Protecting healthcare workers from pandemic influenza: N95 or surgical masks?:

Bioprotective Respirator Assembled by Defective Carbon Nitride for Long-Term Light Triggered Health Protection

Wearing face masks is the best way to stop the spread of respiratory infections. However, if masks are not sterilized, changing them too frequently can actually increase the risk of cross-contamination. Herein, the construction of an antipathogen photocatalytic mask with carbon vacancy-modified carbon nitride nanosheets (g-C3N4-VC Ns) coated on the non-woven fabrics of the out layer of the mask, offering effective and long-term protection against damaging pathogens when exposed to light is reported. The introduced carbon vacancies are found capable of creating energy-disordered sites and inducing energetic electric force to overcome the Coulomb interactions between electron-hole pairs, thus promoting the electron-hole separation to achieve a high generation of reactive oxygen species (ROS). Thanks to its high activity in generating ROS upon exposure to light, the as-prepared photocatalytic mask shows high pathogen sterilization performance. This, in turn, prolongs the mask's protective lifetime, decreases the need for regular replacement, and decreases medical waste production. The work demonstrated here opens new viewpoints in designing pathogens biocidal protective devices for health protection, offering significant promise in specific environment self-protection.

Nanoscale hyperthermia mesostructures for sustainable antimicrobial design

Sustainability is critical in addressing global challenges posed by prolonged pandemics that impact health, economies, and the environment. Here, we introduce a molecular engineering approach for thermoregulated antimicrobial management inspired by firewalking rituals. The study uses in situ spectroscopy and multi-scale modeling to validate a hierarchical design. Efficient light-to-thermal energy conversion is achieved by engineering the molecular band structure. Rapid nanoscale hyperthermia is facilitated through thermal engineering. This approach significantly reduces the half-life of pathogens such as Escherichia coli, influenza A, and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) to 1.4 min while maintaining a low perceived temperature on human skin. Standard disease infection and epidemic models show this technology's potential to flatten outbreak curves and delay peak infection rates, which is crucial during the early stages of pandemics when developing vaccines and antiviral drugs takes time. The scalable manufacturing and broad antimicrobial applicability hold great promise for controlling emerging infectious diseases and diverse bioprotective applications.

Wearing face masks as a potential source for inhalation and oral uptake of inanimate toxins - A scoping review

BACKGROUND

From 2020 to 2023 many people around the world were forced to wear masks for large proportions of the day based on mandates and laws. We aimed to study the potential of face masks for the content and release of inanimate toxins.

METHODS

A scoping review of 1003 studies was performed (database search in PubMed/MEDLINE, qualitative and quantitative evaluation).

RESULTS

24 studies were included (experimental time 17 min to 15 days) evaluating content and/or release in 631 masks (273 surgical, 228 textile and 130 N95 masks). Most studies (63%) showed alarming results with high micro- and nanoplastics (MPs and NPs) release and exceedances could also be evidenced for volatile organic compounds (VOCs), xylene, acrolein, per-/polyfluoroalkyl substances (PFAS), phthalates (including di(2-ethylhexyl)-phthalate, DEHP) and for Pb, Cd, Co, Cu, Sb and TiO2.

DISCUSSION

Of course, masks filter larger dirt and plastic particles and fibers from the air we breathe and have specific indications, but according to our data they also carry risks. Depending on the application, a risk-benefit analysis is necessary.

CONCLUSION

Undoubtedly, mask mandates during the SARS-CoV-2 pandemic have been generating an additional source of potentially harmful exposition to toxins with health threatening and carcinogenic properties at population level with almost zero distance to the airways.

Possible toxicity of chronic carbon dioxide exposure associated with face mask use, particularly in pregnant women, children and adolescents - A scoping review

Introduction

During the SARS-CoV-2-pandemic, face masks have become one of the most important ubiquitous factors affecting human breathing. It increases the resistance and dead space volume leading to a re-breathing of CO2. So far, this phenomenon and possible implications on early life has not been evaluated in depth.

Method

As part of a scoping review, literature was systematically reviewed regarding CO2 exposure and facemask use.

Results

Fresh air has around 0.04% CO2, while wearing masks more than 5 min bears a possible chronic exposure to carbon dioxide of 1.41% to 3.2% of the inhaled air. Although the buildup is usually within the short-term exposure limits, long-term exceedances and consequences must be considered due to experimental data. US Navy toxicity experts set the exposure limits for submarines carrying a female crew to 0.8% CO2 based on animal studies which indicated an increased risk for stillbirths. Additionally, mammals who were chronically exposed to 0.3% CO2 the experimental data demonstrate a teratogenicity with irreversible neuron damage in the offspring, reduced spatial learning caused by brainstem neuron apoptosis and reduced circulating levels of the insulin-like growth factor-1. With significant impact on three readout parameters (morphological, functional, marker) this chronic 0.3% CO2 exposure has to be defined as being toxic. Additional data exists on the exposure of chronic 0.3% CO2 in adolescent mammals causing neuron destruction, which includes less activity, increased anxiety and impaired learning and memory. There is also data indicating testicular toxicity in adolescents at CO2 inhalation concentrations above 0.5%.

Discussion

There is a possible negative impact risk by imposing extended mask mandates especially for vulnerable subgroups. Circumstantial evidence exists that extended mask use may be related to current observations of stillbirths and to reduced verbal motor and overall cognitive performance in children born during the pandemic. A need exists to reconsider mask mandates.

Physical interventions to interrupt or reduce the spread of respiratory viruses

BACKGROUND

Viral epidemics or pandemics of acute respiratory infections (ARIs) pose a global threat. Examples are influenza (H1N1) caused by the H1N1pdm09 virus in 2009, severe acute respiratory syndrome (SARS) in 2003, and coronavirus disease 2019 (COVID-19) caused by SARS-CoV-2 in 2019. Antiviral drugs and vaccines may be insufficient to prevent their spread. This is an update of a Cochrane Review last published in 2020. We include results from studies from the current COVID-19 pandemic.

OBJECTIVES

To assess the effectiveness of physical interventions to interrupt or reduce the spread of acute respiratory viruses.

SEARCH METHODS

We searched CENTRAL, PubMed, Embase, CINAHL, and two trials registers in October 2022, with backwards and forwards citation analysis on the new studies.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and cluster-RCTs investigating physical interventions (screening at entry ports, isolation, quarantine, physical distancing, personal protection, hand hygiene, face masks, glasses, and gargling) to prevent respiratory virus transmission.  DATA COLLECTION AND ANALYSIS: We used standard Cochrane methodological procedures.

MAIN RESULTS

We included 11 new RCTs and cluster-RCTs (610,872 participants) in this update, bringing the total number of RCTs to 78. Six of the new trials were conducted during the COVID-19 pandemic; two from Mexico, and one each from Denmark, Bangladesh, England, and Norway. We identified four ongoing studies, of which one is completed, but unreported, evaluating masks concurrent with the COVID-19 pandemic. Many studies were conducted during non-epidemic influenza periods. Several were conducted during the 2009 H1N1 influenza pandemic, and others in epidemic influenza seasons up to 2016. Therefore, many studies were conducted in the context of lower respiratory viral circulation and transmission compared to COVID-19. The included studies were conducted in heterogeneous settings, ranging from suburban schools to hospital wards in high-income countries; crowded inner city settings in low-income countries; and an immigrant neighbourhood in a high-income country. Adherence with interventions was low in many studies. The risk of bias for the RCTs and cluster-RCTs was mostly high or unclear. Medical/surgical masks compared to no masks We included 12 trials (10 cluster-RCTs) comparing medical/surgical masks versus no masks to prevent the spread of viral respiratory illness (two trials with healthcare workers and 10 in the community). Wearing masks in the community probably makes little or no difference to the outcome of influenza-like illness (ILI)/COVID-19 like illness compared to not wearing masks (risk ratio (RR) 0.95, 95% confidence interval (CI) 0.84 to 1.09; 9 trials, 276,917 participants; moderate-certainty evidence. Wearing masks in the community probably makes little or no difference to the outcome of laboratory-confirmed influenza/SARS-CoV-2 compared to not wearing masks (RR 1.01, 95% CI 0.72 to 1.42; 6 trials, 13,919 participants; moderate-certainty evidence). Harms were rarely measured and poorly reported (very low-certainty evidence). N95/P2 respirators compared to medical/surgical masks We pooled trials comparing N95/P2 respirators with medical/surgical masks (four in healthcare settings and one in a household setting). We are very uncertain on the effects of N95/P2 respirators compared with medical/surgical masks on the outcome of clinical respiratory illness (RR 0.70, 95% CI 0.45 to 1.10; 3 trials, 7779 participants; very low-certainty evidence). N95/P2 respirators compared with medical/surgical masks may be effective for ILI (RR 0.82, 95% CI 0.66 to 1.03; 5 trials, 8407 participants; low-certainty evidence). Evidence is limited by imprecision and heterogeneity for these subjective outcomes. The use of a N95/P2 respirators compared to medical/surgical masks probably makes little or no difference for the objective and more precise outcome of laboratory-confirmed influenza infection (RR 1.10, 95% CI 0.90 to 1.34; 5 trials, 8407 participants; moderate-certainty evidence). Restricting pooling to healthcare workers made no difference to the overall findings. Harms were poorly measured and reported, but discomfort wearing medical/surgical masks or N95/P2 respirators was mentioned in several studies (very low-certainty evidence).  One previously reported ongoing RCT has now been published and observed that medical/surgical masks were non-inferior to N95 respirators in a large study of 1009 healthcare workers in four countries providing direct care to COVID-19 patients.  Hand hygiene compared to control Nineteen trials compared hand hygiene interventions with controls with sufficient data to include in meta-analyses. Settings included schools, childcare centres and homes. Comparing hand hygiene interventions with controls (i.e. no intervention), there was a 14% relative reduction in the number of people with ARIs in the hand hygiene group (RR 0.86, 95% CI 0.81 to 0.90; 9 trials, 52,105 participants; moderate-certainty evidence), suggesting a probable benefit. In absolute terms this benefit would result in a reduction from 380 events per 1000 people to 327 per 1000 people (95% CI 308 to 342). When considering the more strictly defined outcomes of ILI and laboratory-confirmed influenza, the estimates of effect for ILI (RR 0.94, 95% CI 0.81 to 1.09; 11 trials, 34,503 participants; low-certainty evidence), and laboratory-confirmed influenza (RR 0.91, 95% CI 0.63 to 1.30; 8 trials, 8332 participants; low-certainty evidence), suggest the intervention made little or no difference. We pooled 19 trials (71, 210 participants) for the composite outcome of ARI or ILI or influenza, with each study only contributing once and the most comprehensive outcome reported. Pooled data showed that hand hygiene may be beneficial with an 11% relative reduction of respiratory illness (RR 0.89, 95% CI 0.83 to 0.94; low-certainty evidence), but with high heterogeneity. In absolute terms this benefit would result in a reduction from 200 events per 1000 people to 178 per 1000 people (95% CI 166 to 188). Few trials measured and reported harms (very low-certainty evidence). We found no RCTs on gowns and gloves, face shields, or screening at entry ports.

