Effectiveness of N95 respirators versus surgical masks against influenza: A systematic review and meta-analysis

Protective face mask: an effective weapon against SARS-CoV-2 with controlled environmental pollution

Masks are face coverings that give protection from infectious agents, airborne pathogens, bacteria, viruses, surgical fog, dust, and other chemical hazards by acting as a barrier between the wearer and the environment. In the COVID-19 pandemic, this major personal protective equipment's became essential part of our daily life. The aim of this review is to analyze and discuss the different types of masks with their pros and cons, manufacturing procedures, evaluation criteria, and application with some of the sterilization process for reuse and smart mask. The review used a thorough examination of the literature to analyze the preventive effects of surgical, N95, smart mask, and potential environmental damage from those masks. Several studies and evidence were also examined to understand the efficiency of different mask on different environment. N95 respirators are capable of filtering out non-oil-based 95% air-born particles, and surgical masks act as a protective barrier between the wearer and the environment. The application of spoon bond and melt blown techniques in the fabrication process of those masks improves their protective nature and makes them lightweight and comfortable. But the high demand and low supply forced users to reuse and extend their use after sterilizations, even though those masks are recommended to be used once. Universal masking in the SARS-COV-2 pandemic increased the chance of environmental pollution, so the application of smart masks became essential because of their high protection power and self-sterilizing and reusing capabilities.

Rapid review: A review of methods and recommendations based on current evidence

Rapid review (RR) could accelerate the traditional systematic review (SR) process by simplifying or omitting steps using various shortcuts. With the increasing popularity of RR, numerous shortcuts had emerged, but there was no consensus on how to choose the most appropriate ones. This study conducted a literature search in PubMed from inception to December 21, 2023, using terms such as "rapid review" "rapid assessment" "rapid systematic review" and "rapid evaluation". We also scanned the reference lists and performed citation tracking of included impact studies to obtain more included studies. We conducted a narrative synthesis of all RR approaches, shortcuts and studies assessing their effectiveness at each stage of RRs. Based on the current evidence, we provided recommendations on utilizing certain shortcuts in RRs. Ultimately, we identified 185 studies focusing on summarizing RR approaches and shortcuts, or evaluating their impact. There was relatively sufficient evidence to support the use of the following shortcuts in RRs: limiting studies to those published in English-language; conducting abbreviated database searches (e.g., only searching PubMed/MEDLINE, Embase, and CENTRAL); omitting retrieval of grey literature; restricting the search timeframe to the recent 20 years for medical intervention and the recent 15 years for reviewing diagnostic test accuracy; conducting a single screening by an experienced screener. To some extent, the above shortcuts were also applicable to SRs. This study provided a reference for future RR researchers in selecting shortcuts, and it also presented a potential research topic for methodologists.

Knowledge, Attitudes, and Practices of Hand Hygiene, Mask Use, and Social Distancing among Public Hospital and Polyclinic Nurses in Barbados during the Coronavirus 2019 Pandemic

BACKGROUND

Nurses are essential members of the healthcare workforce and were among the first-line carers for patients in community and hospital settings during the COVID-19 pandemic. As a result, they were at a heightened risk of infection, resulting in several reported deaths among nursing staff. Several preventive measures were adopted to contain the spread of the COVID-19 virus. This study aims to explore the knowledge, attitudes, and practices (KAP) of nurses regarding hand hygiene, mask wearing, and social distancing measures in healthcare settings in Barbados during the COVID-19 pandemic.

METHOD

An online survey of nurses working in public hospitals and polyclinics (public primary care clinics) in Barbados from March 2021 to December 2021 was conducted. A nonsystematic convenience sampling method was employed to recruit nurses who were readily available and willing to participate. A questionnaire captured the sociodemographic information and knowledge and practices related to hand hygiene, the use of face masks, and social distancing. Each correct response received one mark. Overall knowledge scores were categorized as poor (<60%), average (60-80%), or good (>80-100%).

RESULTS

Of the 192 participants, the majority were female (82.8%) and had >5 years of experience (82%). The findings revealed that 45.8% had poor knowledge of hand hygiene, and that the knowledge of 43.8% of respondents was average. Multivariable logistic regression showed that, after adjustment for age and gender, registered nurses had 2.1 times increased odds (95% confidence interval 1.0, 4.2) of having good knowledge compared to other nursing categories. Regarding mask wearing, 53.6% of nurses had average knowledge, and 27.1% had good knowledge. Multivariable logistic regression showed that, after adjustment for age and gender, registered nurses had 3.3 times increased odds (95% confidence interval 1.5, 7.4) of having good knowledge compared to nursing assistants. A total of 68.6% of respondents followed the correct steps of handwashing every time, and 98.3% wore a mask in public places. More than half of the nurses (51.2%) kept a safe distance from others to avoid spreading SARS-CoV-2; one-third were in a crowded place(s) in the past three months, and 55.8% usually followed guidelines for social isolation as recommended by the WHO.

CONCLUSIONS

The study identified knowledge deficiencies related to hand hygiene and wearing masks among nurses. It is imperative to provide additional training on infection control measures.

Initial evidence that skin health deteriorates for younger age groups and with increased daily use of face masks for healthcare professionals at a dental hospital in the United Kingdom

OBJECTIVE

To determine the incidence and site of any adverse effects of wearing face masks via an online questionnaire.

METHODS

Healthcare workers in a dental hospital who wear Respiratory Protective Equipment (RPE) were invited to participate. An online questionnaire was used to identify adverse effects as a result of wearing face masks and possible remedies.

RESULTS

Red marks (72.1 %) and indentations (66.7 %) were the most frequently reported issues with increased use of the RPE. The bridge of the nose and cheeks were the most frequently reported sites of facial skin problems, such as blanching (54.1 % and 42.2 %, respectively) and pressure damage (42.3 % and 24.3 %, respectively). Overall perceived facial skin health deteriorated strongly and significantly (P < 0.001) following the use of RPE, where the mean skin health score (0 = best possible skin health and 10 = worst possible skin health) increased from 2.68 to 4.76. Broadly, there was increased discomfort with increased hours of use of RPE per day (P = 0.049). 71 % of participants said that they generally felt safe or very safe using RPE.

CONCLUSION

The facial skin health of respondents deteriorated strongly after the use of RPE. Guidelines for using RPE should be made clearer. A greater range of face mask sizes or bespoke masks should be made available to improve the fit and wearability, as well as to reduce the frequency and incidence of surface skin problems.

CLINICAL SIGNIFICANCE

This study has identified the factors influencing adverse skin reactions from face mask use, which can be used to inform face mask designers and manufacturers to improve the fit and wearability of face masks.

Aerosol-generating procedures and associated control/mitigation measures: Position paper from the Canadian Dental Hygienists Association and the American Dental Hygienists' Association

Background

Since the outbreak of COVID-19, how to reduce the risk of spreading viruses and other microorganisms while performing aerosolgenerating procedures (AGPs) has become a challenging question within the dental and dental hygiene communities. The purpose of this position paper is to summarize the evidence of the effectiveness of various mitigation methods used to reduce the risk of infection transmission during AGPs in dentistry.

Methods

The authors searched 6 databases-MEDLINE, EMBASE, Scopus, Web of Science, Cochrane Library, and Google Scholar-for relevant scientific evidence published between January 2012 and December 2022 to answer 6 research questions about the risk of transmission, methods, devices, and personal protective equipment (PPE) used to reduce contact with microbial pathogens and limit the spread of aerosols.

Results

A total of 78 studies fulfilled the eligibility criteria. The literature on the risk of infection transmission including SARS-CoV-2 between dental hygienists and their patients is limited. Although several mouthrinses are effective in reducing bacterial contaminations in aerosols, their effectiveness against SARS-CoV-2 is also limited. The combined use of eyewear, masks, and face shields is effective in preventing contamination of the facial and nasal region while performing AGPs. High-volume evacuation with or without an intraoral suction, low-volume evacuation, saliva ejector, and rubber dam (when appropriate) have shown effectiveness in reducing aerosol transmission beyond the generation site. Finally, the appropriate combination of ventilation and filtration in dental operatories is effective in limiting the spread of aerosols.

Discussion and Conclusion

Aerosols produced during clinical procedures can pose a risk of infection transmission between dental hygienists and their patients. The implementation of practices supported by available evidence will ensure greater patient and provider safety in oral health settings. More studies in oral health clinical environments would shape future practices and protocols, ultimately to ensure the delivery of safe clinical care.

