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

Personal protective effect of wearing surgical face masks in public spaces on self-reported respiratory symptoms in adults: pragmatic randomised superiority trial

OBJECTIVE

To evaluate the personal protective effects of wearing versus not wearing surgical face masks in public spaces on self-reported respiratory symptoms over a 14 day period.

DESIGN

Pragmatic randomised superiority trial.

SETTING

Norway.

PARTICIPANTS

4647 adults aged ≥18 years: 2371 were assigned to the intervention arm and 2276 to the control arm.

INTERVENTIONS

Participants in the intervention arm were assigned to wear a surgical face mask in public spaces (eg, shopping centres, streets, public transport) over a 14 day period (mask wearing at home or work was not mentioned). Participants in the control arm were assigned to not wear a surgical face mask in public places.

MAIN OUTCOME MEASURES

The primary outcome was self-reported respiratory symptoms consistent with a respiratory infection. Secondary outcomes included self-reported and registered covid-19 infection.

RESULTS

Between 10 February 2023 and 27 April 2023, 4647 participants were randomised of whom 4575 (2788 women (60.9%); mean age 51.0 (standard deviation 15.0) years) were included in the intention-to-treat analysis: 2313 (50.6%) in the intervention arm and 2262 (49.4%) in the control arm. 163 events (8.9%) of self-reported symptoms consistent with respiratory infection were reported in the intervention arm and 239 (12.2%) in the control arm. The marginal odds ratio was 0.71 (95% confidence interval (CI) 0.58 to 0.87; P=0.001) favouring the face mask intervention. The absolute risk difference was -3.2% (95% CI -5.2% to -1.3%; P<0.001). No statistically significant effect was found on self- reported (marginal odds ratio 1.07, 95% CI 0.58 to 1.98; P=0.82) or registered covid-19 infection (effect estimate and 95% CI not estimable owing to lack of events in the intervention arm).

CONCLUSION

Wearing a surgical face mask in public spaces over 14 days reduces the risk of self-reported symptoms consistent with a respiratory infection, compared with not wearing a surgical face mask.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05690516.

Healthcare Provider N95 Respirator Contamination Worn Behind Face Shields With SARS-CoV-2 During Routine Clinical Care of Patients With COVID-19

N95 respirator contamination with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) during clinical care of patients with coronavirus disease 2019 is poorly understood. We performed a prospective observational study on healthcare provider's (HCP's) N95 respirators' and face shields' SARS-CoV-2 contamination during aerosol-generating procedures on SARS-CoV-2-positive patients housed in a COVID-19-specific unit. Medical masks worn on top of HCP's N95 respirators, and under face shields, during study aerosol-generating procedures were used as surrogates to detect contamination to avoid waste. Thirty-three HCPs were studied, and a total of 33 mask and 27 face shields were sampled. Masks were cut into 9 pieces and face shields were sampled twice, front and back, to determine locality of contamination; however, no positive samples were identified using standard polymerase chain reaction techniques with a CT value up to 40. All 9 mask piece samples were then pooled, as were face shield samples, using centrifugal concentration with polyethersulfone membranes. Once pooled and concentrated, overall, 9 (15%) samples were positive via real-time polymerase chain reaction: 5 from masks (15.2%) and 4 from face shields (14.8%).

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.

Evaluation of health worker acceptance and tolerance of respirators in clinical practice-An Australian perspective

BACKGROUND

One of the main infection prevention and control measures introduced during the COVID-19 pandemic was the focused application of respiratory protection to ensure health worker safety and the effective use of personal protective equipment. However, user acceptance of these strategies is paramount in sustainable compliance. This study explores various aspects of respirator use and provides recommendations to improve and maximize health worker safety. The aim of this study was to understand the relationship between respirator (P2/N95) comfort and user experience toward respiratory protection. The aim of this study was to understand the relationship between respirator (P2/N95) comfort and user experience toward respiratory protection.

METHODS

The nonexperimental cross-sectional design study was conducted in New South Wales, Australia between November and December 2022 using an anonymous self-administered online questionnaire in Microsoft Forms.