AUTHORS' CONCLUSIONS

The high risk of bias in the trials, variation in outcome measurement, and relatively low adherence with the interventions during the studies hampers drawing firm conclusions. There were additional RCTs during the pandemic related to physical interventions but a relative paucity given the importance of the question of masking and its relative effectiveness and the concomitant measures of mask adherence which would be highly relevant to the measurement of effectiveness, especially in the elderly and in young children. There is uncertainty about the effects of face masks. The low to moderate certainty of evidence means our confidence in the effect estimate is limited, and that the true effect may be different from the observed estimate of the effect. The pooled results of RCTs did not show a clear reduction in respiratory viral infection with the use of medical/surgical masks. There were no clear differences between the use of medical/surgical masks compared with N95/P2 respirators in healthcare workers when used in routine care to reduce respiratory viral infection. Hand hygiene is likely to modestly reduce the burden of respiratory illness, and although this effect was also present when ILI and laboratory-confirmed influenza were analysed separately, it was not found to be a significant difference for the latter two outcomes. Harms associated with physical interventions were under-investigated. There is a need for large, well-designed RCTs addressing the effectiveness of many of these interventions in multiple settings and populations, as well as the impact of adherence on effectiveness, especially in those most at risk of ARIs.

A Review of Filtration Performance of Protective Masks

Masks are essential and effective small protective devices used to protect the general public against infections such as COVID-19. However, available systematic reviews and summaries on the filtration performance of masks are lacking. Therefore, in order to investigate the filtration performance of masks, filtration mechanisms, mask characteristics, and the relationships between influencing factors and protective performance were first analyzed through mask evaluations. The summary of filtration mechanisms and mask characteristics provides readers with a clear and easy-to-understand theoretical cognition. Then, a detailed analysis of influencing factors and the relationships between the influencing factors and filtration performance is presented in. The influence of the aerosol size and type on filtration performance is nonlinear and nonconstant, and filtration efficiency decreases with an increase in the gas flow rate; moreover, fitness plays a decisive role in the protective effects of masks. It is recommended that the public should wear surgical masks to prevent COVID-19 infection in low-risk and non-densely populated areas. Future research should focus on fitness tests, and the formulation of standards should also be accelerated. This paper provides a systematic review that will be helpful for the design of masks and public health in the future.

Vaccine or Garlic-Is It a Choice? Awareness of Medical Personnel on Prevention of Influenza Infections

BACKGROUND

Preventing the spread of the influenza virus is one of the primary health policy challenges of many countries worldwide. One of the more effective ways to prevent infection is influenza vaccination, and the people who enjoy the most public confidence in preventive health care are health workers (HWs). For this reason, it is crucial to study the attitudes of HWs toward influenza vaccination.

METHODS

The survey was conducted among 950 medical (physicians and nurses) and administrative staff in three academic hospitals. Respondents to the survey were selected on a random-target basis to represent hospital employees in the study best. The survey was conducted using the PAPI method between August and September 2020.

RESULTS

Respondents considered hand washing (52.8%) and avoiding contact with sick people (49.3%) the most effective ways to prevent influenza infection. Three in ten respondents considered wearing a protective mask (30.1%) and getting vaccinated against influenza (29.9%) is fully effective in preventing influenza. Influenza vaccination as effective in preventing influenza virus infection was chosen more often by those who worked in a pediatric hospital. Nurses were twice less likely than physicians to declare that influenza vaccination prevents infection (42.4% for nurses vs. 84.0% for physicians). At the same time, 20.4% of nurses believed that eating garlic effectively prevented influenza infection, and 28.1% declared daily vitamin C helpful.

CONCLUSIONS

The study pointed to significant educational gaps regarding the role and effectiveness of influenza vaccination in the process of influenza virus infection and indicated a firm belief in medical myths, especially in the nursing community, related to protection against influenza virus infection.

Listening Effort and Speech Perception Performance Using Different Facemasks

PURPOSE

The aim of this study was to assess the effect of eight different facemasks on speech perception and listening effort in listeners with normal hearing (NH) and hearing loss by manipulating both mask type and background noise levels.

METHOD

Forty adults listened to Quick Speech-in-Noise Test sentences recorded by a female talker through eight different facemasks including a baseline condition with no mask. Listeners were tested in the sound field positioned 6 ft from the loudspeaker. Signal-to-noise ratio (SNR) loss and listening effort were measured.

RESULTS

Listeners with NH exhibited a mild SNR loss, whereas those with hearing loss experienced a moderate SNR loss. Scores for the mild hearing loss group were significantly poorer (higher) than those with slight hearing loss. Speech perception performance was best in the no mask, KN95, and surgical mask conditions and poorest in the cloth mask and cloth mask plus face shield conditions for all groups. As listening effort decreased, speech perception increased for all groups.

CONCLUSIONS

The impact of different types of facemasks on speech perception in noise was demonstrated in this study indicating that as the SNR was reduced, listening effort increased and speech perception performance decreased for listeners with NH and slight/mild hearing loss. No mask, KN95, and surgical masks had the least impact on performance, whereas cloth masks posed a significant detriment to communication. If communication is to occur in a background of noise while wearing masks, a KN95 mask and an SNR of at least +15 dB is recommended regardless of hearing status.

Face masks to fight against COVID-19 pandemics: A comprehensive review of materials, design, technology and product development

The outbreak of COVID-19 has created renewed attention on research and large scale manufacturing of face masks. In the last two decades, usage of face masks for respiratory protection has gained increased importance as a measure to control the maladies and fatalities due to exposure to particulate pollutants and toxic pathogens. Numerous variants of surgical and high-performance respirator masks are available in the market, and yet the fibrous materials science researchers, manufacturers and public health agencies are making concerted efforts towards improvising them with respect to self-sterilisability, facial fit, thermo-physiological comfort, reusability and biodegradability, while maintaining or rather enhancing the filtration efficiency. This review article presents a compendium of materials, design and performance standards of existing face masks, as well as elaborates on developments made for their performance enhancement. The criticality of inculcation of good hygiene habits and earnest compliance to correct mask donning and doffing practices has also been highlighted. This review is expected to make valuable contributions in the present COVID-19 scenario when donning a face mask has become mandatory.

How to Make Personal Protective Equipment Spontaneously and Continuously Antimicrobial (Incorporating Oxidase-like Catalysts)

The inability of commercial personal protective equipment (PPE) to inactivate microbes in the droplets/aerosols they intercept makes used PPE a potential source of cross-contamination. To make PPE spontaneously and continuously antimicrobial, we incorporate PPE with oxidase-like catalysts, which efficiently convert O₂ into reactive oxygen species (ROS) without requiring any externally applied stimulus. Using a single-atom catalyst (SAC) nanoparticle containing atomically dispersed copper atoms as the reactive centers (Cu-SAC) and a silver-palladium bimetallic alloy nanoparticle (AgPd_0.38) as models for oxidase-like catalysts, we show that the incorporation of oxidase-like catalysts enables PPE to inactivate bacteria in the droplets/aerosols they intercept without requiring any externally applied stimulus. Notably, this approach works both for PPE that are fibrous and woven such as a commercial KN95 facial respirator and for those made of solid plastics such as an apron. This work suggests a feasible and global approach for preventing PPE from spreading infectious diseases.