Measuring the effects of respiratory protective equipment and other protectors in preventing the scattering of vocalization droplets

This study was conducted to quantitatively examine the effects of respiratory protective equipment (respirators) and various other types of protectors in preventing the scattering of vocalization droplets. Each of 12 adult male volunteers was asked to vocalize intermittently for 1 min at a target intensity of approximately 100 dBA in an experimental room adjusted to a humidity of approximately 60-70%. The subjects vocalized while wearing respirators, other types of protectors, or no protectors at all. The droplet concentration in a particle size range of 0.3 to 10 μm was measured under each experimental condition, and the transmitted particle concentration and penetration were calculated. The concentration and penetration of particles transmitted from the respirators were lower than those transmitted from the other protectors examined. The probability of infection reduction through the use of the protectors was estimated from the data obtained on the effectiveness of the protectors in preventing the scattering of droplets. We concluded that there is no need for additional droplet scattering prevention in various work settings when appropriate respirators are used under optimal conditions.

Design and testing of a sew-free origami mask for improvised respiratory protection

Respiratory aerosols with diameters smaller than 100μm have been confirmed as important vectors for the spread of diseases such as SARS-CoV-2. While disposable and cloth masks afford some protection, they are typically inefficient at filtering these aerosols and require specialized fabrication devices to produce. We describe a fabrication technique that makes use of a folding procedure (origami) to transform any filtration material into a mask. These origami masks can be fabricated by non-experts at minimal cost and effort, provide adequate filtration efficiencies, and are easily scaled to different facial sizes. Using a mannequin fit test simulator, we demonstrate that these masks can provide filtration efficiencies of over 90% while simultaneously providing greater comfort as demonstrated by pressure drops of <20 Pa. We also quantify mask leakage by measuring the variations in filtration efficiency and pressure drop when masks are sealed to the mannequin face compared to when the mask is unsealed but positioned to achieve the best fit. While leakage generally trended with pressure drop, some of the best performing mask media achieved <10% reduction in filtration efficiency due to leakage. Because this mask can provide high filtration efficiencies at low pressure drop compared to commercial alternatives, it is likely to promote greater mask wearing tolerance and acceptance.

Selective and deceptive citation in the construction of dueling consensuses

The COVID-19 pandemic provides a unique opportunity to study science communication and, in particular, the transmission of consensus. In this study, we show how "science communicators," writ large to include both mainstream science journalists and practiced conspiracy theorists, transform scientific evidence into two dueling consensuses using the effectiveness of masks as a case study. We do this by compiling one of the largest, hand-coded citation datasets of cross-medium science communication, derived from 5 million Twitter posts of people discussing masks. We find that science communicators selectively uplift certain published works while denigrating others to create bodies of evidence that support and oppose masks, respectively. Anti-mask communicators in particular often use selective and deceptive quotation of scientific work and criticize opposing science more than pro-mask communicators. Our findings have implications for scientists, science communicators, and scientific publishers, whose systems of sharing (and correcting) knowledge are highly vulnerable to what we term adversarial science communication.

[Respiratory infections: Additional transmission-based precautions in healthcare facilities]

INTRODUCTION

In health care, measures against cross-transmission of microorganisms are codified by standard precautions, and if necessary, they are supplemented by additional precautions.

STATE OF THE ART

Several factors impact transmission of microorganisms via the respiratory route: size and quantity of the emitted particles, environmental conditions, nature and pathogenicity of the microorganisms, and degree of host receptivity. While some microorganisms necessitate additional airborne or droplet precautions, others do not.

PROSPECTS

For most microorganisms, transmission patterns are well-understood and transmission-based precautions are well-established. For others, measures to prevent cross-transmission in healthcare facilities remain under discussion.

CONCLUSIONS

Standard precautions are essential to the prevention of microorganism transmission. Understanding of the modalities of microorganism transmission is essential to implementation of additional transmission-based precautions, particularly in view of opting for appropriate respiratory protection.

The real bacterial filtration efficiency to evaluate the effective protection of facemasks used for the prevention of respiratory diseases

The real protection offered by facemasks to control the transmission of respiratory viruses is still undetermined. Most of the manufacturing regulations, as well as scientific studies, have focused on studying the filtration capacity of the fabrics from which they are made, ignoring the air that escapes through the facial misalignments, and which depends on the respiratory frequencies and volumes. The objective of this work was to define a Real Bacterial Filtration Efficiency for each type of facemask, considering the bacterial filtration efficiency of the manufacturers and the air that passes through them. Nine different facemasks were tested on a mannequin with three gas analyzers (measuring inlet, outlet, and leak volumes) inside a polymethylmethacrylate box. In addition, the differential pressure was measured to determine the resistance offered by the facemasks during the inhalation and exhalation processes. Air was introduced with a manual syringe for 180 s simulating inhalations and exhalations at rest, light, moderate and vigorous activities (10, 60, 80 and 120 L/min, respectively). Statistical analysis showed that practically half of the air entering to the system is not filtered by the facemasks in all intensities (p < 0.001, ηp² = 0.971). They also showed that the hygienic facemasks filter more than 70% of the air, and their filtration does not depend on the simulated intensity, while the rest of the facemasks show an evidently different response, influenced by the amount of air mobilized. Therefore, the Real Bacterial Filtration Efficiency can be calculated as a modulation of the Bacterial Filtration Efficiencies that depends on the type of facemask. The real filtration capacity of the facemasks has been overestimated during last years since the filtration of the fabrics is not the real filtration when the facemask is worn.

Effects of the Use of N95 Masks on the Vital Signs of Healthy Healthcare Workers During the COVID-19 Pandemic: A Hospital-Based Cross-Sectional Study

BACKGROUND AND AIMS

The N95 filtering facepiece respirator (FR) is the most commonly recommended respiratory protection used in healthcare settings. However, concerns have been raised about its use because it can increase respiratory resistance and dead space. The primary objective of this study was to determine the effect of wearing N95 masks on the vital signs, i.e., oxygen saturation, pulse rate, and respiratory rate, of the participant health workers. Our secondary objective was to assess the subjective feeling of discomfort when wearing N95 masks.

METHODS

The study participants were healthy healthcare workers taking care of coronavirus disease 2019 (COVID-19)-infected pediatric cases who did at least six hours of continuous shift duty in the pediatric COVID-19 ward at a tertiary care hospital in the eastern part of India. They were evaluated for vital signs at various time intervals while wearing N95 masks. Subjective discomfort at any point in time was also noted.

RESULTS

We found a significant variation in the mean oxygen saturation (SpO₂) and heart rate (HR) reduction across the four different points. The pair-wise comparison showed a small but significant decrease in the mean SpO₂ of 98.3% (1.1) at six hours as compared with a mean SpO₂ of 98.7% (0.9) at three hours. Similarly, a significant increase was noted for a mean HR of 84.7 bpm (11.2) at six hours compared with a baseline of 82.3 bpm (9.2) and 83.2 bpm (8.8) at three hours.

CONCLUSION

The continuous use of an N95 mask leads to a mild increase in respiratory rate. However, heart rate and oxygen saturation vary significantly at different points in time after N95 mask use.

Major Update: Masks for Prevention of SARS-CoV-2 in Health Care and Community Settings-Final Update of a Living, Rapid Review

BACKGROUND

Optimal use of masks for preventing COVID-19 is unclear.

PURPOSE

To update an evidence synthesis on N95, surgical, and cloth mask effectiveness in community and health care settings for preventing SARS-CoV-2 infection.

DATA SOURCES

MEDLINE, EMBASE, medRxiv (3 June 2022 to 2 January 2023), and reference lists.

STUDY SELECTION

Randomized trials of interventions to increase mask use and risk for SARS-CoV-2 infection and observational studies of mask use that controlled for potential confounders.

DATA EXTRACTION

Two investigators sequentially abstracted study data and rated quality.

DATA SYNTHESIS

Three randomized trials and 21 observational studies were included. In community settings, mask use may be associated with a small reduced risk for SARS-CoV-2 infection versus no mask use, on the basis of 2 randomized trials and 7 observational studies. In routine patient care settings, surgical masks and N95 respirators may be associated with similar risk for SARS-CoV-2 infection, on the basis of 1 new randomized trial with some imprecision and 4 observational studies. Evidence from observational studies was insufficient to evaluate other mask comparisons due to methodological limitations and inconsistency.

