The use of masks and respirators to prevent transmission of influenza: a systematic review of the scientific evidence

Cost-effectiveness of mask mandates on subways to prevent SARS-CoV-2 transmission in the United States

BACKGROUND

Community-based mask wearing has been shown to reduce the transmission of SARS-CoV-2. However, few studies have conducted an economic evaluation of mask mandates, specifically in public transportation settings. This study evaluated the cost-effectiveness of implementing mask mandates for subway passengers in the United States by evaluating its potential to reduce COVID-19 transmission during subway travel.

MATERIALS AND METHODS

We assessed the health impacts and costs of subway mask mandates compared to mask recommendations based on the number of infections that would occur during subway travel in the U.S. Using a combined box and Wells-Riley infection model, we estimated monthly infections, hospitalizations, and deaths averted under a mask mandate scenario as compared to a mask recommendation scenario. The analysis included costs of implementing mask mandates and COVID-19 treatment from a limited societal perspective. The cost-effectiveness (net cost per averted death) of mandates was estimated for three different periods based on dominant SARS-CoV-2 variants: Alpha, Beta, and Gamma (November 2020 to February 2021); Delta (July to October 2021); and early Omicron (January to March 2022).

RESULTS

Compared with mask recommendations only, mask mandates were cost-effective across all periods, with costs per averted death less than a threshold of $11.4 million (ranging from cost-saving to $3 million per averted death). Additionally, mask mandates were more cost-effective during the early Omicron period than the other two periods and were cost saving in January 2022. Our findings showed that mandates remained cost-effective when accounting for uncertainties in input parameters (e.g., even if mandates only resulted in small increases in mask usage by subway ridership).

CONCLUSIONS

The findings highlight the economic value of mask mandates on subways, particularly during high virus transmissibility periods, during the COVID-19 pandemic. This study may inform stakeholders on mask mandate decisions during future outbreaks of novel viral respiratory diseases.

Narrative review on century of respiratory pandemics from Spanish flu to COVID-19 and impact of nanotechnology on COVID-19 diagnosis and immune system boosting

The rise of the highly lethal severe acute respiratory syndrome-2 (SARS-2) as corona virus 2019 (COVID-19) reminded us of the history of other pandemics that happened in the last century (Spanish flu) and stayed in the current century, which include Severe-Acute-Respiratory-Syndrome (SARS), Middle-East-Respiratory-Syndrome (MERS), Corona Virus 2019 (COVID-19). We review in this report the newest findings and data on the origin of pandemic respiratory viral diseases, reservoirs, and transmission modes. We analyzed viral adaption needed for host switch and determinants of pathogenicity, causative factors of pandemic viruses, and symptoms and clinical manifestations. After that, we concluded the host factors associated with pandemics morbidity and mortality (immune responses and immunopathology, ages, and effect of pandemics on pregnancy). Additionally, we focused on the burdens of COVID-19, non-pharmaceutical interventions (quarantine, mass gatherings, facemasks, and hygiene), and medical interventions (antiviral therapies and vaccines). Finally, we investigated the nanotechnology between COVID-19 analysis and immune system boosting (Nanoparticles (NPs), antimicrobial NPs as antivirals and immune cytokines). This review presents insights about using nanomaterials to treat COVID-19, improve the bioavailability of the abused drugs, diminish their toxicity, and improve their performance.

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.

Reusable respirators as personal protective equipment in clinical practice : User experience in times of a pandemic

Background

The novel strain of severe acute respiratory syndrome coronavirus 2 is highly contagious; therefore, special emphasis must be given to personal protective equipment for healthcare workers. Reusable elastomeric respirators were previously used in intensive care units (ICU). These respirators include full or half masks and devices modified to accommodate a filter. Although the general comfort of masks used in the ICU has been studied, data comparing multiple types of masks during a pandemic are missing.

Methods

A prospective randomized trial was conducted in an ICU. After standardized training, participants were randomized to use one of three mask types (full, half or snorkelling mask), each fitted with a filter equivalent to a class 3 particle-filtering half mask (FFP3) during one shift. The main outcomes were characteristics of using the mask itself (donning/doffing, quality of seal, cleaning), working conditions with the mask (vision, comfort, perceived safety, communication) and a subjective comparison to single-use FFP2/3 masks.

Results

A total of 30 participants were included in the trial, randomized to 10 participants per group. The masks were worn 6.4 (4.5) times (mean SD) for a total duration of 132 (66) min per shift. The tested masks were rated 7 (2.6) (mean SD) in comparison to FFP2/3 on a Likert scale (0: worst, 10: best). Significant differences between the masks were found in respect to comfort (7/4/8), donning (8/7/9), overall rating (8/5/8) and comparison to single-use FFP2/3 masks (9/7/9; full-, half, snorkelling mask).

Conclusion

Using reusable elastomeric masks is feasible in clinical practice. Full face masks were significantly better in terms of comfort, donning, overall rating and in comparison to single-use FFP2/3 masks.

Did Hospital Admissions Caused by Respiratory Infections and Asthma Decrease During the COVID-19 Pandemic?

Objective

Despite maximum isolation measures taken during the coronavirus disease-2019 (COVID-19) pandemic, the workload of health institutions has increased. Consequently, changes in the number of admissions in clinics and emergency departments by disease groups have been observed. We aimed to quantitatively investigate the changes in the frequency of respiratory infections and asthma in the pediatric population during the COVID-19 pandemic.

Methods

We analyzed electronic medical record data of patients who were admitted to the emergency department (ED), outpatient and inpatient clinics, and pediatric intensive care unit (PICU) because of influenza, upper and lower respiratory tract infections (URTI, LRTI), acute bronchiolitis, and asthma during the two-year period (one year pre-COVID period and first year of the pandemic).

Results

There were 96,648 admissions in the pre-COVID period and 15,848 during the pandemic. We observed a decline in ED admissions (-73%), outpatient clinic visits (-70%), hospitalizations (-41.5%), and PICU admissions (-42%). While the admission rates of patients with influenza [from 4.26% to 0.37% (p=0.0001)] and URTI [from 81.54% to 75.62% (p=0.0001)] decreased, the ratio of the number of admissions to the total number of admissions due to LRTI [from 8.22% to 10.01% (p=0.0001)], acute bronchiolitis [from 2.76% to 3.07% (p=0.027)], and asthma [from 5.96% to 14% (p=0.0001)] increased.

Conclusions

The decrease in viruses that cause acute bronchiolitis and asthma attacks lead to a reduction in admissions to ED of this patient group. The fact that parents preferred not to admit their child in ED during this period may have paved the way for the development of more severe LRTIs.