Smart mask - Wearable IoT solution for improved protection and personal health

The use of face masks is an important way to fight the COVID-19 pandemic. In this paper, we envision the Smart Mask, an IoT supported platform and ecosystem aiming to prevent and control the spreading of COVID-19 and other respiratory viruses. The integration of sensing, materials, AI, wireless, IoT, and software will help the gathering of health data and health-related event detection in real time from the user as well as from their environment. In the larger scale, with the help of AI-based analysis for health data it is possible to predict and decrease medical costs with accurate diagnoses and treatment plans, where the comparison of personal data to large-scale public data enables drawing up a personal health trajectory, for example. Key research problems for smart respiratory protective equipment are identified in addition to future research directions. A Smart Mask prototype was developed with accompanying user application, backend and heath AI to study the concept.

Effectiveness of N95 Masks against SARS-CoV-2: Performance Efficiency, Concerns, and Future Directions

The coronavirus disease 2019 (COVID-19) epidemic, which is caused by novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has continued to spread around the world since December 2019. Healthcare workers and other medical first responders in particular need personal protective equipment to protect their respiratory system from airborne particulates, in addition to liquid splashes to the face. N95 respirator have become a critical component for reducing SARS-CoV-2 transmission and controlling the scale of the COVID-19 pandemic. However, a major dispute concerning the protective performance of N95 respirators has erupted, with a myriad of healthcare workers affected despite wearing N95 masks. This article reviews the most recent updates about the performance of N95 respirators in protecting against the SARS-CoV-2 virus in the present pandemic situation. A brief overview of the manufacturing methods, air filtration mechanisms, stability, and reusability of the mask is provided. A detailed performance evaluation of the mask is studied from an engineering point of view. This Review also reports on a comparative study about the protective performance of all commercially available surgical and respiratory masks used to combat the spread of COVID-19. With the aim of protecting healthcare providers more efficiently, we suggest some potential directions for the development of this respiratory mask that improve the performance efficiency of the mask.

Adherence to facemask use in public places during the autumn-winter 2020 COVID-19 lockdown in Greece: observational data

BACKGROUND

Wearing facemasks is of proven efficacy as a public health protective measure against COVID-19. Currently there are no observational data concerning the wearing of facemasks and the adherence to guidelines concerning their handling.

METHODS

Registration of the way passers-by were wearing facemasks at 26 different locations of five major cities in Greece. The results were correlated with the rate of COVID-19 deaths in the region.

RESULTS

In total, 119,433 passers-by were registered, 57,043 females (47.8%) and 62,390 males (52.2%). From the total sample, 81.1% were wearing the mask properly, 10.8% had their nose out, 6.2% were wearing it under the jaw, and 1.9% had no mask at all . There was a significant difference between males and females concerning any use of mask. Inappropriate use of was correlated with COVID-19 death rate in the studied region.

CONCLUSION

Our findings suggest that under conditions of mandatory wearing and in central locations of major cities, during walking, proper use of masks is suboptimal, but still contributes with some protection. Fear and risk perception seem to be strong factors contributing to adherence to proper mask wearing.

Contribution à l’étude de l’efficacité et de l’entretien des masques de protection respiratoire COVID en tissu fait maison

Le port du masque est devenu obligatoire pour le public dès la sortie de leur domicile. Aussi et souvent pour des raisons socioéconomiques, la fabrication artisanale en tissu est autorisée. Toutefois, autour de cette obligation à porter un masque, il existe actuellement de nombreuses carences en ce qui concerne les connaissances en matière de processus de confection et d’entretien de ces masques. Face à ces nombreuses incertitudes, la Société française de médecine de catastrophes a confié à l’Institut pour la maîtrise des risques (IMdR) le soin de conduire scientifiquement le projet de caractérisation de critères de performance de ces masques pouvant être confectionnés à domicile : choix de la forme adaptée (design) et de types de tissus, respirabilité, microbiologie, colmatage, congruence, fit-test, lavage, usage, entretien, rangement, etc. L’objectif visé est de renforcer la confiance du public quant à leur sentiment de protection par ce type de masque contre la COVID-19 grâce à la constitution d’une méthodologie d’évaluation pertinente, rigoureuse et reproductible.

Virucidal and biodegradable specialty cellulose nonwovens as personal protective equipment against COVID-19 pandemic

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Enable to instantly inactivate SARS-CoV-2 (>99.14%) and HCoV-229E (>98.83%).

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Excellent growth inhibition (>99.51%) towards both E. coli and S. aureus.

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Address the environmental concerns raised by non-biodegradable face masks.

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Development of safe, comfortable, and biodegradable textiles for PPE.

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A facile and scalable method to produce biocidal textiles for various applications.

Introduction

Face masks are regarded as effective Personal Protective Equipment (PPE) during the COVID-19 pandemic. However, the dominant polypropylene (PP)-based masks are devoid of antiviral/antibacterial activities and create enormous environmental burdens after disposal.

Objectives

Here we report a facile and potentially scalable method to fabricate biodegradable, breathable, and biocidal cellulose nonwovens (BCNWs) to address both environmental and hygienic problems of commercially available face masks.

Methods

TEMPO-oxidized cellulose nonwovens are rendered antiviral/antibacterial via covalent bonding with disinfecting polyhexamethylene guanidine or neomycin sulfate through carbodiimide coupling chemistry.

Results

The obtained results showed that the BCNWs have virucidal rate of >99.14%, bactericidal efficiency of >99.51%, no leaching-out effect, and excellent air permeability of >1111.5 mm s⁻¹. More importantly, the as-prepared BCNWs can inactivate SARS-CoV-2 instantly.

Conclusions

This strategy provides a new platform for the green fabrication of multifunctional cellulose nonwovens as scalable bio-protective layers with superior performance for various PPE in fighting COVID-19 or future pandemics. Additionally, replacing the non-biodegradable non-antimicrobial PP-based masks with the cellulose-based masks can reduce the plastic wastes and lower the greenhouse gas production from the incineration of disposed masks.

N95 respirator and surgical mask effectiveness against respiratory viral illnesses in the healthcare setting: A systematic review and meta-analysis

OBJECTIVE

To examine the results, level of evidence, and methodologic quality of original studies regarding surgical mask effectiveness in minimizing viral respiratory illness transmission, and, in particular, the performance of the N95 respirator versus surgical mask.

METHODS

Meta-analysis was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines with use of PubMed, MEDLINE, and the Cochrane Library databases.

RESULTS

Eight studies (9164 participants) were included after screening 153 articles. Analyses showed statistically significant differences between N95 respirator versus surgical mask use to prevent influenza-like-illness (risk ratio [RR] = 0.81, 95% confidence interval [CI] = 0.68-0.94, P < 0.05), non-influenza respiratory viral infection (RR = 0.62, 95% CI = 0.52-0.74, P < 0.05), respiratory viral infection (RR = 0.73, 95% CI = 0.65-0.82, P < 0.05), severe acute respiratory syndrome coronavirus (SARS-CoV) 1 and 2 virus infection (RR = 0.17, 95% CI = 0.06-0.49, P < 0.05), and laboratory-confirmed respiratory viral infection (RR = 0.75, 95% CI = 0.66-0.84, P < 0.05). Analyses did not indicate statistically significant results against laboratory-confirmed influenza (RR = 0.87, CI = 0.74-1.03, P > 0.05).

CONCLUSIONS

N95 respirator use was associated with fewer viral infectious episodes for healthcare workers compared with surgical masks. The N95 respirator was most effective in reducing the risk of a viral infection in the hospital setting from the SARS-CoV 1 and 2 viruses compared to the other viruses included in this investigation. Methodologic quality, risk of biases, and small number of original studies indicate the necessity for further research to be performed, especially in front-line healthcare delivery settings.

Electrospun Nanofiber-Based Viroblock/ZnO/PAN Hybrid Antiviral Nanocomposite for Personal Protective Applications

Designing novel antiviral personal protective equipment (PPE) is crucial for preventing viral infections such as COVID-19 in humans. Here, we fabricate an electrospun nanofiber-based Viroblock (VB)-loaded polyacrylonitrile (PAN)/zinc oxide (ZnO) hybrid nanocomposite for PPE applications. Five different concentrations of Viroblock (0.5%, 1.5%, 2.5%, 3.5%, and 5%) were added to PAN/ZnO solution and loaded for electrospinning. The developed samples reflected antibacterial activity of 92.59% and 88.64% against Staphylococcus aureus and Pseudomonas aeruginosa bacteria, respectively, with 5% VB loading. Moreover, a significant reduction in virus titer (37%) was observed with the 5% VB/PAN/ZnO nanofiber sheet. Hence, VB-loaded PAN/ZnO nanofibers have great potential to kill enveloped viruses such as influenzas and coronaviruses and could be the ideal candidate for the development of nanofiber-based PPE, such as facemasks and surgical gowns, which can play a key role in the protection of frontline health workers and the general public in the COVID-19 pandemic.