LIMITATION

Few randomized trials, studies had methodological limitations and some imprecision, suboptimal adherence and pragmatic aspects of randomized trials potentially attenuated benefits, very limited evidence on harms, uncertain applicability to Omicron variant predominant era, meta-analysis not done due to heterogeneity, unable to formally assess for publication bias, and restricted to English-language articles.

CONCLUSION

Updated evidence suggests that masks may be associated with a small reduction in risk for SARS-CoV-2 infection in community settings. Surgical masks and N95 respirators may be associated with similar infection risk in routine patient care settings, but a beneficial effect of N95 respirators cannot be ruled out.

PRIMARY FUNDING SOURCE

None.

COVID-19 knowledge deconstruction and retrieval: an intelligent bibliometric solution

COVID-19 has been an unprecedented challenge that disruptively reshaped societies and brought a massive amount of novel knowledge to the scientific community. However, as this knowledge flood continues surging, researchers have been disadvantaged by not having access to a platform that can quickly synthesize emerging information and link the new knowledge to the latent knowledge foundation. Aiming to fill this gap, we propose a research framework and develop a dashboard that can assist scientists in identifying, retrieving, and understanding COVID-19 knowledge from the ocean of scholarly articles. Incorporating principal component decomposition (PCD), a knowledge mode-based search approach, and hierarchical topic tree (HTT) analysis, the proposed framework profiles the COVID-19 research landscape, retrieves topic-specific latent knowledge foundation, and visualizes knowledge structures. The regularly updated dashboard presents our research results. Addressing 127,971 COVID-19 research papers from PubMed, the PCD topic analysis identifies 35 research hotspots, along with their inner correlations and fluctuating trends. The HTT result segments the global knowledge landscape of COVID-19 into clinical and public health branches and reveals the deeper exploration of those studies. To supplement this analysis, we additionally built a knowledge model from research papers on the topic of vaccination and fetched 92,286 pre-Covid publications as the latent knowledge foundation for reference. The HTT analysis results on the retrieved papers show multiple relevant biomedical disciplines and four future research topics: monoclonal antibody treatments, vaccinations in diabetic patients, vaccine immunity effectiveness and durability, and vaccination-related allergic sensitization.

Electronic textiles: New age of wearable technology for healthcare and fitness solutions

Sedentary lifestyles and evolving work environments have created challenges for global health and cause huge burdens on healthcare and fitness systems. Physical immobility and functional losses due to aging are two main reasons for noncommunicable disease mortality. Smart electronic textiles (e-textiles) have attracted considerable attention because of their potential uses in health monitoring, rehabilitation, and training assessment applications. Interactive textiles integrated with electronic devices and algorithms can be used to gather, process, and digitize data on human body motion in real time for purposes such as electrotherapy, improving blood circulation, and promoting wound healing. This review summarizes research advances on e-textiles designed for wearable healthcare and fitness systems. The significance of e-textiles, key applications, and future demand expectations are addressed in this review. Various health conditions and fitness problems and possible solutions involving the use of multifunctional interactive garments are discussed. A brief discussion of essential materials and basic procedures used to fabricate wearable e-textiles are included. Finally, the current challenges, possible solutions, opportunities, and future perspectives in the area of smart textiles are discussed.

Perceptions, Knowledge, and Experiences of Using Face Masks among Egyptian Healthcare Workers during the COVID-19 Pandemic: A Cross-Sectional Study

Using face masks appropriately is important for preventing the community spread of respiratory infections. A cross-sectional study was conducted to evaluate the knowledge level and experience of using face masks between healthcare teams to protect them and limit the spread of COVID-19 infection. A structured questionnaire was distributed to 228 healthcare members in July–December 2021. It was divided into two sections and consisted of 29 questions for a total possible score of 0 to 29. The first section was related to perceptions and knowledge about face masks (13 items); the second was related to the experience of using face masks (16 items). The average score of this questionnaire was 23.21/29 with respect to the knowledge about face masks and their proper use techniques. The healthcare team studied had satisfactory knowledge about face mask use techniques, and the study shed light on their unsatisfactory practices. Following instructions is very vital to protecting the person wearing the mask and preventing the spread of infection during health care by blocking droplets produced by speaking or coughing. Providing the healthcare teams with knowledge and experience about how to use face masks during the pandemic is critical to increase their awareness and practice in using face masks and prevent the infection from spreading.

Carbon footprint assessment of face masks in the context of the COVID-19 pandemic: Based on different protective performance and applicable scenarios

Widespread concerns have been raised about the huge environmental burden caused by massive consumption of face masks in the context of the COVID-19 pandemic. However, most of the existing studies only focus on the environmental impact associated with the product itself regardless of the actual usage scenarios and protective performance of products, resulting in unrealistic conclusions and poor applicability. In this context, this study integrated the product performance into the existing carbon footprint assessment methodology, with focus on the current global concerns regarding climate change. Computational case studies were conducted for different mask products applicable to the scenarios of low-, medium- and high-risk levels. The results showed that reusable cotton masks and disposable medical masks suitable for low-risk settings have a total carbon footprint of 285.484 kgCO₂-eq/FU and 128.926 kgCO₂-eq/FU respectively, with a break-even point of environmental performance between them of 16.886, which implies that cotton masks will reverse the trend and become more environmentally friendly after 17 washes, emphasizing the importance of improving the washability of cotton masks. Additionally, the total carbon footprints of disposable surgical masks and KN95 respirators were 154.328 kg CO₂-eq/FU and 641.249 kg CO₂-eq/FU respectively, while disposable medical masks and disposable surgical masks were identified as alternatives with better environmental performance in terms of medium- and high-risk environments respectively. The whole-life-cycle oriented carbon footprint evaluation further indicated that the four masks have greater potential for carbon emission reduction in the raw material processing and production processes. The results obtained in this study can provide scientific guidance for manufacturers and consumers on the production and use of protective masks. Moreover, the proposed model can be applied to other personal protective equipment with similar properties, such as protective clothing, in the future.

Case study of the Beijing 2022 Olympic Winter Games: Implications for global mass gathering events amidst the COVID-19 pandemic

Objective

This study aimed to evaluate the public health countermeasures against coronavirus disease 2019 (COVID-19) that are important for organizing mass gathering events (MGEs) during a pandemic and to identify the practices suitable for application at future MGEs.

Methods

This study analyzed data from the Beijing 2022 Olympic Winter Games. The aforementioned analysis was conducted from the viewpoints of overseas stakeholders and Chinese residents. The comprehensive set of countermeasures established to prevent the transmission of the COVID-19 pandemic comprised the bubble strategy, the three-layer testing strategy (pre-departure testing, testing at the airport, and daily screening), the mandatory wearing of N95 masks, and mandatory vaccination.

Findings

A total of 437 positive cases within the bubble were reported during the Games, of which 60.6% were detected through screening at the airport and 39.4% were detected through routine screening. Nearly, 92.0% of the positive cases were detected within 7 days of arrival in China, and 80.8% of the cases had already been identified before the Opening Ceremony of the Games. Outside the bubble, no Games stakeholders were infected and no spectator contracted COVID-19. The bubble strategy, the three-layer testing strategy, the mandatory wearing of N95 masks, and mandatory vaccination are promising countermeasures to prevent the transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) during MGEs.

Conclusion

Public health countermeasures introduced during the Beijing 2022 Olympic Winter Games were proven to be useful. The success in delivering and organizing the Games instills confidence and leaves a public health legacy for future MGEs amid the pandemic of COVID-19 or future emerging infectious diseases.

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.

Unraveling the potential human health risks from used disposable face mask-derived micro/nanoplastics during the COVID-19 pandemic scenario: A critical review

With the global spread of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), disposable face masks (DFMs) have caused negative environmental impacts. DFMs will release microplastics (MPs) and nanoplastics (NPs) during environmental degradation. However, few studies reveal the release process of MPs/NPs from masks in the natural environment. This review presents the current knowledge on the abiotic and biotic degradation of DFMs. Though MPs and NPs have raised serious concerns about their potentially detrimental effects on human health, little attention was paid to their impacts on human health from DFM-derived MPs and NPs. The potential toxicity of mask-derived MPs/NPs, such as gastrointestinal toxicity, pneumotoxicity, neurotoxicity, hepatotoxicity, reproductive and transgenerational toxicity, and the underlying mechanism will be discussed in the present study. MPs/NPs serve as carriers of toxic chemicals and pathogens, leading to their bioaccumulation and adverse effects of biomagnification by food chains. Given human experiments are facing ethical issues and animal studies cannot completely reveal human characteristics, advanced human organoids will provide promising models for MP/NP risk assessment. Moreover, in-depth investigations are required to identify the release of MPs/NPs from discarded face masks and characterize their transportation through the food chains. More importantly, innovative approaches and eco-friendly strategies are urgently demanded to reduce DFM-derived MP/NP pollution.