Effectiveness of Mask-Wearing on Respiratory Illness Transmission in Community Settings: A Rapid Review

OBJECTIVE

Respiratory illnesses, including coronavirus disease 2019 (COVID-19), have resulted in millions of deaths globally. Guidance on mask-wearing in community settings has been inconsistent. This review examined the effectiveness of mask-wearing on respiratory virus transmission in community settings.

METHODS

A search was conducted for English language reports of randomized controlled trials of mask-wearing in the community and effect on laboratory-confirmed respiratory infections or influenza-like illness. Investigators abstracted study characteristics and assessed bias. Meta-analysis was conducted to calculate pooled risk estimates.

RESULTS

Eleven studies were included. In 7 studies that evaluated influenza-like illness symptoms as an outcome (3029 participants), this study found mask-wearing associated with a decreased risk of influenza-like illness (overall risk ratio [RR], 0.83; 95% confidence interval [CI], 0.71 to 0.96). Studies examining laboratory-confirmed respiratory infections as an outcome (10,531 participants) showed no statistically significant association between mask-wearing and infections (RR, 1.04; 95% CI, 0.60-1.80). However, masking combined with enhanced hand hygiene was associated with a decreased risk for both influenza-like illness symptoms (RR, 0.88; 95% CI, 0.51-1.51) and laboratory-confirmed respiratory infection (RR, 0.79; 95% CI, 0.52-1.18).

CONCLUSIONS

Masking in community settings decreases transmission of influenza-like illness. Mask-wearing combined with enhanced hand hygiene reduces transmission of influenza-like illness and laboratory-confirmed respiratory infection.

Effect of a multimodal strategy for prevention of nosocomial influenza: a retrospective study at Grenoble Alpes University Hospital from 2014 to 2019

Background

A multimodal strategy to prevent nosocomial influenza was implemented in 2015–2016 in Grenoble Alpes University Hospital. Three modalities were implemented in all units: promotion of vaccination among healthcare workers, epidemiologic surveillance and communication campaigns. Units receiving a high number of patients with influenza implemented 2 additional modalities: improvement of diagnosis capacities and systematic surgical mask use. The main objective was to assess the effectiveness of the strategy for reducing the risk of nosocomial influenza.

Methods

A study was conducted retrospectively investigating 5 epidemic seasons (2014–2015 to 2018–2019) including all patients hospitalized with a positive influenza test at Grenoble Alpes University Hospital. The weekly number of nosocomial influenza cases was analyzed by Poisson regression and incidence rate ratios (IRR) were estimated.

Results

A total of 1540 patients, resulting in 1559 stays, were included. There was no significant difference between the 5 influenza epidemic seasons in the units implementing only 3 measures. In the units implementing the 5 measures, there was a reduction of nosocomial influenza over the seasons when the strategy was implemented compared to the 2014–2015 epidemic season (IRR = 0.56, 95% CI = 0.23–1.34 in 2015–2016; IRR = 0.39, 95% CI = 0.19–0.81 in 2016–2017; IRR = 0.50, 95% CI = 0.24–1.03 in 2017–2018; IRR = 0.48, 95% CI = 0.23–0.97 in 2018–2019).

Conclusions

Our data mainly suggested that the application of the strategy with 5 modalities, including systematic surgical mask use and rapid diagnosis, seemed to reduce by half the risk of nosocomial influenza. Further data, including medico-economic studies, are necessary to determine the opportunity of extending these measures at a larger scale.

Economic burden of public health care and hospitalisation associated with COVID-19 in China

OBJECTIVES

This study aimed to evaluate the socio-economic burden imposed on the Chinese healthcare system during the coronavirus disease 2019 (COVID-19) pandemic.

STUDY DESIGN

A cross-sectional study was used to investigate how COVID-19 impacted health and medical costs in China. Data were derived from a subdivision of the Centers for Disease control and Prevention of China.

METHODS

We prospectively collected information from the Centers for Disease Control and Prevention and the designated hospitals to determine the cost of public health care and hospitalisation due to COVID-19. We estimated the resource use and direct medical costs associated with public health.

RESULTS

The average costs, per case, for specimen collection and nucleic acid testing (NAT [specifically, polymerase chain reaction {PCR}]) in low-risk populations were $29.49 and $53.44, respectively; however, the average cost of NAT in high-risk populations was $297.94 per capita. The average costs per 1000 population for epidemiological surveys, disinfectant, health education and centralised isolation were $49.54, $247.01, $90.22 and $543.72, respectively. A single hospitalisation for COVID-19 in China cost a median of $2158.06 ($1961.13-$2325.65) in direct medical costs incurred only during hospitalisation, whereas the total costs associated with hospitalisation of patients with COVID-19 were estimated to have reached nearly $373.20 million in China as of 20, May, 2020. The cost of public health care associated with COVID-19 as of 20, May, 2020 ($6.83 billion) was 18.31 times that of hospitalisation.

CONCLUSIONS

This study highlights the magnitude of resources needed to treat patients with COVID-19 and control the COVID-19 pandemic. Public health measures implemented by the Chinese government have been valuable in reducing the infection rate and may be cost-effective ways to control emerging infectious diseases.

Interventions on Socioeconomic and Racial Inequities in Respiratory Pandemics: a Rapid Systematic Review

Purpose of Review

Racial and socioeconomic inequities in respiratory pandemics have been consistently documented, but little official guidance exists on effective action to prevent these. We systematically reviewed quantitative evaluations of (real or simulated) interventions targeting racial and socioeconomic inequities in respiratory pandemic outcomes.

Recent Findings

Our systematic search returned 10,208 records, of which 5 met inclusion criteria, including observational (n = 1), randomized trial (n = 1), and simulation (n = 3) studies. Interventions studied included vaccination parity, antiviral distribution, school closure, disinfection, personal protective equipment, and paid sick leave, with a focus on Black (n = 3) and/or Latinx (n = 4) or low-SES (n = 2) communities. Results are suggestive that these interventions might be effective at reducing racial and/or SES disparities in pandemics.

Summary

There is a dearth of research on strategies to reduce pandemic disparities. We provide theory-driven, concrete suggestions for incorporating equity into intervention research for pandemic preparedness, including a focus on social and economic policies.

