Respiratory fit test panel representing population of Malaysia

BACKGROUND

The existing respiratory fit test panels (RFTPs) are based on Bivariate and Principal Component Analysis (PCA) which utilise American and Chinese head and facial dimensions. As RFTPs based on local facial anthropometric data for Malaysia are not available, this study was conducted with the aim to develop new RFTPs using Malaysian data.

METHODOLOGY

A cross-sectional study was conducted across Malaysia among 3,324 participants of the study of National Health and Morbidity Survey 2020 aged 18 and above. Ten head and facial dimensions were measured. Face length and face width were used to construct bivariate facial panel, whereas the scores from the first two PCA were used to develop the PCA panel.

RESULTS

This study showed that Malaysians have the widest upper limit for facial width. It also found that three factors could be reduced from the PCA analysis. However only 2 factors were selected with PCA 1 representing head and facial size and PCA 2 representing facial shape. Our bivariate panel could accommodate 95.0% of population, while our PCA panel accommodated 95.6%.

CONCLUSION

This was the first study to use Malaysian head and facial anthropometry data to create bivariate and PCA panels. Respirators constructed using these panels are likely to fit ≥ 95.0% of Malaysia's population.

Comparison of the inward leakage rate between N95 filtering facepiece respirators and modified surgical masks during the COVID-19 pandemic

BACKGROUND

Owing to shortage of surgical and N95 filtering facepiece respirators (FFRs) during the COVID-2019 pandemic, various masks were developed to prevent infection. This study aimed to examine the inward leakage rate (ILR) of sealed face masks and modified surgical masks using a quantitative fit test and compared it with the ILR of unmodified N95 FFRs.

METHODS

We conducted paired comparisons of ILRs of bent nose-fit wire masks, double masks, and N95 FFRs from October to December 2021. To measure the protective effectiveness of masks, participants wore masks, and the number of particles outside and inside the mask were measured. The ILR was based on the percentage of particles entering the mask using a fit tester.

RESULTS

We enrolled 54 participants (20 men and 34 women) in this study. The median ILR for surgical masks without and with a W-shaped bend in the nose-fit wire were 96.44% and 50.82%, respectively. The nose-fit wire adjustment reduced the ILR of surgical masks by a mean of 28.57%, which was significantly lower than the ILR without adjustment (P < 0.001). For double masks, with surgical or polyurethane masks on top of the W-shaped mask, the ILR did not differ significantly from that of N95. Although the filtration performance of double surgical masks matched that of N95 masks, their ILR was notably higher, indicating that double masks do not provide equivalent protection.

CONCLUSIONS

Wearing N95 masks alone is effective in many cases. However, surgical mask modifications do not guarantee consistent effectiveness. Properly selected, sealed masks with a good fit overcome leakage, emphasizing their crucial role. Without evidence, mask-wearing may lead to unexpected infections. Education based on quantitative data is crucial for preventing adverse outcomes.

The contribution of respiratory and hearing protection use to psychological distress in the workplace: a scoping review

OBJECTIVE

Workers from various industries use personal protective equipment (PPE) including masks, respirators, and hearing protection to reduce their exposures to workplace hazards. Many studies have evaluated the physiological impacts of PPE use, but few have assessed the psychological impacts. The aim of the present study was to carry out a scoping review to compile existing evidence and determine the extent of knowledge on workplace mask, respirator or hearing protection use as a psychosocial hazard (stressor) that could result in a stress response and potentially lead to psychological injury.

METHODS

The scoping review followed recognized methods and was conducted using Ovid Emcare, PubMed, Sage Journals, ScienceDirect, Scopus, SpringerLink, Google Scholar and preprint databases (OSF Preprints and medRxiv). Articles on the stressors associated with the use of masks, respirators, and hearing protection were included. The extracted data included author(s) name, year of publication, title of article, study design, population data, stressors assessed, and key findings.

RESULTS

We retrieved 650 articles after removal of duplicates, of which 26 were deemed eligible for inclusion for review. Identified factors associated with PPE use that could potentially create a stress response were identified: communication impacts, physical impacts, psychological illness symptoms, cognitive impacts, and perceived PPE-related impacts. Evidence for respirators suggest that there may be psychological injury associated with their use. However, hearing protection appears to have a protective effect in reducing psychological symptoms such as anxiety, depression, and aggression.

CONCLUSIONS

Mask or respirator use may lead to an increase in work-related stress. Whereas hearing protection may have protective effects against psychological symptoms and improves speech intelligibility. More research is needed to better understand potential psychosocial impacts of mask, respirator and/or hearing protection use.