Compliance with wearing facemasks by university teaching staff during the second wave of COVID-19 pandemic: a cross sectional study

Objective

We aimed to explore compliance with and barriers to wearing facemasks at the workplace among university teaching staff in Egypt.

Methods

An online survey was shared with teaching staff members at 11 public and 12 private Egyptian universities and high institutes, and 218 responses were received. All participants were asked about beliefs related to wearing facemasks. For participants who taught in-person classes, compliance with and barriers to wearing facemasks at the workplace were assessed. Compliance level was classified into: Non-compliance, inadequate and adequate, based on the degree of adherence to having facemasks on and not taking them off at five main work settings. We compared demographic characteristics, beliefs, and barriers scores across compliance levels.

Results

Most participants (81.7%) believed that facemasks reduce infection risk to others and 74.3% believed facemasks can reduce risk to the wearer. Around 80% of the respondents who taught in-person classes wore facemasks, but only 37.8% met the criteria of adequate compliance. Difficulty breathing and impaired communication were cited as major barriers by 42.2% and 30.3% of in-person class tutors respectively. The risk of reporting COVID-19 like symptoms among non-compliant participants was double the risk among those with adequate compliance (45.9% vs 25.7% respectively). Adequate compliance was significantly associated with higher positive beliefs scores and lower barriers scores.

Conclusion

Adequate compliance with wearing facemasks at the workplace was low. Addressing negative beliefs may improve compliance. Difficulty breathing, and impaired communication were important barriers, therefore we recommend replacing in-person interactions with online classes whenever applicable.

Supplementary Information

The online version contains supplementary material available at 10.1007/s44155-022-00011-3.

The Effect of Face Mask, Air Temperature, and Humidity on COVID-19 Transmission: A Systematic Review and Meta-analysis

Context: At the beginning of the COVID-19 pandemic, the effects of personal protective equipment (PPE) such as face masks, as well as environmental conditions, including temperature and humidity changes, were discussed due to the lack of effective medicine. Methods: The preferred reporting items for systematic reviews and meta-analysis (PRISMA) were implemented to conduct the present systematic review. The articles were selected from papers published by May 2020 in PubMed, Web of Science, Science Direct, Scopus, and Google Scholar databases. This meta-analysis estimated relative risk (RR) and pooled mean depicted as effect size (ES) using the random or fixed effects methods. Results: Ten studies met inclusion criteria, four of which addressed the effect of face masks and six of which dealt with temperature and humidity changes. This eta-analysis study showed that wearing face masks against the COVID-19 virus had a remarkable safety impact with RR (%95 CI) 8.56 (2.10 - 34.90), (I2 = %0.0 P = 0.999), and the pooled mean changes in temperature and humidity were estimated to be with ES (%95 CI) 9.03 (4.32 - 13.74), (I2 = %99.7, P = 0.0001) and with ES (%95 CI) 56.82 (46.12 - 67.51), ( I2 = %99.3, P = 0.0001) during the outbreak of the COVID-19. Conclusions: The findings of this systematic review and meta-analysis illustrate the effectiveness of face masks, in general, in preventing the transmission of the COVID-19 virus. According to the findings, temperature and humidity changes do not increase the outbreak of the COVID-19 virus.

A review on the effectiveness of various masks in protection against COVID-19

As of June1st 2021, more than 17 crore people have been infected with COVID-19 across the globe, and almost 3 crore people have been infected in India. The virus can spread through even normal actions like talking with particle emission rates inversely correlating with word frequency and volume, which can be reduced by covering the mouth. However, there is debate concerning the effectiveness of the various face mask types in preventing respiratory infections. Many have reported that wearing a mask is uncomfortable, especially when worn for long hours and while performing strenuous activities. Another disease that has raised its head is mucormycosis. However, COVID-19 can be a serious infection in many, with many fatalities. It is not yet clear how much protection vaccines give, and in a hugely populated country like India, it may be very difficult to vaccinate the whole population. Moreover, the vaccination for pediatric groups has just started. So, it is imperative to wear masks that can be protective against infection. However, some people believe that a straightforward cotton mask is insufficient. We set out to analyze the efficacy of masks through this investigation. According to the results of this systematic review, there are no studies that give conclusive evidence that using face masks as recommended by current public health guidelines will stop this condition. This is a significant discovery that should be communicated to the scientific community and calls into question the rationale for inconsistent and differing public health recommendations.

COVID-19 Risk Management in Dental Offices: A Review Article

BACKGROUND: As all the dental staff, including nurses and practitioners, are exposed to various routes of contamination due to the novel COVID-19 virus, which is still unknown to the scientific world, developing strategies to reduce the risk of transmission and decontaminate surfaces in a dental office would be of high importance. Although there is still insufficient data on managing this virus in dental offices, several studies have suggested protocols for improving care. AIM: This study aimed to review present investigations and reach a conclusion on what we know and need to know to combat this virus. MATERIALS AND METHODS: In this review, Scopus, PubMed, and MEDLINE databases were searched using the keywords “COVID-19,” “SARS-CoV-2,” “Medical Disinfectants,” “Personal Protective Equipment’s,” and “Surface Decontamination.” Articles were reviewed, and finally, relevant articles published during 2000–2022 were included in the final paper. RESULTS: The present research concluded that using a combination of the face shield and N95 masks protected the eyes, nose, and mouth. To have more efficient protection, water-resistant long-sleeved gowns and gloves were highly suggested. To overcome aerosols, high-performance air filters and ultraviolet were found quite effective. Allowing the patient to use antiseptic mouthwash before starting the treatment could reduce oral microorganisms and the following airborne contamination. CONCLUSION: This review has gathered all available data regarding dentistry and COVID-19 in order to conclude what has been achieved yet in the prevention of this virus through dental offices; however, more investigations are needed to have a definitive protocol against the virus.

The application of enhanced recovery after surgery in minimally invasive gastrectomy for gastric cancer: a meta-analysis of randomized controlled trials

OBJECTIVE

We aimed to investigate the efficacy and safety of enhanced recovery after surgery (ERAS) for patients with gastric cancer undergoing minimally invasive surgery (MIS).

METHODS

We searched the PubMed, Cochrane Library, Web of Science, Embase, CNKI, VIP, WanFang, and CBM for relevant RCTs from the database inception until December 2021, for studies that compared the ERAS and traditional care (TC) in MIS for gastric cancer.

RESULTS

A total of 25 RCTs comprising 2809 patients were included in this study. When compared with the traditional care TC group, the ERAS group had a shorter postoperative hospital stay [MD = -1.88,95%CI (-2.22, -1.55), P < 0.00001] and an earlier time at first postoperative flatus [MD = -18.12,95%CI (-21.45,-14.80), P < 0.00001] along with lower medical costs [SMD = -0.64, 95% CI (-0.85, -0.43), P < 0.00001] and an overall reduction in postoperative complication rates [RR = 0.55, 95% CI (0.44, 0.69), P < 0.00001]. However, the difference in the readmission rates    was not significant.

CONCLUSIONS

ERAS can shorten the postoperative hospital stay, hasten the first postoperative flatus and reduce medical costs and overall postoperative complication rate without increasing readmission rates. Therefore, the ERAS protocol is preferable for gastric cancer patients undergoing MIS.

Surface disinfection and protective masks for SARS-CoV-2 and other respiratory viruses: A review by SIdP COVID-19 task force

OBJECTIVES

Primary focused question for this systematic review (SR) was "Which is the evidence about surfaces decontamination and protection masks for SARS-Cov-2 in dental practice?" Secondary question was "Which is the evidence about surfaces decontamination and protection masks against airborne pathogens and directly transmitted viral pathogens causing respiratory infections?"

MATERIALS AND METHODS

PRISMA guidelines were used. Studies on surface decontamination and protective masks for SARS-CoV-2 in dental practice were considered. Studies on other respiratory viruses were considered for the secondary question.