Is a Mask That Covers the Mouth and Nose Free from Undesirable Side Effects in Everyday Use and Free of Potential Hazards?

Many countries introduced the requirement to wear masks in public spaces for containing SARS-CoV-2 making it commonplace in 2020. Up until now, there has been no comprehensive investigation as to the adverse health effects masks can cause. The aim was to find, test, evaluate and compile scientifically proven related side effects of wearing masks. For a quantitative evaluation, 44 mostly experimental studies were referenced, and for a substantive evaluation, 65 publications were found. The literature revealed relevant adverse effects of masks in numerous disciplines. In this paper, we refer to the psychological and physical deterioration as well as multiple symptoms described because of their consistent, recurrent and uniform presentation from different disciplines as a Mask-Induced Exhaustion Syndrome (MIES). We objectified evaluation evidenced changes in respiratory physiology of mask wearers with significant correlation of O2 drop and fatigue (p < 0.05), a clustered co-occurrence of respiratory impairment and O2 drop (67%), N95 mask and CO2 rise (82%), N95 mask and O2 drop (72%), N95 mask and headache (60%), respiratory impairment and temperature rise (88%), but also temperature rise and moisture (100%) under the masks. Extended mask-wearing by the general population could lead to relevant effects and consequences in many medical fields.

Personal protective equipment for reducing the risk of COVID-19 infection among health care workers involved in emergency trauma surgery during the pandemic: An umbrella review

BACKGROUND

Health care facilities in low- and middle-income countries are inadequately resourced to adhere to current COVID-19 prevention recommendations. Recommendations for surgical emergency trauma care measures need to be adequately informed by available evidence and adapt to particular settings. To inform future recommendations, we set to summarize the effects of different personal protective equipment (PPE) on the risk of COVID-19 infection in health personnel caring for trauma surgery patients.

METHODS

We conducted an umbrella review using Living Overview of Evidence platform for COVID-19, which performs regular automated searches in MEDLINE, Embase, Cochrane Central Register of Controlled Trials, and more than 30 other sources. Systematic reviews of experimental and observational studies assessing the efficacy of PPE were included. Indirect evidence from other health care settings was also considered. Risk of bias was assessed with the AMSTAR II tool (Assessing the Methodological Quality of Systematic Reviews, Ottawa, ON, Canada), and the Grading of Recommendations, Assessment, Development, and Evaluation approach for grading the certainty of the evidence is reported (registered in International Prospective Register of Systematic Reviews, CRD42020198267).

RESULTS

Eighteen studies that fulfilled the selection criteria were included. There is high certainty that the use of N95 respirators and surgical masks is associated with a reduced risk of COVID-19 when compared with no mask use. In moderate- to high-risk environments, N95 respirators are associated with a further reduction in risk of COVID-19 infection compared with surgical masks. Eye protection also reduces the risk of contagion in this setting. Decontamination of masks and respirators with ultraviolet germicidal irradiation, vaporous hydrogen peroxide, or dry heat is effective and does not affect PPE performance or fit.

CONCLUSION

The use of PPE drastically reduces the risk of COVID-19 compared with no mask use in health care workers. N95 and equivalent respirators provide more protection than surgical masks. Decontamination and reuse appear feasible to overcome PPE shortages and enhance the allocation of limited resources. These effects are applicable to emergency trauma care and should inform future recommendations.

LEVEL OF EVIDENCE

Review, level II.

Acoustic voice characteristics with and without wearing a facemask

Facemasks are essential for healthcare workers but characteristics of the voice whilst wearing this personal protective equipment are not well understood. In the present study, we compared acoustic voice measures in recordings of sixteen adults producing standardised vocal tasks with and without wearing either a surgical mask or a KN95 mask. Data were analysed for mean spectral levels at 0-1 kHz and 1-8 kHz regions, an energy ratio between 0-1 and 1-8 kHz (LH1000), harmonics-to-noise ratio (HNR), smoothed cepstral peak prominence (CPPS), and vocal intensity. In connected speech there was significant attenuation of mean spectral level at 1-8 kHz region and there was no significant change in this measure at 0-1 kHz. Mean spectral levels of vowel did not change significantly in mask-wearing conditions. LH1000 for connected speech significantly increased whilst wearing either a surgical mask or KN95 mask but no significant change in this measure was found for vowel. HNR was higher in the mask-wearing conditions than the no-mask condition. CPPS and vocal intensity did not change in mask-wearing conditions. These findings implied an attenuation effects of wearing these types of masks on the voice spectra with surgical mask showing less impact than the KN95.

Visible-Light-Driven and Self-Hydrogen-Donated Nanofibers Enable Rapid-Deployable Antimicrobial Bioprotection

The novel coronavirus SARS-CoV-2 has prompted a worldwide pandemic and poses a great threat to public safety and global economies. Most present personal protective equipment (PPE) used to intercept pathogenic microorganisms is deficient in biocidal properties. Herein, we present green nanofibers with effective antibacterial and antiviral activities that can provide sustainable bioprotection by continuously producing reactive oxygen species (ROS). The superiority of the design is that the nanofibers can absorb and store visible light energy and maintain the activity under light or dark environment. Moreover, the nanofibers can uninterruptedly release ROS in the absence of an external hydrogen donor, acting as a biocide under all weather conditions. A facile spraying method is proposed to rapidly deploy the functional nanofibers to existing PPE, such as protective suits and masks. The modified PPE exhibit stable ROS production, excellent capacity for storing activity potential, long-term durability, and high bactericidal (>99.9%) and viricidal (>99.999%) efficacies.

Facemask use in community settings to prevent respiratory infection transmission: A rapid review and meta-analysis

INTRODUCTION

Synthesis of the available evidence on the effectiveness of medical and cloth facemask use by the general public in community settings is required to learn lessons for future respiratory epidemics/pandemics.

METHOD

Search terms relating to facemasks, infection and community settings were used for PubMed, the Cochrane Library Database and Google Scholar. A meta-analysis was conducted using a random-effects model.

RESULTS

The review included 12 primary studies on the effectiveness of medical facemask use to prevent influenza, influenza-like illness, SARS-CoV, and SARS-CoV-2 transmission. The meta-analysis demonstrated that facemask use significantly reduces the risk of transmitting these respiratory infections (pooled OR = 0.66, 95% CI 0.54-0.81). Of the 12 studies, 10 clinical trials suggested that respiratory infection incidence is lower with high medical facemask compliance, early use and use in combination with intensive hand hygiene. One cohort study conducted during the SARS-CoV-2 pandemic demonstrated that facemasks are effective in reducing SARS-CoV-2 transmission when used before those who are infected develop symptoms. One case-control study reported that controls used medical facemasks more often than cases infected with SARS-CoV (p <  0.05). No primary study on cloth facemask effectiveness to prevent respiratory infection transmission was found.

CONCLUSION

Based on the available evidence, medical facemask use by healthy and sick individuals is recommended for preventing respiratory infection transmission in community settings. Medical facemask effectiveness is dependent on compliance and utilization in combination with preventive measures such as intensive hand hygiene. No direct evidence is currently available in humans supporting the recommendation of cloth facemask use to prevent respiratory infection transmission.

Individual and population level protection from particulate matter exposure by wearing facemasks

Because of the severe air pollution in northern China, facemasks have gained popularity in this area in recent years. Although the results of previous studies have shown the effectiveness of wearing facemasks for intercepting particles, the individual differences and the overall health benefits of wearing facemasks have not been comprehensively documented. In this study, using both model and personal tests under various conditions, we test eight major brands of facemasks for their removal efficiencies (REs) of particulate matter (PM) in six size ranges (from 0.3 μm to >10 μm). The results are used to assess the overall exposure reduction at the individual and population levels in Beijing. We find significant differences in REs among PM sizes, facemask brands, pollution levels, and genders. Combining the information on the usage of various brands, facemask wearing rates, and PM_2.5 concentrations in the ambient and indoor air in this area, we evaluate the overall effect of facemask wearing on PM_2.5 exposure reduction. It is quantitatively demonstrated that because people spend most time indoors, facemask protection is limited. For facemask wearers, the overall exposure can be reduced by less than 20%, whereas the reduction rate is as low as 2.4 ± 1.6% for the entire adult populations even in the year with the highest level of pollution with an annual mean PM_2.5 concentration of 102 ± 98 μg∙m^-3. As a strategy of self-protection from long-term exposure to particulate matter, wearing facemasks outdoors is inferior to the installation of indoor air purifiers.

Physical interventions to interrupt or reduce the spread of respiratory viruses

BACKGROUND

Viral epidemics or pandemics of acute respiratory infections (ARIs) pose a global threat. Examples are influenza (H1N1) caused by the H1N1pdm09 virus in 2009, severe acute respiratory syndrome (SARS) in 2003, and coronavirus disease 2019 (COVID-19) caused by SARS-CoV-2 in 2019. Antiviral drugs and vaccines may be insufficient to prevent their spread. This is an update of a Cochrane Review published in 2007, 2009, 2010, and 2011. The evidence summarised in this review does not include results from studies from the current COVID-19 pandemic.

