Project description:Since the emergence of Middle East respiratory syndrome coronavirus (MERS-CoV) in mid-2012, there has been controversy over the respiratory precaution recommendations in different guidelines from various international bodies. Our understanding of MERS-CoV is still evolving. Current recommendations on infection control practices are heavily influenced by the lessons learnt from severe acute respiratory syndrome. A debate on respiratory precautions for MERS-CoV was organised by Infection Control Association (Singapore) and the Society of Infectious Disease (Singapore). We herein discuss and present the evidence for surgical masks for the protection of healthcare workers from MERS-CoV.
Project description:BackgroundRecently, several randomized controlled trials (RCTs) have evaluated the effect of N95 respirators compared with medical masks to protect against acute respiratory infections. However, these studies are limited by modest sample sizes and inconclusive results. Therefore, the goal of the present study was to review the relevant and available published RCTs with the aid of the increased power of meta-analytic methods in order to assess the effectiveness of medical masks and N95 respirators in reducing the risk of respiratory infections.MethodsThis meta-analysis follows the recommendations of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement for conducting and reporting results. We searched PubMed, Web of Science, Embase, and Cochrane databases from inception through April 1, 2020 to identify potentially relevant studies. Two authors (LS and JS) independently searched the titles and abstracts of the potentially eligible articles. They independently retrieved required data from the eligible trials; the data were initially tabulated for statistical analysis. Two authors (JRL and LS) independently assessed the methodological quality of the included RCTs using the Cochrane Collaboration's tool for assessing risk of bias.ResultsSix articles met the inclusion criteria. The pooled analysis showed that N95 respirators did not reduce the risk of infection with respiratory viruses compared with medical/surgical masks (5.7% vs. 7.9%; RR = 1.12; 95% CI: 0.88-1.41; p = 0.36); however, there was no statistically significant difference in laboratory-confirmed influenza between N95 and medical masks (RR = 0.91; 95% CI: 0.77-1.07; p = 0.26). Medical masks provided similar protection against other viruses, including coronavirus (RR = 0.74; 95% CI: 0.32-1.73; p = 0.49). Respiratory illness, as well as influenza-like illness were less frequently observed with N95 respirators.ConclusionsOur meta-analysis suggests that there are insufficient data to definitively determine whether N95 respirators are superior to medical masks in protection against transmissible acute respiratory infections. Further randomized trials are necessary to compare the above methods of respiratory protection in the context of COVID-19 incidence.
Project description:ObjectivesThis scoping review aimed to map and compile the available evidence regarding the effectiveness of decontaminating N95 respirators against the novel coronavirus (SARS-CoV-2).DataWe selected studies written in English assessing or discussing the decontamination strategies of N95 respirators against SARS-CoV-2. Two independent researchers performed the search and study screening. A descriptive analysis was carried out considering the study design of the included studies.SourcesPubMed, SCOPUS, and Preprint platforms (bioRxiv and medRxiv).Study selectionWe included 55 reports from PubMed and SCOPUS. Nine articles were letters to the editors, 21 were in vitro studies, 16 were literature reviews, and 9 were classified as other study designs. We included 37 preprints. Two articles were letters to the editors, 24 were in vitro studies, 3 were literature reviews, and 8 were classified as other study designs. In general, vaporized hydrogen peroxide and ultraviolet irradiation were the strategies most cited and most promising. However, there is a lack of evidence and consensus related to the best method of N95 respirator decontamination.ConclusionThe evidence regarding decontamination strategies of N95 respirators against SARS-CoV-2 remains scarce. Vaporized hydrogen peroxide and ultraviolet irradiation seem to be the current standard for N95 respirator decontamination.Clinical significanceVaporized hydrogen peroxide and ultraviolet irradiation appear to be the most promising methods for N95 respirator decontamination.