RESULTS

No studies are available for SARS-CoV-2. Four studies on surface disinfection against respiratory viruses were included. Ethanol 70% and sodium hypochlorite 0,5% seem to be effective in reducing infectivity by > 3log TCID. Four RCTs compared different types of masks on HCW. The single studies reported no difference for laboratory-diagnosed influenza, laboratory-diagnosed respiratory infection, and influenza-like illness. A meta-analysis was not considered appropriate.

CONCLUSIONS

There is lack of evidence on the efficacy of surface disinfection and protective masks to reduce the spread of SARS-CoV-2 or other respiratory viruses in dentistry. However, the consistent use of respirator and routine surface disinfection is strongly suggested. There is urgent need of data on the efficacy of specific protection protocols for dental HCW against viral infections.

Effects of COVID-19-targeted nonpharmaceutical interventions on children's respiratory admissions in China: a national multicenter time series study

OBJECTIVES

To estimate the impact of nonpharmaceutical interventions (NPIs) targeted at the COVID-19 pandemic on the admission number of respiratory diseases, including pneumonia, acute bronchitis & bronchiolitis, and acute upper respiratory infections (AURIs) for children in China.

METHODS

Continuous hospitalization records aged 0-18 years from January 1, 2016, to December 31, 2020, were collected from 26 tertiary children's hospitals. Interrupted time series analysis with a quasi-Poisson model was conducted with the start time of the COVID-19 pandemic as the interrupted timepoint and the weekly admission numbers of all-cause respiratory disease, pneumonia, acute bronchitis & bronchiolitis, and AURI as the outcome measures. Hospitalizations of childhood neoplasms were analyzed as the reference group.

RESULTS

The reduction in admission numbers following NPIs was -55.0% (-57.9 to -51.9%) for all-cause respiratory diseases, -62.7% (-65.7 to -59.5%) for pneumonia, -48.1% (-53.3 to -42.3%) for bronchitis & bronchiolitis, and -24.3% (-28.6 to -19.8%) for AURI. The effect estimates of NPIs on childhood neoplasms was -29.1% (-33.6 to -24.4%). Stratification analysis showed the reduction was most drastic for children at 4-6 and 7-12 years.

CONCLUSION

The admission number for respiratory diseases among children in China decreased drastically after the implementation of NPIs. NPIs with low socio-economic burdens should be suggested even outside the COVID-19 pandemic.

Nanotechnology Transition Roadmap toward Multifunctional Stimuli-Responsive Face Masks

In recent times, the use of personal protective equipment, such as face masks or respirators, is becoming more and more critically important because of common pollution; furthermore, face masks have become a necessary element in the global fight against the COVID-19 pandemic. For this reason, the main mission of scientists has become the development of face masks with exceptional properties that will enhance their performance. The versatility of electrospun polymer nanofibers has determined their suitability as a material for constructing "smart" filter media. This paper provides an overview of the research carried out on nanofibrous filters obtained by electrospinning. The progressive development of the next generation of face masks whose unique properties can be activated in response to a specific external stimulus is highlighted. Thanks to additional components incorporated into the fiber structure, filters can, for example, acquire antibacterial or antiviral properties, self-sterilize the structure, and store the energy generated by users. Despite the discovery of several fascinating possibilities, some of them remain unexplored. Stimuli-responsive filters have the potential to become products of large-scale availability and great importance to society as a whole.

Efficacy of Vitamin C Supplementation on Chronic Obstructive Pulmonary Disease (COPD): A Systematic Review and Meta-Analysis

Background

In recent years, the pleiotropic roles of antioxidants have drawn extensive attention in various diseases. Vitamin C is a well-known antioxidant, and it has been used to treat patients with chronic obstructive pulmonary disease (COPD). This systematic review and meta-analysis aim to demonstrate the impact of vitamin C supplementation in patients with COPD.

Methods

We searched PubMed, Embase, Cochrane Library, Web of Science, Chinese National Knowledge Infrastructure (CNKI), SinoMed, Wanfang, and China Science and Technology Journal Database (cqvip.com) for eligible randomized controlled trials (RCTs) from their respective inception to May 18^th, 2021, by using the searching terms of COPD, vitamin C, and RCTs. A meta-analysis was performed to evaluate the effects of vitamin C on lung function, antioxidant levels, and nutritional conditions in COPD patients by using Review Manager (Version 5.4).

Results

Ten RCTs including 487 participants were eligible for our study. Meta-analysis results showed that vitamin C supplementation (≥400 mg/day) can significantly improve the forced expiratory volume in one second as a percentage (FEV1%) in COPD (SMD:1.08, 95% CI:0.03, 2.12, P=0.04). Moreover, vitamin C supplementation significantly improved the ratio of forced expiratory volume in 1 second and forced vital capacity (FEV1/FVC) (WMD:0.66, 95% CI: 0.26, 1.06, P=0.001), vitamin C level in serum (SMD:0.63, 95% CI: 0.02, 1.24, P=0.04) and glutathione (GSH) level in serum (SMD:2.47, 95% CI: 1.06, 3.89, P=0.0006). While no statistically significant difference was observed in body mass index (BMI), fat-free mass index (FFMI), vitamin E level and superoxide dismutase (SOD) level in serum.

Conclusion

Vitamin C supplementation could increase the levels of antioxidation in serum (vitamin C and GSH) and improve lung function (FEV1% and FEV1/FVC), especially in patients treated with vitamin C supplementation greater than 400 mg/day. However, further prospective studies are needed to explore the role of vitamin C in improving nutritional status.

COVID-19 Preventive Measure: A Study on “MASK-A Boon or a Bane”

Background. Mask wearing can restrict the spread of respiratory viral transmission during the third wave of the COVID-19 pandemic. Globally, governments have emphasized its use in workplaces and public areas to prevent the transmission routes of corona virus. In spite of the current awareness in the general population, the stringency of wearing the mask lies as an individual’s choices. Subject and Methods. This research work discusses available studies on the types and comparison of masks in the market for use. It includes a short survey conducted with 1,173 anonymized healthy participants primarily devoid of comorbidities. The survey includes the effects of mask wearing, while outdoor with minimal activities like walking and with mild activities like jogging and stretching. Our research further discusses various health effects of wearing a mask, including cardiac output, hypoxemia, hypoxia, and dyspnoea, and how such situations that pose a threat can be consciously avoided. Results. It was found that the majority of people use cloth/fabric reusable mask. There remains scope for better-designed masks and improving health in the mass population by inculcating healthy breathing habits and other relevant exercises that can help people cope up better in this fight against the deadly virus at a larger scale. Conclusion. For most of the survey questions, there was significant correlation between gender and the related responses as there was no significantly observable difference in the nonparametric, unpaired analyses of responses. The main objective of this research work is to initiate more discussions and enhance awareness in natural ways of staying healthy during the pandemic emphasizing mask use. Further progress in this aspect remains a whole new area for future exploration.

Boundary conditions for exhaled airflow from a cough with a surgical or N95 mask

Wearing surgical or N95 masks is effective in reducing the infection risks of airborne infectious diseases. However, in the literature there are no detailed boundary conditions for airflow from a cough when a surgical or N95 mask is worn. These boundary conditions are essential for accurate prediction of exhaled particle dispersion by computational fluid dynamics (CFD). This study first constructed a coughing manikin with an exhalation system to simulate a cough from a person. The smoke visualization method was used to measure the airflow profile from a cough. To validate the setup of the coughing manikin, the results were compared with measured data from subject tests reported in the literature. The validated coughing manikin was then used to measure the airflow boundary conditions for a cough when a surgical mask was worn and when an N95 mask was worn, respectively. Finally, this study applied the developed airflow boundary conditions to calculate person-to-person particle transport from a cough when masks are worn. The calculated exhaled particle patterns agreed well with the smoke pattern in the visualization experiments. Furthermore, the calculated results indicated that, when the index person wore a surgical and a N95 mask, the total exposure of the receptor was reduced by 93.0% and 98.8%, respectively.

Development of saline loaded mask materials, evaluation of the antimicrobial efficacy and survivability of selected bacteria on these mask materials

Objective

Surgical face masks have been recommended by World Health Organization (WHO) during the COVID-19 pandemic. Nowadays wearing masks have become a norm and lifestyle around the globe. The present investigation was carried out to evaluate the feasibility of developing masks loaded with analytical grade sodium chloride (NaCl), Iodized salts (IS) and Omani sea salt (OSS) with or without sodium bicarbonate (NaHCO₃).