PPE fit of healthcare workers during the COVID-19 pandemic

Historically, PPE (Personal Protective Equipment) has generally been designed around the size and shape of an average European or US white man's face and body. There is little academic evidence to support anecdotal reports that women are at a greater disadvantage than men from ill-fitting PPE. This is especially relevant in healthcare settings where women make up at least 75% of frontline workers. The COVID-19 pandemic has exacerbated problems associated with the fit of PPE that until now have been mainly anecdotal. This research presents results and analysis of a quantitative and qualitative survey concerning the fit of PPE worn by 248 healthcare workers, in a variety of healthcare roles and settings, during the COVID-19 pandemic. The analysis of the survey results showed that women were less likely than men to feel safe carrying out their roles, with only 30.5% of women and 53.3% of men stating that they felt safe all of the time. A statistically significant link is made between women suffering more with poor fit than men with certain categories of PPE (gowns, masks, visors, goggles). Over four times as many women (54.8%) as men (13.3%) reported their surgical gowns being large to some degree and women were nearly twice as likely (53.5%) to experience oversized surgical masks than men (28.6%). However, it was recognized that PPE fit problems are not exclusive to women as many men also do not conform to the underlying shape and size of PPE designs. Survey results indicated that both sexes felt equally hampered due to the fit of their PPE and around a third of both women and men had modified their PPE to address fit issues. Oversized and modified PPE presents its own set of unintended consequences. Following strict processes for doffing and removing PPE is key to virus control but doffing modified PPE can fall outside of these processes, risking cross infection. In addition, wearers of critical items of PPE (such as respirators) currently undergo a "fit test"; however, fit does not reconcile with comfort and over-tightened PPE can cause headaches, discomfort and distraction when worn for long periods. Requirements and fit tests are also not setting-specific; qualitative responses from the survey give an indication that this must be a future consideration.

Microbial contamination of powered air purifying respirators (PAPR) used by healthcare staff during the COVID-19 pandemic: an in situ microbiological study

Background

Powered air purifying respirators (PAPR) are an option for healthcare workers requiring respiratory protection during the current COVID-19 pandemic; they are shared between multiple people. PAPR hoods are intended for multiple uses by a single user and may pose an infection risk between wearers.

Methods

Internal components of PAPR hoods and corrugated air supply hoses were swabbed for evidence of bacterial, fungal, common respiratory viruses and severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) contamination.

Results

Twenty-five PAPR hoods were swabbed; 10 (40%) returned positive results. Bacterial growth was detected on six PAPR; five of the PAPR tested positive for fungal growth; all tested negative for SARS-CoV-2 and common respiratory viruses.

Conclusions

Bacteria and fungi can remain on internal components of PAPR hoods and air supply hoses despite following recommended disinfection procedures. PAPR hoods have the potential to act as fomites, cross-infecting wearers, and patients. Current guidelines for disinfecting PAPR hoods may not be effective for use in high risk healthcare environments.

Decontamination and re-use of surgical masks and respirators during the COVID-19 pandemic

OBJECTIVES

The coronavirus disease 2019 pandemic increased global demand for personal protective equipment (PPE) and resulted in shortages. The study evaluated the re-use of surgical masks and respirators by analysing their performance and safety before and after reprocessing using the following methods: oven, thermal drying, autoclave, and hydrogen peroxide plasma vapour.

METHODS

In total, 45 surgical masks and 69 respirators were decontaminated. Visual integrity, air permeability, burst resistance, pressure differential and particulate filtration efficiency of new and decontaminated surgical masks and respirators were evaluated. In addition, 14 used respirators were analysed after work shifts before and after decontamination using reverse transcription polymerase chain reaction (RT-PCR) and viral culturing. Finally, reprocessed respirators were evaluated by users in terms of functionality and comfort.

RESULTS

Oven decontamination (75 °C for 45 min) was found to be the simplest decontamination method. Physical and filtration assays indicated that all reprocessing methods were safe after one cycle. Oven decontamination maintained the characteristics of surgical masks and respirators for at least five reprocessing cycles. Viral RNA was detected by RT-PCR in two of the 14 used respirators. Four respirators submitted to viral culture were PCR-negative and culture-negative. Reprocessed respirators used in work shifts were evaluated positively by users, even after three decontamination cycles.

CONCLUSION

Oven decontamination is a safe method for reprocessing surgical masks and respirators for at least five cycles, and is feasible in the hospital setting.

Knowledge of face masks and attitudes to re-sterilisation among healthcare workers

Introduction

COVID-19 was declared a pandemic in March 2020. With the sudden surge in demand for personal protective equipment (PPE), significant concerns regarding the ongoing availability emerged. One solution proposed is re-sterilisation of respirator masks and this has been commenced in some parts of the world. On review of the literature, very little is documented regarding the knowledge of masks and the attitudes of healthcare workers towards using re-sterilised masks.

Methods

A comprehensive questionnaire was used to assess general knowledge and attitudes around facemasks and respirators.