Project description:As part of efforts to combat the Covid-19 pandemic and decrease the high transmissibility of the new coronavirus, SARS-CoV-2, effective inactivation strategies, such as UV-C decontamination technologies, can be reliably disseminated and well-studied. The present study investigated the susceptibility of a high viral load of SARS-CoV-2 in filtering facepiece respirators (FFR) N95, surgical mask, cotton fabric mask and N95 straps under three different doses of UV-C, applying both real-time PCR (qPCR) and plaque formation assays to quantify viral load reduction and virus infectivity, respectively. The results show that more than 95% of the amount of SARS-CoV-2 RNA could be reduced after 10 min of UV-C exposure (0.93 J cm-2 per side) in FFR N95 and surgical masks and, after 5 min of UV-C treatment (0.46 J cm-2 per side) in fabric masks. Furthermore, the analysis of viable coronaviruses after these different UV-C treatments demonstrated that the lowest applied dose is sufficient to decontaminate all masks ([Formula: see text] 3-log10 reduction of the infective viral load, > 99.9% reduction). However, for the elastic strap of N95 respirators, a UV-C dose three times greater than that used in masks (1.4 J cm-2 per side) is required. The findings suggest that the complete decontamination of masks can be performed effectively and safely in well-planned protocols for pandemic crises or as strategies to reduce the high consumption and safe disposal of these materials in the environment.
Project description:ObjectivesSurgical masks and N95 filtering facepiece respirators (FFRs) prevent the spread of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection and protect medical personnel. Increased demands for surgical masks and N95 FFRs during the coronavirus disease 2019 (COVID-19) pandemic has resulted in the shortage crisis. However, there is no standard protocol for safe reuse of the N95 FFRs. In this systematic review, we aimed to evaluate the effectiveness of existing decontamination methods of surgical masks and N95 FFRs and provide evidence-based recommendations for selecting an appropriate decontamination method.MethodsWe performed systematic searches of Ovid MEDLINE and Ovid EMBASE electronic databases. The last search was performed April 11, 2020. Any trials studying surgical masks and/or N95 FFRs decontamination were included. Outcomes were disinfections of virus and bacteria, restoration of the filtration efficiency, and maintenance of the physical structure of the mask.ResultsOverall, 15 studies and 14 decontamination methods were identified. A low level of evidence supported 4 decontamination methods: ultraviolet (UV) germicidal irradiation (9 studies), moist heat (5 studies), microwave-generated steam (4 studies), and hydrogen peroxide vapor (4 studies). Therefore, we recommended these 4 methods, and we recommended against use were given for the other 10 methods.ConclusionsA low level of evidence supported the use of UV germicidal irradiation, moist heat, microwave-generated steam, and hydrogen peroxide vapor for decontamination and reuse of N95 FFRs. These decontamination methods were effective for viral and bacterial disinfection as well as restoration of the filtration efficiency, and the physical structure of the FFRs.
Project description:BackgroundIn the context of the COVID-19 pandemic, cases of adverse skin reactions related to the wearing of masks have been observed.ObjectivesTo analyze the short-term effects of N95 respirators and medical masks, respectively, on skin physiological properties and to report adverse skin reactions caused by the protective equipment.MethodsThis study used a randomized crossover design with repeated measurements. Twenty healthy Chinese volunteers were recruited. Skin parameters were measured on areas covered by the respective masks and on uncovered skin 2 and 4 hours after donning, and 0.5 and 1 hour after removing the masks, including skin hydration, transepidermal water loss (TEWL), erythema, pH, and sebum secretion. Adverse reactions were clinically assessed, and perceived discomfort and non-compliance measured.ResultsSkin hydration, TEWL, and pH increased significantly with wearing the protective equipment. Erythema values increased from baseline. Sebum secretion increased both on the covered and uncovered skin with equipment-wearing. There was no significant difference in physiological values between the two types of equipment. More adverse reactions were reported following a N95 mask use than the use of a medical mask, with a higher score of discomfort and non-compliance.ConclusionsThis study demonstrates that skin biophysical characters change as a result of wearing a mask or respirator. N95 respirators were associated with more skin reactions than medical masks.
Project description:AimsAssess the feasibility of using light from artificial sun lamps to decontaminate N95 filtering facepiece respirators (FFRs) contaminated with SARS-CoV-2.Methods and resultsFFR coupons or whole FFRs contaminated with 5 log10 TCID50 (target concentration) SARS-CoV-2 in culture media, simulated saliva, or simulated lung fluid were dried for 1-2 h, then exposed to light from tanning and horticulture lamps to assess decontamination. Exposed coupons and whole FFRs showed SARS-CoV-2 inactivation for all matrices tested. Furthermore, FFRs still met performance specifications after five decontamination cycles.ConclusionsIt is feasible that artificial sunlight from these sun lamps can be used to decontaminate FFRs provided the UV dose is sufficient and the light is unobstructed. Furthermore, decontamination can be performed up to five times without degrading FFR performance.Significance and impact of the studyThis research shows a proof of principle that artificial sun lamps may be an option to decontaminate SARS-CoV-2 on N95 FFRs. UV doses required for inactivation to levels below detection ranged from 4 to 37·8 J cm-2 depending on the light source, virus matrix and FFR type.