Anxiety and Perceived Risk in Red Cross Volunteer Personnel Facing the Coronavirus Disease 2019 Pandemic

In the current situation of sanitary emergencies, humanitarian organizations and their volunteers are playing an important role in the coronavirus disease 2019 (COVID-19) pandemic. A study is proposed that includes a network of volunteers who perform humanitarian activities during the COVID-19 pandemic to assess anxiety, perceived risk, and response behaviors and to explore their relationship with sociodemographic variables. For data collection, an online questionnaire was developed through the Google Forms® platform, where the perceived risk, anxiety, and behavioral responses of the general population to the Influenza A (H1N1) pandemic were assessed. The survey presented is a modified version of that survey adapted for COVID-19. This adaptation was endorsed by an experts committee made up of the health chief of the Ecuadorian Red Cross, the focus point of operations from the International Federation of the Red Cross in Ecuador, and a member from the Health Unit of the Americas Regional Office of the International Federation of the Red Cross. A significant relationship has been shown between the job situation and perceived risk and anxiety, being the staff who worked full time away from home, which was exposed to greater risk and anxiety. Both perceived risk and perceived anxiety are very high (according to a 5-point Likert scale). Knowing these data from this first-line personnel will allow adopting measures that could be beneficial for stress management and, therefore, contribute to the well-being and support of these humanitarian and volunteer organizations in the worldwide response to COVID-1 9.

Unmasking the mask studies: why the effectiveness of surgical masks in preventing respiratory infections has been underestimated

BACKGROUND

Pre-pandemic empirical studies have produced mixed statistical results on the effectiveness of masks against respiratory viruses, leading to confusion that may have contributed to organizations such as the WHO and CDC initially not recommending that the general public wear masks during the coronavirus disease 2019 pandemic.

METHODS

A threshold-based dose-response curve framework is used to analyse the effects of interventions on infection probabilities for both single and repeated exposure events. Empirical studies on mask effectiveness are evaluated with a statistical power analysis that includes the effect of adherence to mask usage protocols.

RESULTS

When the adherence to mask usage guidelines is taken into account, the empirical evidence indicates that masks prevent disease transmission: all studies we analysed that did not find surgical masks to be effective were under-powered to such an extent that even if masks were 100% effective, the studies in question would still have been unlikely to find a statistically significant effect. We also provide a framework for understanding the effect of masks on the probability of infection for single and repeated exposures. The framework demonstrates that masks can have a disproportionately large protective effect and that more frequently wearing a mask provides super-linearly compounding protection.

CONCLUSIONS

This work shows (1) that both theoretical and empirical evidence is consistent with masks protecting against respiratory infections and (2) that non-linear effects and statistical considerations regarding the percentage of exposures for which masks are worn must be taken into account when designing empirical studies and interpreting their results.

Preventive effects of tea and tea catechins against influenza and acute upper respiratory tract infections: a systematic review and meta-analysis

Purpose

Gargling with tea has protective effects against influenza infection and upper respiratory tract infection (URTI). To evaluate if tea and tea catechin consumption has the same protective effects as gargling with tea, we performed a systematic review and meta-analysis.

Methods

We performed a comprehensive literature search using the PubMed, Cochrane Library, Web of Science, and Ichu-shi Web databases. The search provided six randomized controlled trials (RCTs) and four prospective cohort studies (n = 3748). The quality of each trial or study was evaluated according to the Cochrane risk-of-bias tool or Newcastle–Ottawa Scale. We collected data from publications meeting the search criteria and conducted a meta-analysis of the effect of tea gargling and tea catechin consumption for preventing URTI using a random effects model.

Results

Tea gargling and tea catechin consumption had significant preventive effects against URTI (risk ratio [RR] = 0.74, 95% confidence interval [CI] 0.64–0.87). In sub-analyses, a significant preventive effect was observed by study type (prospective cohort study: RR = 0.67, 95% CI 0.50–0.91; RCT: RR = 0.79, 95% CI 0.66–0.94) and disease type (influenza: RR = 0.69, 95% CI 0.58–0.84; acute URTI: RR = 0.78, 95% CI 0.62–0.98). Both gargling with tea and consuming tea catechins effectively protected against URTI (tea and tea catechins consumption: RR = 0.68, 95% CI 0.52–0.87; tea gargling: RR = 0.83, 95% CI 0.72–0.96).

Conclusion

Our findings suggest that tea gargling and tea catechin consumption may have preventive effects against influenza infection and URTI. The potential effectiveness of these actions as non-pharmaceutical interventions, however, requires further investigation.

Effect of N95 filtering facepiece respirators on dental health professionals with an emphasis on pulmonary function and heart rate: An intrasubject comparison

Despite the ubiquitous use of N95 filtering facepiece respirators (N95 FFR), published literature on the topic remains scarce, especially in relation to dental professionals. This study assesses the impact of N95 FFRs on blood oxygen saturation and heart rate of dental health professionals while performing procedures requiring varying degrees of physical exertion in an aerosol-rich environment. A total of 51 participants, consisting of 43 men and eight women aged between 23 and 31 years were recruited into the study. All subjects were well-versed in wearing personal protective equipment (PPE). A clinical grade pulse oximeter was used with a clamp placed around the fingertip or the earlobe of the participant. The selection of N95 FFR was based on fit and leakage. All data were collected once from the same participants using a surgical mask as a control. Data were collected again from the same subjects after 1, 2, and 3 hours of use. There were significant differences in both oxygen saturation (SpO₂) and heart rate between the two groups after 1, 2, and 3 hours of wearing the respective masks. In healthy young individuals, wearing an N95 FFR for an extended period of time during clinical dental procedures reduced the SpO₂level and increased the heart rate compared with a standard surgical mask. However, SpO₂ levels remained within a healthy range of more than 95%, and heart rate was within acceptable limits.

Practices and Perceptions of Face Mask Use in a Pediatric Health System During the COVID-19 Pandemic

BACKGROUND

Face coverings are recommended to help mitigate the spread of COVID-19. Guidelines regarding face mask use have evolved from the time when COVID-19 first emerged. Practices for face mask use in the United States vary widely.

METHODS

Clinical and nonclinical staff from a pediatric health care system were invited to complete a survey regarding perceptions and practices of face mask use during the COVID-19 pandemic. Overall results were analyzed, and subgroup analyses were conducted to compare clinical and nonclinical staff, and clinical staff who do and do not provide direct patient care.

RESULTS

The response rate was approximately 24% (1,128 of 4,698). Most respondents were clinical staff who provide patient care. A surgical/procedure mask was most often worn for patient care by 72% (P < .001). Most respondents (70%) reported wearing a cloth mask when not in the hospital (P < .001). Cloth masks were worn for a mean of 3.4 ± 3.9 d before washing. Frequent hand hygiene before putting on the mask, before removing, and after removing was reported as 56%, 44%, and 62%, respectively. The most common challenges reported were glasses fogging (69%), skin irritations (45%), and headaches (31%). Qualitative data revealed themes of feeling unsafe, beliefs and practices about COVID-19 and masks, mandates and enforcement of wearing masks, availability of personal protective equipment, and care delivery challenges.