RESULTS

Of 2,514 respondents, 65% reported to have used a respirator every working day with only a few using a respirator once weekly or less (9%). Almost all respondents had completed at least one quantitative fit test (96%) prior to the survey. Fifty-nine percent reported to have experienced discomfort from wearing a respirator and the most reported adverse effect was difficulty communicating (64%), followed by skin irritation or acne (62%) and headache (56%).

CONCLUSIONS

Despite somewhat less favorable ratings on comfort and communication, health workers are in favor of respiratory protection. However, a focus on tolerance of respirators and strategies to address adverse effects from prolonged respirator use must be considered when implementing policies and procedures. Moreover, resources must be allocated to improve the design, breathability, and sustainability of a respirator along with education and training on how to use respiratory protection safely and effectively.

A systematic review of passing fit testing of the masks and respirators used during the COVID-19 pandemic: Part 1-quantitative fit test procedures

BACKGROUND

During respiratory infection pandemics, masks and respirators are highly sought after, especially for frontline healthcare workers and patients carrying respiratory viruses. The objective of this study was to systematically review fit test pass rates and identify factors influencing the fitting characteristics.

METHODS

Potentially relevant studies were identified using PubMed, Scopus, Web of Science, and Science Direct during the COVID-19 pandemic from February 5, 2020, to March 21, 2023. The search strategy using the following keywords was conducted: Quantitative Fit Test, Condensation Nuclei Counter, Controlled Negative Pressure, PortaCount, Sibata, Accufit, Fit, Seal, Mask, Respirator, Respiratory Protective Device, Respiratory Protective Equipment, Protective Device, Personal Protective Equipment, COVID-19, Coronavirus, and SARS-CoV-2. The quality of the included studies was also assessed using the Newcastle-Ottawa scale.

RESULTS

A total of 137 articles met the eligibility criteria. Fifty articles had a quality score of less than 7 (good quality). A total of 21 studies had a fit test pass rate of less than 50%. 26 studies on disposable respirators and 11 studies on reusable respirators had an FF of less than 50 and less than 200, respectively. The most influential factors include respirator brand/model, style, gender, ethnicity, facial dimensions, facial hair, age, reuse, extensive movement, seal check, comfort and usability assessment, and training.

CONCLUSION

37.36% of the disposable respirator studies and 43% of the reusable respirator studies did not report fit test results. 67.86% of the disposable respirator studies had a fit test pass rate greater than 50%, and 35.84% of these studies had an FF greater than 100. Also, 85.71% of the reusable respirator studies had a fit test pass rate greater than 50%, and 52.77% of these studies had an FF greater than 1000. Overall, the fit test pass rate was relatively acceptable. Newly developed or modified respirators must undergo reliable testing to ensure the protection of HCWs. Subject and respirator characteristics should be considered when implementing fit testing protocols. An optimal fit test panel should be developed prior to respirator design, certification, procurement decisions, and selection procedures.

Masking strategy to protect healthcare workers from COVID-19: An umbrella meta-analysis

BACKGROUND

The burden of severe disease and death due to SARS-CoV-2 (COVID-19) pandemic among healthcare workers (HCWs) worldwide has been substantial. Masking is a critical control measure to effectively protect HCWs from respiratory infectious diseases, yet for COVID-19, masking policies have varied considerably across jurisdictions. As Omicron variants began to be predominant, the value of switching from a permissive approach based on a point of care risk assessment (PCRA) to a rigid masking policy needed to be assessed.

METHODS

A literature search was conducted in MEDLINE (Ovid platform), Cochrane Library, Web of Science (Ovid platform), and PubMed to June 2022. An umbrella review of meta-analyses investigating protective effects of N95 or equivalent respirators and medical masks was then conducted. Data extraction, evidence synthesis and appraisal were duplicated.

RESULTS

While the results of Forest plots slightly favoured N95 or equivalent respirators over medical masks, eight of the ten meta-analyses included in the umbrella review were appraised as having very low certainty and the other two as having low certainty.

CONCLUSION

The literature appraisal, in conjunction with risk assessment of the Omicron variant, side-effects and acceptability to HCWs, along with the precautionary principle, supported maintaining the current policy guided by PCRA rather than adopting a more rigid approach. Well-designed prospective multi-centre trials, with systematic attention to the diversity of healthcare settings, risk levels and equity concerns are needed to support future masking policies.