OBJECTIVES

To assess the effectiveness of physical interventions to interrupt or reduce the spread of acute respiratory viruses.

SEARCH METHODS

We searched CENTRAL, PubMed, Embase, CINAHL on 1 April 2020. We searched ClinicalTrials.gov, and the WHO ICTRP on 16 March 2020. We conducted a backwards and forwards citation analysis on the newly included studies.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and cluster-RCTs of trials investigating physical interventions (screening at entry ports, isolation, quarantine, physical distancing, personal protection, hand hygiene, face masks, and gargling) to prevent respiratory virus transmission. In previous versions of this review we also included observational studies. However, for this update, there were sufficient RCTs to address our study aims.   DATA COLLECTION AND ANALYSIS: We used standard methodological procedures expected by Cochrane. We used GRADE to assess the certainty of the evidence. Three pairs of review authors independently extracted data using a standard template applied in previous versions of this review, but which was revised to reflect our focus on RCTs and cluster-RCTs for this update. We did not contact trialists for missing data due to the urgency in completing the review. We extracted data on adverse events (harms) associated with the interventions.

MAIN RESULTS

We included 44 new RCTs and cluster-RCTs in this update, bringing the total number of randomised trials to 67. There were no included studies conducted during the COVID-19 pandemic. Six ongoing studies were identified, of which three evaluating masks are being conducted concurrent with the COVID pandemic, and one is completed. Many studies were conducted during non-epidemic influenza periods, but several studies were conducted during the global H1N1 influenza pandemic in 2009, and others in epidemic influenza seasons up to 2016. Thus, studies were conducted in the context of lower respiratory viral circulation and transmission compared to COVID-19. The included studies were conducted in heterogeneous settings, ranging from suburban schools to hospital wards in high-income countries; crowded inner city settings in low-income countries; and an immigrant neighbourhood in a high-income country. Compliance with interventions was low in many studies. The risk of bias for the RCTs and cluster-RCTs was mostly high or unclear. Medical/surgical masks compared to no masks We included nine trials (of which eight were cluster-RCTs) comparing medical/surgical masks versus no masks to prevent the spread of viral respiratory illness (two trials with healthcare workers and seven in the community). There is low certainty evidence from nine trials (3507 participants) that wearing a mask may make little or no difference to the outcome of influenza-like illness (ILI) compared to not wearing a mask (risk ratio (RR) 0.99, 95% confidence interval (CI) 0.82 to 1.18. There is moderate certainty evidence that wearing a mask probably makes little or no difference to the outcome of laboratory-confirmed influenza compared to not wearing a mask (RR 0.91, 95% CI 0.66 to 1.26; 6 trials; 3005 participants). Harms were rarely measured and poorly reported. Two studies during COVID-19 plan to recruit a total of 72,000 people. One evaluates medical/surgical masks (N = 6000) (published Annals of Internal Medicine, 18 Nov 2020), and one evaluates cloth masks (N = 66,000). N95/P2 respirators compared to medical/surgical masks We pooled trials comparing N95/P2 respirators with medical/surgical masks (four in healthcare settings and one in a household setting). There is uncertainty over the effects of N95/P2 respirators when compared with medical/surgical masks on the outcomes of clinical respiratory illness (RR 0.70, 95% CI 0.45 to 1.10; very low-certainty evidence; 3 trials; 7779 participants) and ILI (RR 0.82, 95% CI 0.66 to 1.03; low-certainty evidence; 5 trials; 8407 participants). The evidence is limited by imprecision and heterogeneity for these subjective outcomes. The use of a N95/P2 respirator compared to a medical/surgical mask probably makes little or no difference for the objective and more precise outcome of laboratory-confirmed influenza infection (RR 1.10, 95% CI 0.90 to 1.34; moderate-certainty evidence; 5 trials; 8407 participants). Restricting the pooling to healthcare workers made no difference to the overall findings. Harms were poorly measured and reported, but discomfort wearing medical/surgical masks or N95/P2 respirators was mentioned in several studies. One ongoing study recruiting 576 people compares N95/P2 respirators with medical surgical masks for healthcare workers during COVID-19. Hand hygiene compared to control Settings included schools, childcare centres, homes, and offices. In a comparison of hand hygiene interventions with control (no intervention), there was a 16% relative reduction in the number of people with ARIs in the hand hygiene group (RR 0.84, 95% CI 0.82 to 0.86; 7 trials; 44,129 participants; moderate-certainty evidence), suggesting a probable benefit. When considering the more strictly defined outcomes of ILI and laboratory-confirmed influenza, the estimates of effect for ILI (RR 0.98, 95% CI 0.85 to 1.13; 10 trials; 32,641 participants; low-certainty evidence) and laboratory-confirmed influenza (RR 0.91, 95% CI 0.63 to 1.30; 8 trials; 8332 participants; low-certainty evidence) suggest the intervention made little or no difference. We pooled all 16 trials (61,372 participants) for the composite outcome of ARI or ILI or influenza, with each study only contributing once and the most comprehensive outcome reported. The pooled data showed that hand hygiene may offer a benefit with an 11% relative reduction of respiratory illness (RR 0.89, 95% CI 0.84 to 0.95; low-certainty evidence), but with high heterogeneity. Few trials measured and reported harms. There are two ongoing studies of handwashing interventions in 395 children outside of COVID-19. We identified one RCT on quarantine/physical distancing. Company employees in Japan were asked to stay at home if household members had ILI symptoms. Overall fewer people in the intervention group contracted influenza compared with workers in the control group (2.75% versus 3.18%; hazard ratio 0.80, 95% CI 0.66 to 0.97). However, those who stayed at home with their infected family members were 2.17 times more likely to be infected. We found no RCTs on eye protection, gowns and gloves, or screening at entry ports.

AUTHORS' CONCLUSIONS

The high risk of bias in the trials, variation in outcome measurement, and relatively low compliance with the interventions during the studies hamper drawing firm conclusions and generalising the findings to the current COVID-19 pandemic. There is uncertainty about the effects of face masks. The low-moderate certainty of the evidence means our confidence in the effect estimate is limited, and that the true effect may be different from the observed estimate of the effect. The pooled results of randomised trials did not show a clear reduction in respiratory viral infection with the use of medical/surgical masks during seasonal influenza. There were no clear differences between the use of medical/surgical masks compared with N95/P2 respirators in healthcare workers when used in routine care to reduce respiratory viral infection. Hand hygiene is likely to modestly reduce the burden of respiratory illness. Harms associated with physical interventions were under-investigated. There is a need for large, well-designed RCTs addressing the effectiveness of many of these interventions in multiple settings and populations, especially in those most at risk of ARIs.

Daylight-Induced Antibacterial and Antiviral Cotton Cloth for Offensive Personal Protection

Cotton fabrics with durable and reusable daylight-induced antibacterial/antiviral functions were developed by using a novel fabrication process, which employs strong electrostatic interaction between cationic cotton fibers and anionic photosensitizers. The cationic cotton contains polycationic short chains produced by a self-propagation of 2-diehtylaminoehtyl chloride (DEAE-Cl) on the surface of cotton fibers. Then, the fabric (i.e., polyDEAE@cotton) can be readily functionalized with anionic photosensitizers like rose Bengal and sodium 2-anthraquinone sulfate to produce biocidal reactive oxygen species (ROS) under light exposure and consequently provide the photo-induced biocidal functions. The biocidal properties of the photo-induced fabrics (PIFs) were demonstrated by ROS production measurements, bactericidal performance against bacteria (e.g., E coli and L. innocua), and antiviral results against T7 bacteriophage. The PIFs achieved 99.9999% (6 log) reductions against bacteria and the bacteriophage within 60 min of daylight exposure. Moreover, the PIFs showcase excellent washability and photostability, making them ideal materials for reusable face masks and protective suits with improved biological protections compared with traditional PPE. This work demonstrated that the cationized cotton could serve as a platform for different functionalization applications, and the resulting fiber materials could inspire the development of reusable and sustainable PPE with significant bioprotective properties to fight the COVID-19 pandemic as well as the spread of other contagious diseases.

The effectiveness and efficacy of respiratory protective equipment (RPE) in dentistry and other health care settings: a systematic review

OBJECTIVE

The global pandemic of coronavirus disease-19, caused by the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), is the latest hazard facing healthcare workers (HCW) including dental care workers (DCW). It is clear that the major mode of SARS-CoV-2 transmission is the airborne route, through inhalation of virus-infested aerosols and droplets. Several respiratory protection equipment (RPE), including masks, face shields/visors, and respirators, are available to obviate facial and conjunctival contamination by microbes. However, as their barrier value against microbial inhalation has not been evaluated, we systematically reviewed the data on the effectiveness and efficacy of facemasks and respirators, including protective eyewear, with particular emphasis on dental healthcare.

MATERIAL AND METHODS

PubMed, MEDLINE, the Cochrane Library, and Embase databases were searched between 01January 1990 and 15 May 2020.

RESULTS

Of 310 identified English language records, 21 were included as per eligibility criteria. In clinical terms, wearing layered, face-fitting masks/respirators and protective-eyewear can limit the spread of infection among HCWs. Specifically, combined interventions such as a face mask and a face shield, better resist bioaerosol inhalation than either alone. The prolonged and over-extended use of surgical masks compromise their effectiveness.