CONCLUSIONS

Practices and perceptions of face masks varied among staff in a pediatric health care system. Some staff did not feel that masks are effective in preventing virus spread, and others did not feel safe in performing job duties. Hand hygiene for mask handling was not practiced consistently. A large number of staff reported having experienced challenges or health issues when wearing a mask. Clinical staff who provide direct patient care reported more issues than both nonclinical and clinical staff who do not provide care.

Combined Effects of Masking and Distance on Aerosol Exposure Potential

OBJECTIVE

To quantify the efficacy of masking and "social distancing" on the transmission of airborne particles from a phantom aerosol source (simulating an infected individual) to a nearby target (simulating a healthy bystander) in a well-controlled setting.

METHODS

An aerosol was created using monodisperse polystyrene latex beads in place of infectious respiratory secretions. Detection was by aerodynamic particle spectrometry. Both reusable cloth masks and disposable paper masks were studied. Transmission was simulated indoors during a 3-minute interval to eliminate the effect of variable ventilation rate on aerosol exposure. The study commenced on September 16, 2020, and concluded on December 15, 2020.

RESULTS

Compared with a baseline of 1-foot separation with no masks employed, particle count was reduced by 84% at 3 feet of separation and 97% at 6 feet. A modest decrease in particle count was observed when only the receiver was masked. The most substantial exposure reduction occurred when the aerosol source was masked (or both parties were masked). When both the source and target were masked, particle count was reduced by more than 99.5% of baseline, regardless of separation distance or which type of mask was employed.

CONCLUSION

These results support the principle of layered protection to mitigate transmission of SARS-CoV-2, the virus causing COVID-19, and other respiratory viruses and emphasize the importance of controlling the spread of aerosol at its source. The combination of masking and distancing reduced the exposure to exhaled particulates more than any individual measure. Combined measures remain the most effective way to combat the spread of respiratory infection.

Anti-Influenza with Green Tea Catechins: A Systematic Review and Meta-Analysis

Influenza is one of the most serious respiratory viral infections worldwide. Although several studies have reported that green tea catechins (GTCs) might prevent influenza virus infection, this remains controversial. We performed a systematic review and meta-analysis of eight studies with 5048 participants that examined the effect of GTC administration on influenza prevention. In a random-effects meta-analysis of five RCTs, 884 participants treated with GTCs showed statistically significant effects on the prevention of influenza infection compared to the control group (risk ratio (RR) 0.67, 95% CIs 0.51–0.89, p = 0.005) without evidence of heterogeneity (I² = 0%, p = 0.629). Similarly, in three cohort studies with 2223 participants treated with GTCs, there were also statistically significant effects (RR 0.52, 95% CIs 0.35–0.77, p = 0.001) with very low evidence of heterogeneity (I² = 3%, p = 0.358). Additionally, the overall effect in the subgroup analysis of gargling and orally ingested items (taking capsules and drinking) showed a pooled RR of 0.62 (95% CIs 0.49–0.77, p = 0.003) without heterogeneity (I² = 0%, p = 0.554). There were no obvious publication biases (Egger’s test (p = 0.138) and Begg’s test (p = 0.103)). Our analysis suggests that green tea consumption is effective in the prophylaxis of influenza infections. To confirm the findings before implementation, longitudinal clinical trials with specific doses of green tea consumption are warranted.

Effects of the filter microstructure and ambient air condition on the aerodynamic dispersion of sneezing droplets: A multiscale and multiphysics simulation study

Concerns have been ramping up with regard to the propagation of infectious droplets due to the recent COVID-19 pandemic. The effects of filter microstructures and ambient air flows on droplet dispersion by sneezing are investigated by a fully coupled Eulerian-Lagrangian computational modeling with a micro-to-macroscale bridging approach. Materials that are commonly applied to face masks are modeled to generate two different virtual masks with various levels of filtration efficiency, and the leakage percentages through the unsealed nose and cheek areas were set to 11% and 25%, respectively. The droplet propagation distance was simulated with and without mask wearing in still and windy conditions involving head wind, tail wind, and side wind. The results demonstrate that wearing a face mask reduces the transmittance distance of droplets by about 90%-95% depending on the mask type; nonetheless, the droplets can be transmitted to distances of 20-25 cm in the forward direction even with mask-wearing. Thus, a social distance of at least 20 cm between people would help to prevent them from becoming exposed to ejected droplets. This study is significant in that important aspects of mask materials, in this case the porous microstructure-dependent filtration efficiency and permeability under varied ambient flow conditions, were considered for the first time in an evaluation of the barrier performance against droplet transmittance through a multiphase computational fluid dynamics simulation of air-droplet interaction and turbulence flow dynamics.

Face masks against COVID-19: Standards, efficacy, testing and decontamination methods

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus responsible for the novel coronavirus disease 2019 (COVID-19), has caused a global pandemic on a scale not seen for over a century. Increasing evidence suggests that respiratory droplets and aerosols are likely the most common route of transmission for SARS-CoV-2. Since the virus can be spread by presymptomatic and asymptomatic individuals, universal face masking has been recommended as a straightforward and low-cost strategy to mitigate virus transmission. Numerous governments and public health agencies around the world have advocated for or mandated the wearing of masks in public settings, especially in situations where social distancing is not possible. However, the efficacy of wearing a mask remains controversial. This interdisciplinary review summarizes the current, state-of-the-art understanding of mask usage against COVID-19. It covers three main aspects of mask usage amid the pandemic: quality standards for various face masks and their fundamental filtration mechanisms, empirical methods for quantitatively determining mask integrity and particle filtration efficiency, and decontamination methods that allow for the reuse of traditionally disposable N95 and surgical masks. The focus is given to the fundamental physicochemical and engineering sciences behind each aspect covered in this review, providing novel insights into the current understanding of mask usage to curb COVID-19 spread.

Aerosolised fluorescein can quantify FFP mask faceseal leakage: a cost-effective adaptation to the existing point of care fit test

BACKGROUND

A qualitative fit test using bitter-tasting aerosols is the commonest way to determine filtering face-piece (FFP) mask leakage. This taste test is subjective and biased by placebo. We propose a cheap, quantitative modification of the taste test by measuring the amount of fluorescein stained filter paper behind the mask using image analysis.

METHODS

A bitter-tasting fluorescein solution was aerosolised during mask fit tests, with filter paper placed on masks' inner surfaces. Participants reported whether they could taste bitterness to determine taste test 'pass' or 'fail' results. Filter paper photographs were digitally analysed to quantify total fluorescence (TF).