Project description:BackgroundThe efficacy of barrier precautions to prevent influenza transmission is unknown.MethodsTwenty-eight participants were exposed to monodispersed live attenuated influenza vaccine (LAIV) particles (4.9 μm) in 6 groups: group 1, no precautions; group 2, ocular exposure only; group 3, surgical mask without eye protection; group 4, surgical mask with eye protection; group 5, fit-tested N95 respirator without eye protection; and group 6, fit-tested N95 respirator with eye protection. Influenza was detected by reverse-transcription polymerase chain reaction (RT-PCR) and culture in nasal washes. Exact 95% confidence intervals (CIs) were calculated.ResultsInfluenza was detected in 4 of 4 participants in group 1 (95% CI, 0-.60), 3 of 4 in group 2 (95% CI, .006-.806]), 5 of 5 in group 3 (95% CI, 0-.522), 5 of 5 in group 4, (95% CI, 0-.522), 3 of 5 in group 5 (95% CI, .053-.853), and 1 of 5 in group 6 (95% CI, .05-.72). RT-PCR revealed significant differences between group 1 and all other groups except group 3.ConclusionsTransocular transmission of LAIV occured in most participants suggesting the necessity of eye protection. An N95 respirator provided the best guard further enhanced by eye protection.
Project description:Face coverings are a key component of preventive health measure strategies to mitigate the spread of respiratory illnesses. In this study five groups of masks were investigated that are of particular relevance to the SARS-CoV-2 pandemic: re-usable, fabric two-layer and multi-layer masks, disposable procedure/surgical masks, KN95 and N95 filtering facepiece respirators. Experimental work focussed on the particle penetration through mask materials as a function of particle diameter, and the total inward leakage protection performance of the mask system. Geometric mean fabric protection factors varied from 1.78 to 144.5 for the fabric two-layer and KN95 materials, corresponding to overall filtration efficiencies of 43.8% and 99.3% using a flow rate of 17 L/min, equivalent to a breathing expiration rate for a person in a sedentary or standing position conversing with another individual. Geometric mean total inward leakage protection factors for the 2-layer, multi-layer and procedure masks were <2.3, while 6.2 was achieved for the KN95 masks. The highest values were measured for the N95 group at 165.7. Mask performance is dominated by face seal leakage. Despite the additional filtering layers added to cloth masks, and the higher filtration efficiency of the materials used in disposable procedure and KN95 masks, the total inward leakage protection factor was only marginally improved. N95 FFRs were the only mask group investigated that provided not only high filtration efficiency but high total inward leakage protection, and remain the best option to protect individuals from exposure to aerosol in high risk settings. The Mask Quality Factor and total inward leakage performance are very useful to determine the best options for masking. However, it is highly recommended that testing is undertaken on prospective products, or guidance is sought from impartial authorities, to confirm they meet any implied standards.
Project description:ObjectivesThere are currently no studies that have examined whether one dosage can be uniformly applied to different respirator types to effectively decontaminate SARS-CoV-2 on N95 filtering facepiece respirators (FFRs). Health care workers have been using this disinfection method during the pandemic. Our objective was to determine the effect of UVC on SARS-CoV-2 inoculated N95 respirators and whether this was respirator material/model type dependent.MethodsFour different locations (facepiece and strap) on five different N95 FFR models (3M 1860, 8210, 8511, 9211; Moldex 1511) were inoculated with a 10 μL drop of SARS-CoV-2 viral stock (8 × 107 TCID50/mL). The outside-facing and wearer-facing surfaces of the respirators were each irradiated with a dose of 1.5 J/cm2 UVC (254 nm). Viable SARS-CoV-2 was quantified by a median tissue culture infectious dose assay (TCID50).ResultsUVC delivered using a dose of 1.5 J/cm2, to each side, was an effective method of decontamination for the facepieces of 3M 1860 and Moldex 1511, and for the straps of 3M 8210 and the Moldex 1511.ConclusionThis dose is an appropriate decontamination method to facilitate the reuse of respirators for healthcare personnel when applied to specific models/materials. Also, some straps may require additional disinfection to maximize the safety of frontline workers. Implementation of widespread UVC decontamination methods requires careful consideration of model, material type, design, and fit-testing following irradiation.