CONCLUSIONS

In general, RPE is effective as a barrier protection against aerosolized microbes in healthcare settings. But their filtration efficacy is compromised by the (i) inhalant particle size, (ii) airflow dynamics, (iii) mask-fit factor, (iv) period of wear, (v) 'wetness' of the masks, and (vi) their fabrication quality. The macro-data presented here should inform policy formulation on RPE wear amongst HCWs.

Efficacy of masks and face coverings in controlling outward aerosol particle emission from expiratory activities

The COVID-19 pandemic triggered a surge in demand for facemasks to protect against disease transmission. In response to shortages, many public health authorities have recommended homemade masks as acceptable alternatives to surgical masks and N95 respirators. Although mask wearing is intended, in part, to protect others from exhaled, virus-containing particles, few studies have examined particle emission by mask-wearers into the surrounding air. Here, we measured outward emissions of micron-scale aerosol particles by healthy humans performing various expiratory activities while wearing different types of medical-grade or homemade masks. Both surgical masks and unvented KN95 respirators, even without fit-testing, reduce the outward particle emission rates by 90% and 74% on average during speaking and coughing, respectively, compared to wearing no mask, corroborating their effectiveness at reducing outward emission. These masks similarly decreased the outward particle emission of a coughing superemitter, who for unclear reasons emitted up to two orders of magnitude more expiratory particles via coughing than average. In contrast, shedding of non-expiratory micron-scale particulates from friable cellulosic fibers in homemade cotton-fabric masks confounded explicit determination of their efficacy at reducing expiratory particle emission. Audio analysis of the speech and coughing intensity confirmed that people speak more loudly, but do not cough more loudly, when wearing a mask. Further work is needed to establish the efficacy of cloth masks at blocking expiratory particles for speech and coughing at varied intensity and to assess whether virus-contaminated fabrics can generate aerosolized fomites, but the results strongly corroborate the efficacy of medical-grade masks and highlight the importance of regular washing of homemade masks.

Efficacy of masks and face coverings in controlling outward aerosol particle emission from expiratory activities

The COVID-19 pandemic triggered a surge in demand for facemasks to protect against disease transmission. In response to shortages, many public health authorities have recommended homemade masks as acceptable alternatives to surgical masks and N95 respirators. Although mask wearing is intended, in part, to protect others from exhaled, virus-containing particles, few studies have examined particle emission by mask-wearers into the surrounding air. Here, we measured outward emissions of micron-scale aerosol particles by healthy humans performing various expiratory activities while wearing different types of medical-grade or homemade masks. Both surgical masks and unvented KN95 respirators, even without fit-testing, reduce the outward particle emission rates by 90% and 74% on average during speaking and coughing, respectively, compared to wearing no mask, corroborating their effectiveness at reducing outward emission. These masks similarly decreased the outward particle emission of a coughing superemitter, who for unclear reasons emitted up to two orders of magnitude more expiratory particles via coughing than average. In contrast, shedding of non-expiratory micron-scale particulates from friable cellulosic fibers in homemade cotton-fabric masks confounded explicit determination of their efficacy at reducing expiratory particle emission. Audio analysis of the speech and coughing intensity confirmed that people speak more loudly, but do not cough more loudly, when wearing a mask. Further work is needed to establish the efficacy of cloth masks at blocking expiratory particles for speech and coughing at varied intensity and to assess whether virus-contaminated fabrics can generate aerosolized fomites, but the results strongly corroborate the efficacy of medical-grade masks and highlight the importance of regular washing of homemade masks.

Reusable Face Masks as Alternative for Disposable Medical Masks: Factors that Affect their Wear-Comfort

The coronavirus outbreak that commenced at the end of 2019 has led to a dramatic increase in the demand for face masks. In countries that are experiencing a shortage of face masks as a result of panic buying or inadequate supply, reusable fabric masks have become a popular option, because they are often considered more cost-effective and environmentally friendly than disposable medical masks. Nevertheless, there remains a significant variation in the quality and performance of existing face masks; not all are simultaneously able to provide protection against the extremely contagious virus and be comfortable to wear. This study aims to examine the influential factors that affect the comfort of reusable face masks, but not to assess the antimicrobial or antiviral potential. Seven types of masks were selected in this study and subjected to air and water vapor permeability testing, thermal conductivity testing and a wear trial. The results indicate that washable face masks made of thin layers of knitted fabric with low density and a permeable filter are more breathable. Additionally, masks that contain sufficient highly thermally conductive materials and have good water vapor permeability are often more comfortable to wear as they can transfer heat and moisture from the body quickly, and thus do not easily dampen and deteriorate.

Personal protective equipment and evidence-based advice for surgical departments during COVID-19

BACKGROUND

Inconsistencies regarding the use of appropriate personal protective equipment (PPE) have raised concerns for the safety of surgical staff during the coronavirus disease 2019 (COVID-19) pandemic. This rapid review synthesizes the literature and includes input from clinical experts to provide evidence-based guidance for surgical services.

METHODS

The rapid review comprised of targeted searches in PubMed and grey literature. Pertinent findings were discussed by a working group of clinical experts, and consensus recommendations, consistent with Australian and New Zealand Government guidelines, were formulated.

RESULTS

There was a paucity of high-quality primary studies specifically investigating appropriate surgical PPE for healthcare workers treating patients possibly infected with COVID-19. SARS-CoV-2 is capable of aerosol, droplet and fomite transmission, making it essential to augment standard infection control measures with appropriate PPE, especially during surgical emergencies and aerosol-generating procedures. All biological material should be treated a potential source of SARS-COV-2. Staff must have formal training in the use of PPE and should be supervised by a colleague during donning and doffing. Patients with suspected or confirmed COVID-19 should wear a surgical mask during transfer to and from theatre. Potential solutions exist in the literature to extend the use of surgical P2/N95 respirators in situations of limited supply.

CONCLUSION

PPE is advised for all high-risk procedures and when a patient's COVID-19 status is unknown. Surgical departments should facilitate staggered rostering, remote meeting attendance, and self-isolation of symptomatic staff. Vulnerable surgical staff should be identified and excluded from operations with a high risk of COVID-19 infection.

Advances in Antiviral Material Development

The rise in human pandemics demands prudent approaches in antiviral material development for disease prevention and treatment via effective protective equipment and therapeutic strategy. However, the current state of the antiviral materials research is predominantly aligned towards drug development and its related areas, catering to the field of pharmaceutical technology. This review distinguishes the research advances in terms of innovative materials exhibiting antiviral activities that take advantage of fast-developing nanotechnology and biopolymer technology. Essential concepts of antiviral principles and underlying mechanisms are illustrated, followed with detailed descriptions of novel antiviral materials including inorganic nanomaterials, organic nanomaterials and biopolymers. The biomedical applications of the antiviral materials are also elaborated based on the specific categorization. Challenges and future prospects are discussed to facilitate the research and development of protective solutions and curative treatments.

Surface distribution of severe acute respiratory syndrome coronavirus 2 in Leishenshan Hospital in China

The global pandemic of Corona Virus Disease 2019 (COVID-19) necessitated the rapid construction of field hospitals as the main strategies to control the detrimental effects of the outbreak. Little is known about the extent of the environmental contamination of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in an urgently field hospital. A total of 66 surface samples were randomly collected from a general isolation ward and an ICU (intensive care unit) at a rapidly built field hospital (Wuhan Leishenshan Hospital) in Wuhan, China, from 12 March to 17 March 2020. The samples were used for SARS-CoV-2 detection and ATP (adenosine triphosphate) monitoring. Among these samples, 3.03% tested positive for SARS-CoV-2. The nurses' hands and nurse station in the ICU were weakly positive (CT value = 38.79; CT value = 37.56) and the ATP value of these two sites was higher than the mean value of all samples (ATP = 817; ATP = 577). The environmental cleaning and disinfection normalization bundle measures in Leishenshan hospital included air disinfection, object surface cleaning and disinfection, instrument equipment surface disinfection and hand hygiene, etc. These have been tested and were shown to be reliable and useful. Our experience can provide a useful reference in the fight against the ongoing pandemic of COVID-19.

Comparison of Face-Touching Behaviors Before and During the Coronavirus Disease 2019 Pandemic

IMPORTANCE

There is insufficient evidence on the efficacy of masks in the general population for the prevention of coronavirus disease 2019 (COVID-19) in public areas. Therefore, it is imperative to investigate the association of mandatory mask-wearing policies with behaviors associated with the transmission of COVID-19.

OBJECTIVE

To assess the association of mask wearing with face-touching behavior among the general population in public areas.

DESIGN, SETTING, AND PARTICIPANTS

This cross-sectional study used videos recorded in public transportation stations, streets, and parks among the general population in China, Japan, South Korea, Western Europe (ie, England, France, Germany, Spain, and Italy), and the US to analyze mask-wearing and face-touching behavior in public areas. Videos before the COVID-19 pandemic were defined as those recorded from January 2018 to October 2019, and those during the COVID-19 pandemic were defined as those recorded during February 2020 to March 2020 in China, Japan, and South Korea and during March 2020 in Western Europe and the US. Individuals who clearly displayed their face and face-touching behavior were included, and those whose behaviors were influenced by filming or public events were excluded.