RESULTS

Fifty-six healthcare professionals were fit tested; 32 (57%) 'passed' the taste test. TF between the taste test 'pass' and 'fail' groups was significantly different (p<0.001). A cut-off (TF = 5.0 × 10⁶ units) was determined at precision (78%) and recall (84%), resulting in 5/56 participants (9%) reclassified from 'pass' to 'fail' by the fluorescein test. Seven out of 56 (12%) reclassified from 'fail' to 'pass'.

CONCLUSION

Fluorescein is detectable and sensitive at identifying FFP mask leaks. These low-cost adaptations can enhance exiting fit testing to determine 'pass' and 'fail' groups, protecting those who 'passed' the taste test but have high fluorescein leak, and reassuring those who 'failed' the taste test despite having little fluorescein leak.

Wearing masks to reduce the spread of respiratory viruses: a systematic evidence mapping

Since the outbreak of coronavirus disease in 2019, the controversy over the effectiveness, safety, and enforceability of masks used by the public has been prominent. This study aims to identify, describe, and organize the currently available high-quality design evidence concerning mask use during the spread of respiratory viruses and find evidence gaps. Databases including PubMed, Cochrane Library, Web of Science, EMBASE, WHO International Clinical Trials Registry Platform (ICTRP), clinical trial registry, gray literature database, and reference lists of articles were searched for relevant randomized controlled trials (RCTs) and systematic reviews (SRs) in April 2020. The quality of the studies was assessed using the risk of bias tool recommended by the Cochrane Handbook Version 5.1.0 and the Assessment of Multiple Systematic Reviews (AMSTAR 2) tool. A bubble plot was designed to display information in four dimensions. Finally, twenty-one RCTs and nine SRs met our inclusion criteria. Most studies were of "Low quality" and focused on healthcare workers. Six RCTs reported adverse effects, with one implying that the cloth masks reuse may increase the infection risk. When comparing masks with usual practice, over 70% RCTs and also SRs showed that masks were "beneficial" or "probably beneficial"; however, when comparing N95 respirators with medical masks, 75% of SRs showed "no effect", whereas 50% of RCTs showed "beneficial effect". Overall, the current evidence provided by high-quality designs may be insufficient to deal with a second impact of the pandemic. Masks may be effective in interrupting or reducing the spread of respiratory viruses; however, the effect of an N95 respirator or cloth masks versus medical masks is unclear. Additional high-quality studies determining the impact of prolonged mask use on vulnerable populations (such as children and pregnant women), the possible adverse effects (such as skin allergies and shortness of breath) and optimal settings and exposure circumstances for populations to use masks are needed.

Modelling the potential impact of mask use in schools and society on COVID-19 control in the UK

As the UK reopened after the first wave of the COVID-19 epidemic, crucial questions emerged around the role for ongoing interventions, including test-trace-isolate (TTI) strategies and mandatory masks. Here we assess the importance of masks in secondary schools by evaluating their impact over September 1-October 23, 2020. We show that, assuming TTI levels from August 2020 and no fundamental changes in the virus's transmissibility, adoption of masks in secondary schools would have reduced the predicted size of a second wave, but preventing it would have required 68% or 46% of those with symptoms to seek testing (assuming masks' effective coverage 15% or 30% respectively). With masks in community settings but not secondary schools, the required testing rates increase to 76% and 57%.

Nonpharmacological interventions to reduce respiratory viral transmission: an evidence-based review with recommendations

BACKGROUND

Viral respiratory infections are a leading cause of worldwide mortality and exert the potential to cause global socioeconomic crises. However, inexpensive, efficacious, and rapidly deployable strategies to reduce viral transmission are increasingly important in the setting of an ongoing pandemic, though not entirely understood. This article provides a comprehensive review of commonly employed nonpharmacological interventions to interrupt viral spread and provides evidence-based recommendations for their use.

METHODOLOGY

A systematic review of three databases was performed. Studies with defined endpoints of subjects receiving one of five interventions (nasal washing, gargling, personal protective equipment (PPE), social distancing, and hand hygiene) were included. An evidence-based review of the highest level of evidence, with recommendations, was created in accordance with a previously described, rigorous, iterative process.

RESULTS

Fifty-four primary studies were included. The most commonly studied intervention was hand hygiene, followed by PPE, gargling, saline nasal washing, and social distancing.

CONCLUSIONS

Mask use and hand hygiene are strong recommendations for prevention of viral transmission. Donning gloves, gowns, and eye protection are a recommendation in healthcare settings. Saline nasal washing and gargling are options in selected populations. Although an aggregate level of evidence is not provided, the authors recommend social distancing.

Changes in respiratory diseases in Chongqing Health Center for women and children during COVID-19

By comparing the outpatient volume of paediatric patients and the outpatient volume of respiratory tract infections in Chongqing Health Center for Women and Children in China from 2017 to June 2020, the changes in the outpatient volume of paediatric patients and the outpatient volume of respiratory tract infections during coronavirus disease 2019 (COVID-19) were summarized and analysed to provide a basis for disease prevention.

Community use of face masks and similar barriers to prevent respiratory illness such as COVID-19: a rapid scoping review

BackgroundEvidence for face-mask wearing in the community to protect against respiratory disease is unclear.AimTo assess effectiveness of wearing face masks in the community to prevent respiratory disease, and recommend improvements to this evidence base.MethodsWe systematically searched Scopus, Embase and MEDLINE for studies evaluating respiratory disease incidence after face-mask wearing (or not). Narrative synthesis and random-effects meta-analysis of attack rates for primary and secondary prevention were performed, subgrouped by design, setting, face barrier type, and who wore the mask. Preferred outcome was influenza-like illness. Grading of Recommendations, Assessment, Development and Evaluations (GRADE) quality assessment was undertaken and evidence base deficits described.Results33 studies (12 randomised control trials (RCTs)) were included. Mask wearing reduced primary infection by 6% (odds ratio (OR): 0.94; 95% CI: 0.75-1.19 for RCTs) to 61% (OR: 0.85; 95% CI: 0.32-2.27; OR: 0.39; 95% CI: 0.18-0.84 and OR: 0.61; 95% CI: 0.45-0.85 for cohort, case-control and cross-sectional studies respectively). RCTs suggested lowest secondary attack rates when both well and ill household members wore masks (OR: 0.81; 95% CI: 0.48-1.37). While RCTs might underestimate effects due to poor compliance and controls wearing masks, observational studies likely overestimate effects, as mask wearing might be associated with other risk-averse behaviours. GRADE was low or very low quality.ConclusionWearing face masks may reduce primary respiratory infection risk, probably by 6-15%. It is important to balance evidence from RCTs and observational studies when their conclusions widely differ and both are at risk of significant bias. COVID-19-specific studies are required.