Methods

The saline loaded masks were prepared by soaking the middle layer of the mask in 30% (w/v) saline solutions (NaCl, IS, OSS) with or without 10% NaHCO₃ for 24 h followed by drying at room temperature. The prepared saline solutions and its combinations were evaluated for antimicrobial efficacy against the bacteria like Escherichia coli, Pseudomonas aeruginosa, Proteus vulgaris, Salmonella typhi, and Staphylococcus aureus, and antifungal activity against the Penicillium spp. and Rhizopus spp. by agar diffusion. Optical microscopy was employed to observe the formation of salt crystal in the mask material. Survivability of S. aureus and P. aeruginosa was tested on the mask material loaded with 30% OSS + 10% NaHCO₃ at particular time intervals.

Results

The results showed that a combination of 30% OSS + 10% NaHCO₃ exhibited promising antimicrobial activity against all the bacteria as well as Rhizopus spp. compared to the 30% IS + 10% NaHCO₃. Moreover, the middle layer of the mask loaded with saline solutions of 30% OSS + 10% NaHCO₃ or 30% IS + 10% NaHCO₃ have antibacterial activity, particularly for oral microbiome. On dehydration, the masks materials showed the presence of a significant amount of salt crystals. Survivability tests showed that both S. aureus and P. aeruginosa were killed within 3 h of contact with the salt crystals on the mask materials.

Conclusions

A combination of 30% OSS + 10% NaHCO₃ possessed significant antimicrobial activities on the tested microorganisms. Presence of a significant amount of salt crystals on dehydration of the saline loaded masks can be used as an effective protective barrier to infectious respiratory agents.

FOXP4-AS1 May be a Potential Prognostic Biomarker in Human Cancers: A Meta-Analysis and Bioinformatics Analysis

Background

Cancer is one of the leading causes of death worldwide. Early diagnosis can significantly lower cancer-related mortality. Studies have shown that the lncRNA Forkhead box P4 antisense RNA 1 (FOXP4-AS1) is aberrantly expressed in various solid tumors. A meta-analysis was performed to evaluate the correlation of FOXP4-AS1 with the prognosis of cancer patients and determine the clinical value of FOXP4-AS1 as a potential diagnostic marker.

Methods

Correlational studies from the Web of Science, Embase, OVID, Cochrane and PubMed databases were screened (up to April 1, 2021). Meta-analysis was performed using Stata SE12.0 software.

Results

Eleven original studies with 1,332 patients who were diagnosed with a solid cancer (nasopharyngeal carcinoma, hepatocellular carcinoma, colorectal cancer, gastric cancer, osteosarcoma, mantle cell lymphoma, prostate cancer, and pancreatic ductal adenocarcinoma) were included in the meta-analysis. High expression of FOXP4-AS1 was correlated with poor overall survival (OS) (HR = 1.77, 95% CI 1.29-2.44, P < 0.001) and shorter disease-free survival (DFS) (HR = 1.66, 95% CI 1.01-2.72, P = 0.044). Subgroup analysis based on sample size, follow-up time and Newcastle-Ottawa Scale (NOS) score revealed significant differences between FOXP4-AS1 levels and OS (P < 0.05). However, the expression level of FOXP4-AS1 was not significantly correlated with the OS of gastric cancer patients (P = 0.381). High expression of FOXP4-AS1 was predictive of a larger tumor size (OR = 3.82, 95% CI 2.3-6.3, P < 0.001).

Conclusions

Overexpression of FOXP4-AS1 correlates with poor prognosis of cancer patients, and is a potential prognostic biomarker and therapeutic target.

Systematic Review Registration

PROSPERO, identifier CRD42021245267.

Blood gas levels, cardiovascular strain and cognitive performance during surgical mask and filtering face piece application

Mask induced airway resistance and carbon dioxide rebreathing is discussed to impact gas exchange and to induce discomfort and impairments in cognitive performance. N = 23 healthy humans (13 females, 10 males; 23.5 ± 2.1 years) participated in this randomized crossover trial (3 arms, 48-h washout periods). During interventions participants wore either a surgical face mask (SM), a filtering face piece (FFP2) or no mask (NM). Interventions included a 20-min siting period and 20 min steady state cycling on an ergometer at 77% of the maximal heart rate (HR). Hemodynamic data (HR, blood pressure), metabolic outcomes (pulse derived oxygen saturation, capillary carbon dioxide (pCO₂), and oxygen partial pressure (pO₂), lactate, pH, base excess), subjective response (ability to concentrate, arousal, perceived exertion) and cognitive performance (Stroop Test) were assessed. Compared to NM, both masks increased pCO₂ (NM 31.9 ± 3.3 mmHg, SM = 35.2 ± 4.0 mmHg, FFP2 = 34.5 ± 3.8 mmHg, F = 12.670, p < 0.001) and decreased pH (NM = 7.42 ± 0.03, SM = 7.39 ± 0.03, FFP2 = 7.39 ± 0.04, F = 11.4, p < 0.001) during exercise. The FFP2 increased blood pressure during exercise (NM = 158 ± 15 mmHg, SM = 159 ± 16 mmHg, FFP2 = 162 ± 17 mmHg, F = 3.21, p = 0.050), the SM increased HR during sitting (NM = 70 ± 8 bpm, SM = 74 ± 8 bpm, FFP2 = 73 ± 8 bpm, F = 4.70, p = 0.014). No mask showed any comparative effect on other hemodynamic, metabolic, subjective, or cognitive outcomes. Mask wearing leads to slightly increased cardiovascular stress and elevated carbon dioxide levels during exercise but did not affect cognitive performance or wellbeing.

Decontamination Efficiency of Thermal, Photothermal, Microwave, and Steam Treatments for Biocontaminated Household Textiles

With the outbreak of the COVID-19 pandemic, textile laundering hygiene has proved to be a fundamental measure in preventing the spread of infections. The first part of our study evaluated the decontamination efficiency of various treatments (thermal, photothermal, and microwave) for bio contaminated textiles. The effects on textile decontamination of adding saturated steam into the drum of a household textile laundering machine were investigated and evaluated in the second part of our study. The results show that the thermal treatment, conducted in a convection heating chamber, provided a slight reduction in efficiency and did not ensure the complete inactivation of Staphylococcus aureus on cotton swatches. The photothermal treatment showed higher reduction efficiency on contaminated textile samples, while the microwave treatment (at 460 W for a period of 60 s) of bio contaminated cotton swatches containing higher moisture content provided satisfactory bacterial reduction efficiency (more than 7 log steps). Additionally, the treatment of textiles in the household washing machine with the injection of saturated steam into the washing drum and a mild agitation rhythm provided at least a 7 log step reduction in S. aureus. The photothermal treatment of bio contaminated cotton textiles showed promising reduction efficiency, while the microwave treatment and the treatment with saturated steam proved to be the most effective.

P2/N95 filtering facepiece respirators: Results of a large-scale quantitative mask fit testing program in Australian health care workers

Background

In response to the COVID-19 pandemic, 6,287 Australian health care workers (HCWs) were fit tested to N95 filtering facepiece respirators (FFRs). This study determined how readily HCWs were fitted to 8 FFRs and how age and sex influenced testing.

Methods

HCWs were fit tested following the quantitative OSHA protocol. After bivariate analysis, a logistic regression model assessed the effect of FFR model, HCW age and sex on fit test results.

Results

Of 4,198 female and 2,089 male HCWs tested, 93.3% were successfully fitted. Fifty-five percent passed the first FFR, 21% required 2 and 23% required testing on 3 or more models. Males were 15% less likely to pass compared to females (P < .001). Individuals aged 18-29 were significantly more likely to pass compared to colleagues aged 30-59. Cup-style 3M 1860S was the most suitable model (95% CI: 1.94, 2.54) while the duckbill BSN TN01-11 was most likely to fail (95% CI: 0.11, 0.15).

Conclusions

Current N95 FFRs exhibit suboptimal fit such that a large proportion (45%) of HCWs require testing on multiple models. Older age and male sex were associated with significantly higher fit failure rates. QNFT programs should consider HCW characteristics like sex, age, racial and facial anthropometric measurements to improve the protection of the health workforce.

Associations Between Wearing Masks and Respiratory Viral Infections: A Meta-Analysis and Systematic Review

Background

Respiratory viral infections (RVIs) are a major health concern, and some previous studies have shown that wearing masks was effective in preventing RVIs, while others failed to show such effect. Therefore, a systematic review and meta-analysis was conducted to investigate the effectiveness of wearing masks.