EXPOSURES

Mandatory mask-wearing policies enacted at various time points in China, Japan, South Korea, Western Europe, and the US.

MAIN OUTCOMES AND MEASURES

Proportion of individuals wearing masks and incidence of face touching.

RESULTS

This study included 4699 individuals before the COVID-19 pandemic and 2887 individuals during the pandemic. During the periods studied, mask wearing increased in all regions except the US, from 20 of 1745 individuals (1.1%) to 1090 of 1097 individuals (99.4%) in mainland China (P < .001), 44 of 1422 individuals (3.1%) to 346 of 893 individuals (38.7%) in Japan (P < .001), 6 of 717 individuals (0.8%) to 277 of 324 individuals (85.5% ) in South Korea (P < .001), 1 of 546 individuals (0.2%) to 6 of 379 individuals (1.6%) in Western Europe (P = .02), and 1 of 269 individuals (0.4%) to 4 of 194 individuals (2.1%) in the US (P = .17). Surgical masks were predominant in China (989 masks [89.1%]), and fabric masks were predominant in the other regions (Japan: 371 masks [95.1%]; South Korea: 240 masks [84.8%]; Western Europe: 6 masks [85.7%]; US: 5 masks [100%]). Face-touching behaviors decreased from before COVID-19 to during COVID-19 among individuals in China (72 incidences of 1745 observations [4.1%] to 12 incidences of 1097 observations [1.1%]; P < .001), South Korea (80 incidences of 717 observations [11.2%] to 7 incidences of 324 observations [2.2%]; P < .001), and Europe (62 incidences of 546 observations [11.4%] to 23 incidences of 379 observations [6.1%]; P = .01). Logistic regression found that mask wearing was associated with a reduction in face touching in China (odds ratio [OR], 3.91; 95% CI, 2.11-7.24) and South Korea (OR, 6.69; 95% CI, 2.69-16.69) and of touching the nose, mouth, and eyes (China: OR, 8.60; 95% CI, 2.65-27.86; South Korea: OR, 29.27; 95% CI, 1.79-478.22).

CONCLUSIONS AND RELEVANCE

The findings of this cross-sectional study suggest that mandatory mask-wearing policies were associated with increased mask wearing during the COVID-19 pandemic. Mask wearing was associated with reduced face-touching behavior, especially touching of the eyes, nose, and mouth, which may prevent contact transmission of COVID-19 among the general population in public areas.

Online National Health Agency Mask Guidance for the Public in Light of COVID-19: Content Analysis

Background

The rapid global spread of the coronavirus disease (COVID-19) has compelled national governments to issue guidance on the use of face masks for members of the general public. To date, no work has assessed how this guidance differs across governments.

Objective

This study seeks to contribute to a rational and consistent global response to infectious disease by determining how guidelines differ across nations and regions.

Methods

A content analysis of health agency mask guidelines on agency websites was performed in late March 2020 among 25 countries and regions with large numbers of COVID-19 cases. Countries and regions were assigned across the coding team by language proficiency, with Google Translate used as needed. When available, both the original and English language version of guidance were reviewed.

Results

All examined countries and regions had some form of guidance online, although detail and clarity differed. Although 9 countries and regions recommended surgical, medical, or unspecified masks in public and poorly ventilated places, 16 recommended against people wearing masks in public. There were 2 countries that explicitly recommended against fabric masks. In addition, 12 failed to outline the minimum basic World Health Organization guidance for masks.

Conclusions

Online guidelines for face mask use to prevent COVID-19 in the general public are currently inconsistent across nations and regions, and have been changing often. Efforts to create greater standardization and clarity should be explored in light of the status of COVID-19 as a global pandemic.

A rapid systematic review of the efficacy of face masks and respirators against coronaviruses and other respiratory transmissible viruses for the community, healthcare workers and sick patients

Background

The pandemic of COVID-19 is growing, and a shortage of masks and respirators has been reported globally. Policies of health organizations for healthcare workers are inconsistent, with a change in policy in the US for universal face mask use. The aim of this study was to review the evidence around the efficacy of masks and respirators for healthcare workers, sick patients and the general public.

Methods

A systematic review of randomized controlled clinical trials on use of respiratory protection by healthcare workers, sick patients and community members was conducted. Articles were searched on Medline and Embase using key search terms.

Results

A total of 19 randomised controlled trials were included in this study – 8 in community settings, 6 in healthcare settings and 5 as source control. Most of these randomised controlled trials used different interventions and outcome measures. In the community, masks appeared to be effective with and without hand hygiene, and both together are more protective. Randomised controlled trials in health care workers showed that respirators, if worn continually during a shift, were effective but not if worn intermittently. Medical masks were not effective, and cloth masks even less effective. When used by sick patients randomised controlled trials suggested protection of well contacts.

Conclusion

The study suggests that community mask use by well people could be beneficial, particularly for COVID-19, where transmission may be pre-symptomatic. The studies of masks as source control also suggest a benefit, and may be important during the COVID-19 pandemic in universal community face mask use as well as in health care settings. Trials in healthcare workers support the use of respirators continuously during a shift. This may prevent health worker infections and deaths from COVID-19, as aerosolisation in the hospital setting has been documented.

Impact of structural features on dynamic breathing resistance of healthcare face mask

In order to provide an overall evaluation and characterization of the comfort sensation and performance of face mask related to breathing resistance for healthcare in fog and haze weather, and address the influence of structural features on breathing resistance properties, an experimental set-up was developed, which was able to continuously change the direction and rate of air flow and the breathing frequency to simulate the dynamic breathing process during the actual wearing of face mask. The dynamic changes of airflow rate and the breathing resistance were acquired by a virtual instrument (VI) system and a microelectronics system. Six evaluation indices were defined for the dynamic performance and comfort sensation of face mask, derived from the source data of dynamic breathing resistance. Twelve types of face masks from different department stores with different features such as shape, respiratory valve, brand, main materials and protection level were tested using the experimental set-up. The one-way ANOVA analysis was carried out to identify the significance of the differences of the indices among the test masks. The results showed that each evaluation index was significantly different (P < 0.05) among different test masks. The change rate of breathing resistance could be obtained using the dynamic measurement of breathing resistance and could be applied for the dynamic performance evaluation of face mask compared with the static measurement of breathing resistance under constant airflow rate. The influences of structural features such as respiratory valve, shape and main materials on breathing resistance were evaluated and analyzed. The face masks with respiratory valve had lower change rate of breathing resistance. Moreover, the cup type mask had lower change rate of breathing resistance than the folding mask. Furthermore, the cotton mask had lower change rate of breathing resistance than the nonwoven fabric mask.

Comparing mask fit and usability of traditional and nanofibre N95 filtering facepiece respirators before and after nursing procedures

BACKGROUND

The reliability of N95 filtering facepiece respirators (FFRs) depends on correct fitting. The perceived usability of FFRs is equally important because discomfort during usage may affect compliance. Body movements during nursing procedures may also increase the risk of face seal leakage.

AIM

To evaluate the mask fit and usability of the best-fitting 3M N95 FFR and the nanofibre N95 FFR before and after nursing procedures. The physical properties of these FFRs were also examined.

METHODS

This experimental study had a one-group multiple comparison design. In total, 104 nursing students participated, and performed nursing procedures for 10 min when wearing the best-fitting 3M FFR and the nanofibre FFR. Mask fit and perceived usability of the FFRs were evaluated.

FINDINGS

More participants failed to obtain a fit factor ≥100 when using the best-fitting 3M FFR than when wearing the nanofibre FFR (33.7% vs 21.2%) after the procedures (P=0.417). The nanofibre FFR also demonstrated higher usability than the 3M FFRs in terms of facial heat, breathability, facial pressure, speech intelligibility, itchiness, difficulty of maintaining the mask in place, and comfort level (P<0.001). The nanofibre FFR was also lighter, thinner and had slightly higher bacterial filtration efficiency than the 3M FFRs.

CONCLUSION

The nanofibre FFR demonstrated significantly better usability than the 3M FFRs. None of the respirators were able to provide consistent protection for the wearer, as detected by face seal leakage after performing nursing procedures. Further improvement in the prototype design is needed to increase compliance and ensure the respiratory protection of users.

Editorial: the airborne microbiome - implications for aerosol transmission and infection control - special issue

Although the title of the Special Issue is 'Airborne Microbiome' the manuscripts received have highlighted a variety of peripheral, yet related aspects of this. The contributions are a mixture of primary research, reviews and commentaries, including: new methods to explore environmental niches where such microbes may grow, their detection and characterisation in the human host, which pathogens are present in the respiratory tract and can be exhaled in human breath to potentially spread via the airborne route, and some strategies for their control. Finally, a historical-to-current overview explores human-microbial interactions, including problems with sampling and detection methods, drug resistance, the role of super-spreaders and issues around research funding.