Efficacy of Generalized Face Masking Mandates

This commentary discusses if targeted uses of face masks may provide better results than generalized face masks mandates to limit the spread of Covid-19. The study is based on a literature review, as well as the analysis of cases and fatalities of different countries adopting different mask mandates. Before the Covid-19 emergency, the literature was consistently against generalized masking for cold and flu viruses. The latest literature for Covid-19 infection is opposite mostly supportive for generalized masking, even if contrarian works exist. The Covid-19 recommendations are not based on randomized controlled trials of healthy individuals wearing or not masks, differentiating in between closed or open spaces. Countries that did not mandate face masks have not performed worse for the number of cases and fatalities than countries that adopted generalized face masking policies during the Covid-19 emergency. Face masks help against Covid-19 infection but also have downfalls. Their benefits are overestimated, while their risks are underestimated. Masks can block the larger droplets exhaled by an infected wearer, protecting the healthy from viral exposure, but their ability to filter out viruses is variable and generally poor especially in reused cloth masks worn by the public. New surgical masks should be used in crowded spaces especially indoors, preferring distancing without masks outdoor. There are serious unintended consequences from wearing face masks improperly and for too long that must be accounted for. There could be more advantages from targeted rather than generalized uses of only surgical face masks.

Use of face masks and other personal preventive measures by Hajj pilgrims and their impact on health problems during the Hajj

BACKGROUND

The Hajj is one of the world's largest pilgrimage and gathers millions of Muslims from different nationalities every year. Communicable diseases have been reported frequently, during and following the Hajj, and these have been linked to individual behavioural measures. This study aimed to measure the effect of personal preventive measures, such as face mask use, hand hygiene and others, adopted by pilgrims in reducing the acquisition of infectious diseases.

METHODS

We conducted a cross-sectional study at the Hajj terminal in King Abdulaziz International Airport in Jeddah, Saudi Arabia. Pilgrims were approached in the airport lounges after the 2017 Hajj season and prior to the departure of their flights from Jeddah to their home countries. An electronic data collection tool ('Open Data Kit') was used to gather survey data in regards to health problems and preventive measures during the Hajj.

RESULTS

A total of 2973 Hajj pilgrims were surveyed. In all, 38.7% reported symptoms of upper respiratory tract infections (URTIs) and 5.4% reported symptoms of travel diarrhoea. Compliance with face mask use was 50.2%. Changing a face mask every 4 h was found to be significantly associated with lower prevalence of URTIs [adjusted odds ratio 0.56 (95% confidence interval 0.34-0.92), P = 0.02]. There was no statistical difference between overall face mask use and URTI acquisition. The main sources of food, eating raw vegetables/food, frequency of hand washing or use of hand sanitizers were not found to be significantly associated with reported travellers' diarrhoea. Unlicensed barbers were used by 12% of pilgrims and 9.2% of pilgrims reported using blades that were reused by other pilgrims.

CONCLUSION

Preventive measures are the most effective way to prevent infections. Pilgrims can benefit from face masks by changing them frequently. There is still limited information on the effect of the use of face mask in decreasing the risk of URTI in mass gatherings.

A rapid review of the use of face mask in preventing the spread of COVID-19

Introduction

The original use of face masks was to help protect surgical wounds from staff-generated nasal and oral bacteria. Currently governments across the world have instituted the mandatory use of masks and other face coverings so that face masks now find much broader usage in situations where close contact of people is frequent and inevitable, particularly inside public transport facilities, shopping malls and workplaces in response to the COVID-19.

Objective

We conducted a rapid review to investigate the impact face mask use has had in controlling transmission of respiratory viral infections.

Method

A rapid review was conducted in line with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidance. Five electronic databases (CINAHL, Embase, Medline, PsycINFO and Global Health) were searched from database inception to date, using pre-defined search terms. We included all studies of any design and used descriptive analysis to report summary statistics of search results. Data were extracted including sample characteristics, study design, respiratory virus being controlled, type of face masks used and their effectiveness.

Results

58 out of 84 studies met the inclusion criteria, of which 13 were classified as systematic reviews and 45 were quantitative studies (comprising randomised controlled trials, retrospective cohort studies, case control, cross-sectional, surveys, observational and descriptive studies). N = 27 studies were conducted amongst healthcare workers wearing face masks, n = 19 studies among the general population, n = 9 studies among healthcare workers the general population and patients wearing masks, and n = 3 among only patients. Face masks use have shown a great potential for preventing respiratory virus transmission including COVID-19.

Conclusion

Regardless of the type, setting, or who wears the face mask, it serves primarily a dual preventive purpose; protecting oneself from getting viral infection and protecting others. Therefore, if everyone wears a face mask in public, it offers a double barrier against COVID-19 transmission.

Community use of face masks and similar barriers to prevent respiratory illness such as COVID-19: a rapid scoping review

BackgroundEvidence for face-mask wearing in the community to protect against respiratory disease is unclear.AimTo assess effectiveness of wearing face masks in the community to prevent respiratory disease, and recommend improvements to this evidence base.MethodsWe systematically searched Scopus, Embase and MEDLINE for studies evaluating respiratory disease incidence after face-mask wearing (or not). Narrative synthesis and random-effects meta-analysis of attack rates for primary and secondary prevention were performed, subgrouped by design, setting, face barrier type, and who wore the mask. Preferred outcome was influenza-like illness. Grading of Recommendations, Assessment, Development and Evaluations (GRADE) quality assessment was undertaken and evidence base deficits described.Results33 studies (12 randomised control trials (RCTs)) were included. Mask wearing reduced primary infection by 6% (odds ratio (OR): 0.94; 95% CI: 0.75-1.19 for RCTs) to 61% (OR: 0.85; 95% CI: 0.32-2.27; OR: 0.39; 95% CI: 0.18-0.84 and OR: 0.61; 95% CI: 0.45-0.85 for cohort, case-control and cross-sectional studies respectively). RCTs suggested lowest secondary attack rates when both well and ill household members wore masks (OR: 0.81; 95% CI: 0.48-1.37). While RCTs might underestimate effects due to poor compliance and controls wearing masks, observational studies likely overestimate effects, as mask wearing might be associated with other risk-averse behaviours. GRADE was low or very low quality.ConclusionWearing face masks may reduce primary respiratory infection risk, probably by 6-15%. It is important to balance evidence from RCTs and observational studies when their conclusions widely differ and both are at risk of significant bias. COVID-19-specific studies are required.