Methods

PubMed, ScienceDirect, Web of Science, the Cochrane Library, EMBASE, MEDLINE, China National Knowledge Infrastructure (CNKI), and Chinese Scientific Journal Database (VIP database) were searched for studies evaluating the effectiveness of wearing masks. The risk ratio (RR) was used to measure the effectiveness of wearing masks in preventing RVIs for randomized controlled trials (RCTs) and cohort studies, and the odds ratio (OR) was used for case-control studies. Forest plots were used to visually assess pooled estimates and corresponding 95% CIs. The I2 test was used to examine the heterogeneity, and subgroup analysis was used to explore the possible explanations for heterogeneity or compare the results between subgroups. Sensitivity analysis was conducted to assess robustness of the synthesized results. Begg's test and Egger's test were used to assess the publications bias.

Results

Thirty-one studies (13,329 participants) were eligible for meta-analyses. Overall, the results showed that wearing masks was effective in preventing RVIs. The sensitivity analysis showed that the results of those meta-analyses were robust and reliable. There was no significant publication bias in meta-analysis of case-control studies and most subgroup analyses.

Conclusions

Wearing masks might be effective in preventing RVIs. To reduce their RVI risk, people should wear masks when they go out in public.

Systematic Review Registration

https://www.crd.york.ac.uk/PROSPERO/, identifier: CRD42021296092.

Short and Long-Term Impact of COVID-19 Infection on Previous Respiratory Diseases

On March 11, 2020, the World Health Organization declared Coronavirus Disease 2019 (COVID-19) a pandemic. Till now, it affected 452.4 million (Spain, 11.18 million) persons all over the world with a total of 6.04 million of deaths (Spain, 100,992). It is observed that 75% of hospitalized COVID-19 patients have at least one COVID-19 associated comorbidity. It was shown that people with underlying chronic illnesses are more likely to get it and grow seriously ill. Individuals with COVID-19 who have a past medical history of cardiovascular disorder, cancer, obesity, chronic lung disease, diabetes, or neurological disease had the worst prognosis and are more likely to develop acute respiratory distress syndrome or pneumonia. COVID-19 can affect the respiratory system in a variety of ways and across a spectrum of levels of disease severity, depending on a person's immune system, age and comorbidities. Symptoms can range from mild, such as cough, shortness of breath and fever, to critical disease, including respiratory failure, shock and multi-organ system failure. So, COVID-19 infection can cause overall worsening of these previous respiratory diseases, such as asthma, chronic obstructive pulmonary disease (COPD), interstitial lung disease, etc. This review aims to provide information on the impact of the COVID-19 disease on pre-existing lung comorbidities.

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.

Acoustic characteristics of fricatives, amplitude of formants and clarity of speech produced without and with a medical mask

BACKGROUND

Previous research has found that high-frequency energy of speech signals decreased while wearing face masks. However, no study has examined the specific spectral characteristics of fricative consonants and vowels and the perception of clarity of speech in mask wearing.

AIMS

To investigate acoustic-phonetic characteristics of fricative consonants and vowels and auditory perceptual rating of clarity of speech produced with and without wearing a face mask.

METHODS & PROCEDURES

A total of 16 healthcare workers read the Rainbow Passage using modal phonation in three conditions: without a face mask, with a standard surgical mask and with a KN95 mask (China GB2626-2006, a medical respirator with higher barrier level than the standard surgical mask). Speech samples were acoustically analysed for root mean square (RMS) amplitude (A_RMS ) and spectral moments of four fricatives /f/, /s/, /ʃ/ and /z/; and amplitude of the first three formants (A1, A2 and A3) measured from the reading passage and extracted vowels. Auditory perception of speech clarity was performed. Data were compared across mask and non-mask conditions using linear mixed models.

OUTCOMES & RESULTS

The A_RMS of all included fricatives was significantly lower in surgical mask and KN95 mask compared with non-mask condition. Centre of gravity of /f/ decreased in both surgical and KN95 mask while other spectral moments did not show systematic significant linear trends across mask conditions. None of the formant amplitude measures was statistically different across conditions. Speech clarity was significantly poorer in both surgical and KN95 mask conditions.

CONCLUSIONS & IMPLICATIONS

Speech produced while wearing either a surgical mask or KN95 mask was associated with decreased fricative amplitude and poorer speech clarity.

WHAT THIS PAPER ADDS

What is already known on the subject Previous studies have shown that the overall spectral levels in high frequency ranges and intelligibility are decreased for speech produced with a face mask. It is unclear how different types of the speech signals that is, fricatives and vowels are presented in speech produced with wearing either a medical surgical or KN95 mask. It is also unclear whether ratings of speech clarity are similar for speech produced with these face masks. What this paper adds to existing knowledge Speech data collected using a real-world, clinical and non-laboratory-controlled settings showed differences in the amplitude of fricatives and speech clarity ratings between non-mask and mask-wearing conditions. Formant amplitude did not show significant differences in mask-wearing conditions compared with non-mask. What are the potential or actual clinical implications of this work? Wearing a surgical mask or a KN95 mask had different effects on consonants and vowels. It appeared from the findings in this study that these masks only affected fricative consonants and did not affect vowel production. The poorer speech clarity in these mask-wearing conditions has important implications for speech perception in communication between clinical staff and between medical officers and patients in clinics, and between people in everyday situations. The impact of these masks on speech perception may be more pronounced in people with hearing impairment and communication disorders. In voice evaluation and/or therapy sessions, the effects of wearing a medical mask can occur bidirectionally for both the clinician and the patient. The patient may find it more challenging to understand the speech conveyed by the clinician while the clinician may not perceptually assess patient's speech and voice accurately. Given the significant correlation between clarity ratings and fricative amplitude, improving fricative signals would be useful to improve speech clarity while wearing these medical face masks.

Wearing time and respiratory volume affect the filtration efficiency of masks against aerosols at different sizes

Face masks are critical in preventing the spread of respiratory infections including coronavirus disease 2019 (COVID-19). Different types of masks have distinct filtration efficiencies (FEs) with differential costs and supplies. Here we reported the impact of breathing volume and wearing time on the inward and outward FEs of four different mask types (N95, surgical, single-use, and cloth masks) against various sizes of aerosols. Specifically, 1) Mask type was an important factor affecting the FEs. The FEs of N95 and surgical mask were better than those of single-use mask and cloth mask; 2) As particle size decreased, the FEs tended to reduce. The trend was significantly observed in FEs of aerosols with particle size < 1 μ m ; 3) After wearing N95 and surgical masks for 0, 2, 4, and 8 h, their FEs (%) maintained from 95.75 ± 0.09 to 100 ± 0 range. While a significant decrease in FEs were noticed for single-use masks worn for 8 h and cloth masks worn >2 h under deep breathing (30 L/min); 4) Both inward and outward FEs of N95 and surgical masks were similar, while the outward FEs of single-use and cloth masks were higher than their inward FEs; 5) The FEs under deep breathing was significantly lower than normal breathing with aerosol particle size <1 μ m. In conclusion, our results revealed that masks have a critical role in preventing the spread of aerosol particles by filtering inhalation, and FEs significantly decreased with the increasing of respiratory volume and wearing time. Deep breathing may cause increasing humidity and hence decrease FEs by increasing the airflow pressure. With the increase of wearing time, the adsorption capacity of the filter material tends to be saturated, which may reduce FEs. Findings may be used to provide information for policies regarding the proper use of masks for general public in current and future pandemics.

Coronavirus disease (COVID-19) transmission through aerosols in restorative and endodontic practice: Strategies for prevention

Rapid spread of coronavirus disease 2019 (COVID-19) in several countries of the world has created a state of public health emergency. COVID-19 is principally a respiratory disease, and the virus is present in respiratory secretions. Oral health-care professionals are susceptible to being infected with the disease since they work in close proximity to patient's face and oral cavity for long period of time. Restorative dentists and endodontists play a significant role in delivering "urgent" or "emergency" dental care to patients. Occupational Safety and Health Administration has categorized dentists performing aerosol-generating treatment procedures at "very high exposure risk" whereas the dentists not performing aerosol-generating procedures at "high exposure risk." Most of the restorative and endodontic treatment procedures involve generation of aerosols. Owing to the possibility of transmission of virus through aerosols, these procedures may transmit the disease to clinician or other patients. A comprehensive search of literature was conducted with the help of PubMed/MEDLINE and Scopus databases using a combination of terms, "COVID-19," "severe acute respiratory syndrome coronavirus 2," "aerosols," "restorative dentistry," and "endodontics." Along with universal precautions, some additional precautions need to be taken to prevent such transmission and cross-infection. This article reviews the research evidence about the role of aerosols in the transmission of COVID-19 and various measures which should be implemented during restorative and endodontic practice for the prevention of such transmission.