Face mask use to prevent COVID-19 in clinical practice. Using a review of reviews to improve decision-making and transparency

BACKGROUND

The COVID-19 pandemic has highlighted the importance of transparency and scientific rigour in the development of clinical guidance. Rapid review methodologies were widely used in the development of guidance, and in the United Kingdom, COVID-19 guidance was criticized for methodological inadequacy and erroneous conclusions.

AIMS

To summarize the evidence looking at the use of face masks to prevent COVID-19 infection in clinical practice areas, and to show how this can be used in decision-making.

DESIGN

Overview of systematic reviews.

METHOD

Systematic reviews which included meta-analyses were sought, and data on the protective effect of face masks on COVID-19 transmission were extracted. A total of 15 papers yielded 44 effect sizes suitable for quantitative presentation, which showed wide variation in effect depending on the outcome and intervention chosen.

CONCLUSIONS

Guideline development groups need to take care to choose outcomes that are of most importance to those who are the target of guidance. Quantification of the protective effect of interventions such as different types of face mask will help nurses and others decide on the utility of their use, alongside consideration of the other factors that go into informing clinical recommendations.

IMPLICATIONS FOR PATIENT CARE AND THE PROFESSION

COVID-19 has been an unprecedented public health issue, but much clinical guidance was lacking in transparency. Nurses and other healthcare professionals have often expressed a lack of confidence in guidance. Systematic reviews reported a wide range of effect sizes. However, there was a high degree of indirectness and heterogeneity in methods and findings. To produce transparent guidance, those for whom guidance is intended should have evidence of effect where this is available.

IMPACT

Guideline authors should reflect these outcomes in their recommendations, clearly balancing both the benefits and harms of recommending face masks to prevent COVID-19.

A randomised crossover trial of two flat-fold cup respirators: BYD DE2322 N95 versus Care Essentials MSK-002 P2

BACKGROUND

The use of respiratory protection remains important in protecting health care workers from airborne pathogens such as viruses. Respirator supply is constantly changing with new models regularly becoming available. Health services should consider a broad range of factors when procuring respirators, including the results of quantitative fit testing in a representative sample of the workforce. Subjective comfort factors and compatibility with a variety of workplace tasks, such as suitability for staff use near magnetic resonance imaging (MRI) environments where relevant, should also be considered. This article compares the quantitative fit factors and user assessments for two styles of flat-fold cup respirators, Care Essentials (CE) MSK-002 P2 and BYD DE2322 N95.

METHODS

Quantitative fit tests (QNFT) were performed on 300 participants on each model of respirator in this randomised crossover trial. Participants then completed a questionnaire on their assessments of each respirator.

RESULTS

The Care Essentials MSK-002 had a significantly higher quantitative fit test pass rate than the BYD DE2322 (57% vs 18%, p < 0.001). There was no concordance between fit test pass rates for each model. Additionally, the Care Essentials MSK-002 achieved significantly higher scores on each of the responses in the subjective usability survey.

CONCLUSION

It is recommended that the Care Essentials MSK-002 be made available for health care use due to higher QNFT pass rates, higher subjective usability assessment scores, plus its potential for use in MRI environments when compared to the BYD DE2322.

How the COVID-19 Pandemic Affects Risk Awareness in Dentists: A Scoping Review

Dentists are on the frontline of infection, especially when it comes to respiratory viruses like the new coronavirus. The purpose of this paper is to conduct a scoping review to better understand dentists’ risk awareness, awareness of COVID-19 symptoms, preventive measures, and effective methods of COVID-19 infection prevention and management. This paper systematically assesses the published literature on dentistry and COVID-19. Various electronic databases including Ovid MEDLINE, Scopus, Embase, and MEDLINE via PubMed were searched up to 9 September 2021. Overall, 39 papers were included. Almost the entirety of dentists (94.5%) reported awareness of the three most common COVID-19 symptoms, and a risk awareness score of about 90% was shown, while 88.2% of dentists reported adopting preventive measures. More than 50% did not want to treat infected people. While 70.3% of dentists recommended usage of N95 masks, the rate of dentists using them was below 40%. Sufficient awareness of risks during the pandemic was found in dentists. Although they were using preventive measures, there remains upside potential for adopting all recommended measures. Further, the usage of N95 masks is improvable, even though the benefit of wearing them could not be confirmed.