Absenteeism and presenteeism in healthcare workers due to respiratory illness

OBJECTIVE

To assess influenza symptoms, adherence to mask use recommendations, absenteesm and presenteeism in acute care healthcare workers (HCWs) during influenza epidemics.

METHODS

The TransFLUas influenza transmission study in acute healthcare prospectively followed HCWs prospectively over 2 consecutive influenza seasons. Symptom diaries asking for respiratory symptoms and adherence with mask use recommendations were recorded on a daily basis, and study participants provided midturbinate nasal swabs for influenza testing.

RESULTS

In total, 152 HCWs (65.8% nurses and 13.2% physicians) were included: 89.1% of study participants reported at least 1 influenza symptom during their study season and 77.8% suffered from respiratory symptoms. Also, 28.3% of HCW missed at least 1 working day during the study period: 82.6% of these days were missed because of symptoms of influenza illness. Of all participating HCWs, 67.9% worked with symptoms of influenza infection on 8.8% of study days. On 0.3% of study days, symptomatic HCWs were shedding influenza virus while at work. Among HCWs with respiratory symptoms, 74.1% adhered to the policy to wear a mask at work on 59.1% of days with respiratory symptoms.

CONCLUSIONS

Respiratory disease is frequent among HCWs and imposes a significant economic burden on hospitals due to the number of working days lost. Presenteesm with respiratory illness, including influenza, is also frequent and poses a risk for patients and staff.

TRIAL REGISTRATION

NCT02478905 (clinicaltrials.gov).

Facemask against viral respiratory infections among Hajj pilgrims: A challenging cluster-randomized trial

Background

In this large-scale cluster-randomized controlled trial (cRCT) we sought to assess the effectiveness of facemasks against viral respiratory infections.

Methods and results

Over three consecutive Hajj seasons (2013, 2014, 2015) pilgrims’ tents in Makkah were allocated to ‘facemask’ or ‘no facemask’ group. Fifty facemasks were offered to participants in intervention tents, to be worn over four days, and none were offered to participants in control tents. All participants recorded facemask use and respiratory symptoms in health diaries. Nasal swabs were collected from the symptomatic for virus detection by reverse transcription polymerase chain reaction. Clinical symptoms and laboratory results were analyzed by ‘intention- to-treat’ and ‘per-protocol’. A total of 7687 adult participants from 318 tents were randomized: 3864 from 149 tents to the intervention group, and 3823 from 169 tents to the control group. Participants were aged 18 to 95 (median 34, mean 37) years, with a male to female ratio of 1:1.2. Overall, respiratory viruses were detected in 277 of 650 (43%) nasal/pharyngeal swabs collected from symptomatic pilgrims. Common viruses were rhinovirus (35.1%), influenza (4.5%) and parainfluenza (1.7%). In the intervention arm, respectively 954 (24.7%) and 1842 (47.7%) participants used facemasks daily and intermittently, while in the control arm, respectively 546 (14.3%) and 1334 (34.9%) used facemasks daily and intermittently. By intention-to-treat analysis, facemask use did not seem to be effective against laboratory-confirmed viral respiratory infections (odds ratio [OR], 1.4; 95% confidence interval [CI], 0.9 to 2.1, p = 0.18) nor against clinical respiratory infection (OR, 1.1; 95% CI, 0.9 to 1.4, p = 0.40). Similarly, in a per-protocol analysis, facemask use did not seem to be effective against laboratory-confirmed viral respiratory infections (OR 1.2, 95% CI 0.9–1.7, p = 0.26) nor against clinical respiratory infection (OR 1.3, 95% CI 1.0–1.8, p = 0.06).

Conclusion

This trial was unable to provide conclusive evidence on facemask efficacy against viral respiratory infections most likely due to poor adherence to protocol.

Face Masks Are Beneficial Regardless of the Level of Infection in the Fight Against COVID-19

Coronavirus disease 2019 (COVID-19) due to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is currently a global pandemic that has affected over 7 million people worldwide, resulting in over 400,000 deaths. In the past 20 years, they have been several viral epidemics that were primarily transmitted by respiratory droplets. The use of face masks is proven to be effective in protecting health-care workers as they perform their duties. Still, there is limited evidence about whether the widespread use of face mask would be very useful in protecting the general population. This study aimed to conduct a review to determine if face masks would be beneficial in the general population as a means of reducing the spread of COVID-19. The widespread implementation of wearing face masks by the general population is challenging due to a variety of factors. However, the extensive use of cloth masks in conjunction with other preventative measures such as social distancing and handwashing can potentially reduce the risk of transmission of COVID-19.

Infection prevention and control measures in practices of the Swiss sentinel network during seasonal influenza epidemics

Background

There are limited data on the transmission of influenza in the context of primary care practices, despite the fact that a significant proportion of the population consult their primary care physician for an influenza-like illness every year.

Aim

To describe the use of influenza prevention and control methods in private practices of the Swiss sentinel network.

Methods

This online cross-sectional survey collected data about infection prevention and control measures in the 166 private practices of the Swiss sentinel surveillance network during the 2018–2019 influenza season. Questions pertained to the practice setting, infection prevention and control recommendations, influenza vaccination status of the physicians and their staff, adhesion to hand hygiene, and mask wearing.

Findings

Among the 122 practices that answered (response rate 73.5%), 90.2% of the responding physicians had been vaccinated themselves, and 46.7% (56/120) estimated that their staff vaccination coverage was >60%, although it was offered to employees in all practices. Most practices (N=68, 55.7%) had no specific recommendations for their staff concerning mask wearing. Most physicians reported washing or disinfecting their hands before examining a patient (N=91, 74.6%), after examination (N=110, 90.2%) and before a medical procedure (N=112, 91.8%). However, this rate was lower for arrival at the practice (N=78, 63.9%) and leaving the practice (N=83, 68.0%).

Conclusion

Most physicians in the Swiss sentinel surveillance network have been vaccinated themselves. However, the vaccination rates among their staff are low, despite vaccine availability. Hand hygiene measures were also suboptimal. These results warrant further efforts to implement infection prevention and control measures in the ambulatory setting.

Particle sizes of infectious aerosols: implications for infection control

The global pandemic of COVID-19 has been associated with infections and deaths among health-care workers. This Viewpoint of infectious aerosols is intended to inform appropriate infection control measures to protect health-care workers. Studies of cough aerosols and of exhaled breath from patients with various respiratory infections have shown striking similarities in aerosol size distributions, with a predominance of pathogens in small particles (<5 μm). These are immediately respirable, suggesting the need for personal respiratory protection (respirators) for individuals in close proximity to patients with potentially virulent pathogens. There is no evidence that some pathogens are carried only in large droplets. Surgical masks might offer some respiratory protection from inhalation of infectious aerosols, but not as much as respirators. However, surgical masks worn by patients reduce exposures to infectious aerosols to health-care workers and other individuals. The variability of infectious aerosol production, with some so-called super-emitters producing much higher amounts of infectious aerosol than most, might help to explain the epidemiology of super-spreading. Airborne infection control measures are indicated for potentially lethal respiratory pathogens such as severe acute respiratory syndrome coronavirus 2.