Front lines of the COVID-19 pandemic: what is the effectiveness of using personal protective equipment in health service environments?-a systematic review

PURPOSE

This systematic review aimed to evaluate the effectiveness of the use of personal protective equipment (PPE) in closed environments, similar to waiting or exam rooms of healthcare facilities, in the face of exposure to a bioaerosol.

METHODS

Combinations of words were selected for six electronic databases and for the gray literature. To consider the eligibility of the studies to be included/excluded, the acronym "PECOS" was used: humans and/or experimental models that simulate aerosol (Population); aerosol exposure and the use of masks/respirators (exposition/intervention); controlled or not controlled (comparison); effectiveness of PPE and the receiver exposure (outcomes); and randomized clinical studies or not, observational or laboratory simulation studies (Studies design).

RESULTS

A total of 4820 references were retrieved by the search strategy. Thirty-five articles were selected for complete reading, of which 13 articles were included for qualitative synthesis. A surgical mask or N95 respirator reduced the risk of transmission, even over short distances. The use of masks, even those with less filtering power, when used by all individuals in the same environment is more effective in reducing risk than the use of respirators with high filtering power for only some of the individuals present.

CONCLUSION

The use of mask in closed environments is effective in reducing the risk of transmission and contagion of a contaminated bioaerosol, with greater effectiveness when these devices are used by the source and receiver, regardless of the equipment's filtering power. (PROSPERO 2020 CRD 42020183759).

Physical therapists' knowledge and implementation of best practices in the outpatient physiotherapy department during the COVID-19 pandemic: A cross-sectional study

BACKGROUND

Physiotherapists (PTs) play an important role in the well-being and physical rehabilitation of patients with long term health problems. It is important that PTs follow recommended practices that minimize the transmission of SARS-CoV-2 infection in providing Outpatient Physiotherapy services.

OBJECTIVE

The aim of this study was to assess the knowledge of COVID-19 among the PTs and evaluate the state of implementation of best practices in Outpatient Physiotherapy to prevent SARS-CoV-2 infections during the ongoing pandemic.

METHODS

A self-administered online questionnaire consisting of three sections, including section one on demographic information, section two on evaluating knowledge about SARS-CoV-2 and section three on implementing best practices as a survey tool for collecting data from physiotherapist working in Lahore and Faisalabad in Punjab, Pakistan.

RESULTS

A total of 216 completed surveys were received. Correct responses to different questions devised to test the participants' knowledge of SARS-CoV-2 varied from 58.3% to 99% . The implementation of best practices to prevent the infection transmission in the Outpatient Physiotherapy ranged from 22.7% to 92.1% for different domains. The age of the PTs and OPD setting were associated significantly with the PTs' knowledge of COVID-19 and also with the state of implementation of recommended practices to prevent SARS-CoV-2 infections in the Outpatient Physiotherapy (p <  .05).

CONCLUSION

The majority of the PTs, particularly those working in the clinic setting, possessed a good knowledge of COVID-19 and implemented best practices in their Outpatient Physiotherapy at a good level. However, efforts should be directed towards further improving the knowledge of PTs and ensuring implementation of best practices in Outpatient Physiotherapy, particularly in government and private hospitals.

Provision of Endodontic Treatment in Dentistry amid COVID-19: A Systematic Review and Clinical Recommendations

Background

The risk of acquiring COVID-19 during a pandemic is a major concern among health care workers. Dental professionals being in close proximity to the patients had been exposed more than other health care workers. Hence, all the standard operating procedures (SOPs) are strictly advised to be followed.

Methods

A detailed relevant literature search was conducted in international databases such as PubMed, Web of Science, and Science Direct, from January 2020 to November 2020. All the studies that provided recommendations regarding endodontic procedures during the COVID-19 pandemic were included, and those that were not in the English language, case reports, book chapters, and short communications were excluded in this review. In the end, only 6 articles were selected for the systematic review considering that complete information regarding the provision of dental care in the time of COVID-19 with diagnostic accuracy (STARD) was provided.

Results

Endodontic treatments were restricted to only emergency dental procedures, and all other patients have advised medications and catered through teledentistry. Endodontic emergencies were advised to be carried out with minimal aerosol production procedures.

Conclusion

Provision of endodontic care during COVID-19 restricted to only emergency dental procedures by strictly following standard operating procedures. A protocol for COVID-19 prevention was followed by all the dentists and the dental staff in the dental clinics.

The Impact of Ubiquitous Face Masks and Filtering Face Piece Application During Rest, Work and Exercise on Gas Exchange, Pulmonary Function and Physical Performance: A Systematic Review with Meta-analysis

BACKGROUND

Protection against airborne infection is currently, due to the COVID-19-associated restrictions, ubiquitously applied during public transport use, work and leisure time. Increased carbon dioxide re-inhalation and breathing resistance may result thereof and, in turn, may negatively impact metabolism and performance.

OBJECTIVES

To deduce the impact of the surgical mask and filtering face piece type 2 (FFP2) or N95 respirator application on gas exchange (pulse-derived oxygen saturation (SpO₂), carbon dioxide partial pressure (PCO₂), carbon dioxide exhalation (VCO₂) and oxygen uptake (VO₂)), pulmonary function (respiratory rate and ventilation) and physical performance (heart rate HR, peak power output W_peak).

METHODS

Systematic review with meta-analysis. Literature available in Medline/Pubmed, the Cochrane Library and the Web of Knowledge with the last search on the 6^th of May 2021. Eligibility criteria: Randomised controlled parallel group or crossover trials (RCT), full-text availability, comparison of the acute effects of ≥ 1 intervention (surgical mask or FFP2/N95 application) to a control/comparator condition (i.e. no mask wearing). Participants were required to be healthy humans and > 16 years of age without conditions or illnesses influencing pulmonary function or metabolism. Risk of bias was rated using the crossover extension of the Cochrane risk of bias assessment tool II. Standardised mean differences (SMD, Hedges' g) with 95% confidence intervals (CI) were calculated, overall and for subgroups based on mask and exercise type, as pooled effect size estimators in our random-effects meta-analysis.

RESULTS

Of the 1499 records retrieved, 14 RCTs (all crossover trials, high risk of bias) with 25 independent intervention arms (effect sizes per outcome) on 246 participants were included. Masks led to a decrease in SpO₂ during vigorous intensity exercise (6 effect sizes; SMD = - 0.40 [95% CI: - 0.70, - 0.09], mostly attributed to FFP2/N95) and to a SpO₂-increase during rest (5 effect sizes; SMD = 0.34 [95% CI: 0.04, 0.64]); no general effect of mask wearing on SpO₂ occurred (21 effect sizes, SMD = 0.34 [95% CI: 0.04, 0.64]). Wearing a mask led to a general oxygen uptake decrease (5 effect sizes, SMD = - 0.44 [95% CI: - 0.75, - 0.14]), to slower respiratory rates (15 effect sizes, SMD = - 0.25 [95% CI: - 0.44, - 0.06]) and to a decreased ventilation (11 effect sizes, SMD = - 0.43 [95% CI: - 0.74, - 0.12]). Heart rate (25 effect sizes; SMD = 0.05 [95% CI: - 0.09, 0.19]), W_peak (9 effect sizes; SMD = - 0.12 [95% CI: - 0.39, 0.15]), PCO₂ (11 effect sizes; SMD = 0.07 [95% CI: - 0.14, 0.29]) and VCO₂ (4 effect sizes, SMD = - 0.30 [95% CI: - 0.71, 0.10]) were not different to the control, either in total or dependent on mask type or physical activity status.

CONCLUSION

The number of crossover-RCT studies was low and the designs displayed a high risk of bias. The within-mask- and -intensity-homogeneous effects on gas exchange kinetics indicated larger detrimental effects during exhausting physical activities. Pulse-derived oxygen saturation was increased during rest when a mask was applied, whereas wearing a mask during exhausting exercise led to decreased oxygen saturation. Breathing frequency and ventilation adaptations were not related to exercise intensity. FFP2/N95 and, to a lesser extent, surgical mask application negatively impacted the capacity for gas exchange and pulmonary function but not the peak physical performance. Registration: Prospero registration number: CRD42021244634.