditional disinfection methods, extant commercially available quaternary ammonium silanes do not display comparable efficacy to the standard surface disinfectants, nor have their respective coatings been demonstrated to meet the Environmental Protection Agency's guidelines for residual/extended efficacy. Inspired by the powerful surface activity of double-headed "gemini" surfactants, here, we present gemini-diquaternary silanes (GQs) with robust residual germicidal efficacy on various surfaces by incorporating a second cationic "head" to the structure of a conventional monoquaternary ammonium silane (MQ). Aqueous solutions of GQs were tested in suspension- and surface-antimicrobial assays against an array of pathogens, including Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). GQ performance was benchmarked against the common disinfectants, ethanol, hydrogen peroxide, hypochlorite, as well as MQ. Solutions of GQs were efficacious when used for immediate disinfection (>106-fold reduction in 15 s). Additionally, GQs were demonstrated to impart durable self-disinfecting properties to a variety of porous and nonporous surfaces, effective after repeated cycles of abrasion and repeated contaminations, and with superior coating ability and activity (>108 higher activity) than that of MQs. GQs as surface treatments show great promise to overcome the limitations of traditional disinfectants in preventing the spread of infectious diseases.


Subject(s)
COVID-19 , Communicable Diseases , Disinfectants , Disinfectants/toxicity , Disinfection/methods , Humans , SARS-CoV-2 , United States
17.
J Hazard Mater ; 430: 128414, 2022 05 15.
Article in English | MEDLINE | ID: covidwho-1665174

ABSTRACT

Coronavirus disease 2019 (COVID-19) has become a worldwide public health emergency, and the high transmission of SARS-CoV-2 variants has raised serious concerns. Efficient disinfection methods are crucial for the prevention of viral transmission. Herein, pulse power-driven cold atmospheric plasma (CAP), a novel sterilization strategy, was found to potently inactivate SARS-CoV-2-like coronavirus GX_P2V, six strains of major epidemic SARS-CoV-2 variants and even swine coronavirus PEDV and SADS-CoV within 300 s (with inhibition rate more than 99%). We identified four dominant short-lived reactive species, ONOO-, 1O2, O2- and·OH, generated in response to CAP and distinguished their roles in the inactivation of GX_P2V and SARS-CoV-2 spike protein receptor binding domain (RBD), which is responsible for recognition and binding to human angiotensin-converting enzyme 2 (hACE2). Our study provides detailed evidence of a novel surface disinfection strategy for SARS-CoV-2 and other coronaviruses.


Subject(s)
COVID-19 , Plasma Gases , Animals , COVID-19/prevention & control , Disinfection , Humans , Protein Binding , SARS-CoV-2 , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/metabolism , Swine
18.
J Environ Manage ; 308: 114617, 2022 Apr 15.
Article in English | MEDLINE | ID: covidwho-1665169

ABSTRACT

Nanotechnology holds huge potential for the prevention of various viral outbreaks that have increased at a disquieting rate over the past decades. Metal oxide nanomaterials with oxidative capability are the effective materials that provide platforms as well as tools for the well understanding of the mechanism, its detection, and treatment of various viral diseases like measles, influenza, herpes, ebola, current COVID-19 etc. In this inclusive review, we survey various previous research articles on different notable photoactive transition metal oxides that possess enough potential to act as antiviral agents for the deactivation of harmful viruses. We investigated and highlighted the plausible photocatalytic oxidative mechanism of photoactive transition metal oxides in degrading viral coatings, genomic RNA using suitable free radical generation. The key finding of the present review article including the discovery of a vision on the suitable photocatalytic transition metal oxides that have been proven to be excellent against harmful viruses and consequently combatting deadly CoV-2 in the environment. This review intends to provide conclusive remarks and a realistic outlook on other advanced photocatalytic metal oxides as a potential solution in battling other similar upcoming pandemics.


Subject(s)
COVID-19 , Viruses , Disinfection , Humans , Oxides , SARS-CoV-2
19.
Environ Pollut ; 292(Pt B): 118429, 2022 Jan 01.
Article in English | MEDLINE | ID: covidwho-1664902

ABSTRACT

Massive additional quantities of disinfectants have been applied during the COVID-19 pandemic as infection preventive and control measures. While the application of disinfectants plays a key role in preventing the spread of SARS-CoV-2 infection, the effects of disinfectants applied during the ongoing pandemic on non-target organisms remain unknown. Here we collated evidence from multiple studies showing that chemicals used for major disinfectant products can induce hormesis in various organisms, such as plants, animal cells, and microorganisms, when applied singly or in mixtures, suggesting potential ecological risks at sub-threshold doses that are normally considered safe. Among other effects, sub-threshold doses of disinfectant chemicals can enhance the proliferation and pathogenicity of pathogenic microbes, enhancing the development and spread of drug resistance. We opine that hormesis should be considered when evaluating the effects and risks of such disinfectants, especially since the linear-no-threshold (LNT) and threshold dose-response models cannot identify or predict their effects.


Subject(s)
COVID-19 , Disinfectants , Animals , Disinfection , Hormesis , Humans , Pandemics , SARS-CoV-2
20.
Am J Infect Control ; 50(4): 462-464, 2022 Apr.
Article in English | MEDLINE | ID: covidwho-1653967

ABSTRACT

We evaluated the effect of terminal cleaning on SARS-CoV-2 RNA contamination of COVID-19 isolation rooms in an acute care hospital. SARS-CoV-2 RNA was detected on 32.1% of room surfaces after cleaning; the odds of contamination increased with month. The prevalence of elevated high-touch surface contamination was lower in terminally cleaned rooms than patient-occupied rooms.


Subject(s)
COVID-19 , Disinfection , COVID-19/prevention & control , Hospitals , Humans , Patients' Rooms , RNA, Viral/genetics , SARS-CoV-2
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