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.

Face masks in radiation oncology clinics: based on evidence or source of mistakes?

We here express our concern about a general decree to let patients wear face masks in radiation oncology clinics. We believe that potential risks associated with wearing masks, such as the risk of confounding patients, outweigh any benefits of such a policy for which evidence of protection from COVID-19 is generally weak. For asymptomatic patients, wearing masks in addition to hygiene standards will not provide additional protection of others and should be cautioned against.

What proportion of healthcare worker masks carry virus? A systematic review

OBJECTIVE

Concerns have been raised by healthcare organisations in New Zealand that routine mask use by healthcare workers (HCW) may increase the risk of transmission of SARS-CoV-2 through increased face touching. Routine mask use by frontline HCW was not recommended when seeing 'low risk' patients. The aim of this review was to determine the carriage of respiratory viruses on facemasks used by HCW.

METHODS

A systematic review was conducted with structured searches of medical and allied health databases. Two authors independently screened articles for inclusion, with substantial agreement (k = 0.66, 95% CI 0.54-0.79). Studies that at least one author recommended for full text review were reviewed in full for inclusion. Two authors independently extracted data from included studies including the setting, method of analysis and results. There was exact agreement on the proportion of virus detected on masks.

RESULTS

We retrieved 1233 titles, 47 underwent full text review and five studies reported in four articles were included. The studies were limited by small numbers and failure to test all eligible masks in some studies. The proportion in each study ranged from 0 (95% CI 0-10) to 25% (95% CI 8-54). No study reported clinical respiratory illness as a result of virus on the masks.

CONCLUSIONS

Although limited, current evidence suggests that viral carriage on the outer surface of surgical masks worn by HCW treating patients with clinical respiratory illness is low and there was not strong evidence to support the assumption that mask use may increase the risk of viral transmission.

The adverse skin reactions of health care workers using personal protective equipment for COVID-19

In December 2019, a new coronavirus was found in Wuhan, Hubei Province, China, and spread rapidly throughout the country, attracting global attention. On February 11, the World Health Organization (WHO) officially named the disease caused by 2019-nCoV coronavirus disease 2019 (COVID-19). With the increasing number of cases, health care workers (HCWs) from all over China volunteered to work in Hubei Province. Because of the strong infectivity of COVID-19, HCWs need to wear personal protective equipment (PPE), such as N95 masks, latex gloves, and protective clothing. Due to the long-term use of PPE, many adverse skin reactions may occur. Therefore, the purpose of this study is to explore the adverse skin reactions among HCWs using PPE.Questionnaires were used for the research; a quantitative study was carried out to determine the incidence of adverse skin reactions among HCWs using PPE.A total of 61 valid questionnaires were collected. The most common adverse skin reactions among HCWs wearing N95 masks were nasal bridge scarring (68.9%) and facial itching (27.9%). The most common adverse skin reactions among HCWs wearing latex gloves were dry skin (55.7%), itching (31.2%), and rash (23.0%). The most common adverse skin reactions among HCWs wearing protective clothing were dry skin (36.1%) and itching (34.4%).When most HCWs wear PPE for a long period of time, they will experience adverse skin reactions. The incidence of adverse skin reactions to the N95 mask was 95.1%, that to latex gloves was 88.5%, and that to protective clothing was 60.7%.

On respiratory droplets and face masks

Face mask filters-textile, surgical, or respiratory-are widely used in an effort to limit the spread of airborne viral infections. Our understanding of the droplet dynamics around a face mask filter, including the droplet containment and leakage from and passing through the cover, is incomplete. We present a fluid dynamics study of the transmission of respiratory droplets through and around a face mask filter. By employing multiphase computational fluid dynamics in a fully coupled Eulerian-Lagrangian framework, we investigate the droplet dynamics induced by a mild coughing incident and examine the fluid dynamics phenomena affecting the mask efficiency. The model takes into account turbulent dispersion forces, droplet phase-change, evaporation, and breakup in addition to the droplet-droplet and droplet-air interactions. The model mimics real events by using data, which closely resemble cough experiments. The study shows that the criteria employed for assessing the face mask performance must be modified to take into account the penetration dynamics of airborne droplet transmission, the fluid dynamics leakage around the filter, and reduction of efficiency during cough cycles. A new criterion for calculating more accurately the mask efficiency by taking into account the penetration dynamics is proposed. We show that the use of masks will reduce the airborne droplet transmission and will also protect the wearer from the droplets expelled from other subjects. However, many droplets still spread around and away from the cover, cumulatively, during cough cycles. Therefore, the use of a mask does not provide complete protection, and social distancing remains important during a pandemic. The implications of the reduced mask efficiency and respiratory droplet transmission away from the mask are even more critical for healthcare workers. The results of this study provide evidence of droplet transmission prevention by face masks, which can guide their use and further improvement.

Precautions When Providing Dental Care During Coronavirus Disease 2019 (COVID-19) Pandemic

Transmission of coronavirus disease 2019 (COVID-19)—caused by novel severe acute respiratory syndrome coronavirus 2—through aerosolised saliva and respiratory droplets is possible when aerosol-generating dental procedures are performed. Consequently, dental practitioners are at increased risk of being infected when treating COVID-19 patients. A comprehensive review of the current literature on precautions when providing dental care during the COVID-19 pandemic is discussed and recommendations for dental practitioners are made. Dental practitioners should actively keep themselves abreast of the guidelines published by both national and international authorities and adhere strictly to them. Ann Acad Med Singapore 2020;49:312–19 Keywords: Aerosol-generating procedures, Infection control, Infectious disease, Severe acute respiratory syndrome coronavirus, Transmission

What every orthopaedic surgeon should know about COVID-19: A review of the current literature

The coronavirus (COVID-19) pandemic has severely affected the medical community and stopped the world in its tracks. This review aims to provide the basic information necessary for us, orthopaedic surgeons to prepare ourselves to face this pandemic together. Herein, we cover the background of COVID-19, presentation, investigations, transmission, infection control and touch upon emerging treatments. It is of paramount importance that we should stay vigilant for our patients, our families and ourselves. Adequate infection control measures are necessary during day-to-day clinical work.