Rechargeable polyamide-based N-halamine nanofibrous membranes for renewable, high-efficiency, and antibacterial respirators

Emerging infectious diseases (EIDs) have been acknowledged as a major public health concern worldwide. Unfortunately, most protective respirators used to prevent EID transmission suffer from the disadvantage of lacking antimicrobial activity, leading to an increased risk of cross-contamination and post-infection. Herein, we report a novel and facile strategy to fabricate rechargeable and biocidal air filtration materials by creating advanced N-halamine structures based on electrospun polyamide (PA) nanofibers. Our approach can endow the resultant nanofibrous membranes with powerful biocidal activity (6 log CFU reduction against E. coli), an ultrahigh fine particle capture efficiency of 99.999% (N100 level for masks), and can allow the antibacterial efficacy and air filtration performance to be renewed in a one-step chlorination process, which has never been reported before. More importantly, for the first time, we revealed the synergistic effect involving the intrinsic structure of polymers and the assembling structure of nanofibers on the chlorination capacity. The successful fabrication of such a fascinating membrane can provide new insights into the development of nanofibrous materials in a multifunctional, durable, and renewable form.

Practical Guidance for Clinical Microbiology Laboratories: Viruses Causing Acute Respiratory Tract Infections

Respiratory viral infections are associated with a wide range of acute syndromes and infectious disease processes in children and adults worldwide. Many viruses are implicated in these infections, and these viruses are spread largely via respiratory means between humans but also occasionally from animals to humans. This article is an American Society for Microbiology (ASM)-sponsored Practical Guidance for Clinical Microbiology (PGCM) document identifying best practices for diagnosis and characterization of viruses that cause acute respiratory infections and replaces the most recent prior version of the ASM-sponsored Cumitech 21 document, Laboratory Diagnosis of Viral Respiratory Disease, published in 1986. The scope of the original document was quite broad, with an emphasis on clinical diagnosis of a wide variety of infectious agents and laboratory focus on antigen detection and viral culture. The new PGCM document is designed to be used by laboratorians in a wide variety of diagnostic and public health microbiology/virology laboratory settings worldwide. The article provides guidance to a rapidly changing field of diagnostics and outlines the epidemiology and clinical impact of acute respiratory viral infections, including preferred methods of specimen collection and current methods for diagnosis and characterization of viral pathogens causing acute respiratory tract infections. Compared to the case in 1986, molecular techniques are now the preferred diagnostic approaches for the detection of acute respiratory viruses, and they allow for automation, high-throughput workflows, and near-patient testing. These changes require quality assurance programs to prevent laboratory contamination as well as strong preanalytical screening approaches to utilize laboratory resources appropriately. Appropriate guidance from laboratorians to stakeholders will allow for appropriate specimen collection, as well as correct test ordering that will quickly identify highly transmissible emerging pathogens.

Characterization of Aerosols Generated During Patient Care Activities

Background

Questions remain about the degree to which aerosols are generated during routine patient care activities and whether such aerosols could transmit viable pathogens to healthcare personnel (HCP). The objective of this study was to measure aerosol production during multiple patient care activities and to examine the samples for bacterial pathogens.

Methods

Five aerosol characterization instruments were used to measure aerosols during 7 patient care activities: patient bathing, changing bed linens, pouring and flushing liquid waste, bronchoscopy, noninvasive ventilation, and nebulized medication administration (NMA). Each procedure was sampled 5 times. An SKC BioSampler was used for pathogen recovery. Bacterial cultures were performed on the sampling solution. Patients on contact precautions for drug-resistant organisms were selected for most activity sampling. Any patient undergoing bronchoscopy was eligible.

Results

Of 35 sampling episodes, only 2 procedures showed a significant increase in particle concentrations over baseline: NMA and bronchoscopy with NMA. Bronchoscopy without NMA and noninvasive ventilation did not generate significant aerosols. Of 78 cultures from the impinger samples, 6 of 28 baseline samples (21.4%) and 14 of 50 procedure samples (28.0%) were positive.

Conclusions

In this study, significant aerosol generation was only observed during NMA, both alone and during bronchoscopy. Minimal viable bacteria were recovered, mostly common environmental organisms. Although more research is needed, these data suggest that some of the procedures considered to be aerosol-generating may pose little infection risk to HCP.

Daylight-driven rechargeable antibacterial and antiviral nanofibrous membranes for bioprotective applications

Emerging infectious diseases (EIDs) are a significant burden on global economies and public health. Most present personal protective equipment used to prevent EID transmission and infections is typically devoid of antimicrobial activity. We report on green bioprotective nanofibrous membranes (RNMs) with rechargeable antibacterial and antiviral activities that can effectively produce biocidal reactive oxygen species (ROS) solely driven by the daylight. The premise of the design is that the photoactive RNMs can store the biocidal activity under light irradiation and readily release ROS under dim light or dark conditions, making the biocidal function "always online." The resulting RNMs exhibit integrated properties of fast ROS production, ease of activity storing, long-term durability, robust breathability, interception of fine particles (>99%), and high bactericidal (>99.9999%) and virucidal (>99.999%) efficacy, which enabled to serve as a scalable biocidal layer for protective equipment by providing contact killing against pathogens either in aerosol or in liquid forms. The successful synthesis of these fascinating materials may provide new insights into the development of protection materials in a sustainable, self-recharging, and structurally adaptive form.

Cellulose-based virus-retentive filters: a review

Viral filtration is a critical step in the purification of biologics and in the monitoring of microbiological water quality. Viral filters are also essential protection elements against airborne viral particles. The present review first focuses on cellulose-based filter media currently used for size-exclusion and/or adsorptive filtration of viruses from biopharmaceutical and environmental water samples. Data from spiking studies quantifying the viral filtration performance of cellulosic filters are detailed, i.e., first, the virus reduction capacity of regenerated cellulose hollow fiber filters in the manufacturing process of blood products and, second, the efficiency of virus recovery/concentration from water samples by the viradel (virus adsorption-elution) method using charge modified, electropositive cellulosic filters or conventional electronegative cellulose ester microfilters. Viral analysis of field water samples by the viradel technique is also surveyed. This review then describes cellulose-based filter media used in individual protection equipment against airborne viral pathogens, presenting innovative filtration media with virucidal properties. Some pros and cons of cellulosic viral filters and perspectives for cellulose-based materials in viral filtration are underlined in the review.

Quantification of leakage of sub-micron aerosols through surgical masks and facemasks for pediatric use

Surgical respirators, surgical masks (SMs), and facemasks for pediatric use (FPUs) are routinely used in the U.S. healthcare industry as personal protective equipment (PPE) against infectious diseases. While N95s including surgical respirators have been routinely studied, SMs and FPUs have not received as much attention, particularly in the context of aerosolized threats. This is because SMs and PFUs are not designed to protect against sub-micron aerosols. However, with the possibility of new or re-emerging airborne diseases or bio-aerosol weapons lingering, combined with the limited availability of respirators and logistical issues associated with fit-testing millions, the general adult and pediatric populations may elect to wear SMs and FPUs, respectively, in the case of a pandemic or a bio-terrorist attack. When a person dons a PPE, gaps are created between the wearer's face and the PPE, and aerosols leaking through these gaps can be an important contributor to the risk of infection compared to filtered aerosols. To understand and quantify the contribution of leakage of aerosols through gaps, with particular emphasis on SMs and FPUs, this study investigated leakage of charge-neutralized, polydispersed, dried sodium-chloride aerosols across different brands of PPE. Different breathing rates, aerosol particle sizes, and gap sizes were considered. A few major findings of this study were: (a) leakage, is not a strong function of sub-micron aerosol size; (b) for the same gap size, leakage of aerosols through surgical respirators can often be higher than in SMs and FPUs; and (c) as the gap size increases, the increase in leakage through surgical respirators is higher compared for SMs and FPUs, implying that some SMs and FPUs that possess electret layers may be preferable to N95s that have not been fit-tested. The results obtained can also be used to explain conflicting findings from clinical studies on the effectiveness of SMs when compared to N95s and can be input into risk-assessment models to determine the increase in infection rate resulting from deployment of PPE under less-than-ideal conditions.

Herd protection effect of N95 respirators in healthcare workers

Objective

To determine if there was herd protection conferred to unprotected healthcare workers (HCWs) by N95 respirators worn by colleagues.

Methods

Data were analysed from a prospective cluster randomized clinical trial conducted in Beijing, China between 1 December 2008 and 15 January 2009. A minimum compliance level (MCL) of N95 respirators for prevention of clinical respiratory illness (CRI) was set based on various compliance cut-offs. The CRI rates were compared between compliant (≥MCL) and non-compliant (<MCL) N95 wearers by ward, and between non-compliant wearers and control subjects who did not wear masks.

Results

Data were analysed from 949 HCWs who wore N95 respirators and 125 HCWs who did not wear masks. At 50% MCL there were no significant differences in the CRI rates between compliant and non-compliant N95 wearers by ward. In multivariate analysis, the CRI rate in non-compliant HCWs was significantly lower compared with controls (relative risk 0.26; 95% confidence interval 0.08, 0.82).

Conclusion

This study suggests herd protection from use of N95 respirators by colleagues within a hospital ward.