Results

There were 190 respondents. There were significant gaps in knowledge and understanding of when particular face masks should be worn. One-third had significant concerns about ongoing availability. One-third had concerns about the quality of the masks as the pandemic continued. Only 10% of respondents underwent formal face-fitting. Eighty percent of respondents stated they would wear a re-sterilised mask. A further 15% would use a re-sterilised mask but required certain reassurances. Five percent of our respondents would not use a re-sterilised mask under any circumstances.

Discussion

Ensuring an adequate understanding of face masks is crucial among healthcare workers (HCWs) and this study highlights a need for further education. It also demonstrates a general acceptability among HCWs towards the use of re-sterilised face masks.

Supplementary Information

The online version of this article (10.1007/s11845-020-02493-z) contains supplementary material, which is available to authorized users.

Context matters: Examining the factors impacting the implementation of tuberculosis infection prevention and control guidelines in health settings in seven high tuberculosis burden countries

BACKGROUND

Healthcare workers (HCWs) in high tuberculosis (TB) burden countries are at increased risk of TB infection due to increased exposures to TB patients and inadequate implementation of TB infection prevention and control (TB IPC) measures in health settings. While various guidelines on TB IPC exist, there is little understanding of the content of these guidelines, whether they are relevant to the context and are being appropriately implemented in low-and middle-income high TB burden countries. This study aimed to critically examine the implementation of TB IPC guidelines, along with factors impacting TB IPC implementation in health settings in seven high TB burden countries.

METHODS

The WHO 2009 and national level TB IPC guidelines and the published literature from seven TB high burden countries were reviewed and relevant information extracted. Eleven key-stakeholders from the case study countries were interviewed to elucidate further facilitators and barriers impacting TB IPC guidelines implementation.

RESULTS

Our study identified that all the study countries adopted the WHO 2009 guidelines with no or minimal modifications for the local context. Therefore, the subsequent translation of the TB IPC recommendations into practice has been limited and impaired in some settings. Poor infrastructure, inadequate space for isolation, lack of TB IPC training, limited supply of personal protective equipment, the discomfort of using N95 respirators, and a high number of TB patients were some of the factors impacting the implementation of TB IPC guidelines.

CONCLUSION

The implementation of TB IPC guidelines in all seven countries was limited. It was affected by the diverse context where each of the countries and each of the facilities had a different health infrastructure and TB disease burdens. The findings warrant re-assessment of the current context prevailing in these high TB burden countries and subsequent revisions of national guidelines based to account for local context and evidence.

Health effects of wildfire smoke in children and public health tools: a narrative review

Wildfire smoke is an increasing environmental health threat to which children are particularly vulnerable, for both physiologic and behavioral reasons. To address the need for improved public health messaging this review summarizes current knowledge and knowledge gaps in the health effects of wildfire smoke in children, as well as tools for public health response aimed at children, including consideration of low-cost sensor data, respirators, and exposures in school environments. There is an established literature of health effects in children from components of ambient air pollution, which are also present in wildfire smoke, and an emerging literature on the effects of wildfire smoke, particularly for respiratory outcomes. Low-cost particulate sensors demonstrate the spatial variability of pollution, including wildfire smoke, where children live and play. Surgical masks and respirators can provide limited protection for children during wildfire events, with expected decreases of roughly 20%  and 80% for surgical masks and N95 respirators, respectively. Schools should improve filtration to reduce exposure of our nation's children to smoke during wildfire events. The evidence base described may help clinical and public health authorities provide accurate information to families to improve their decision making.

Developing a methodology to collect empirical data that informs policy and practices for stockpiling personal protective equipment

BACKGROUND

Personal protective equipment (PPE) are stockpiled across the nation to offset supply depletion during public health emergencies. Stockpiled PPE inventories vary across the United States by type, model, quantity, and the conditions in which they are stored. Over the past decade, federal, state, and local stockpile managers have had concerns for the viability of aging PPE.

METHODS

To understand factors that may affect stockpiled PPE, we explored the breadth of stockpile storage conditions and respirator and surgical gown inventories through collaboration with the national PPE community, qualitative observations collected at 10 different US stockpiles, and by compiling stockpile PPE inventories and climate data from a convenience sample of US stockpiles.

RESULTS

The aggregated inventory from 20 stockpiles is reported, accounting for approximately 53 million respirators. Most respirators (69% or 35.8 million) have been stored between 5 and 10 years. Upon visiting 10 stockpile facilities, we report on the storage conditions observed and summarize the storage environment data collected.

CONCLUSIONS

This is the first study to identify common PPE types, inventories, and storage conditions across federal, state, and local government stockpile facilities as well as health care organization-managed caches. These findings will be leveraged to guide the development of sampling protocols for air-purifying respirators and surgical gowns in US stockpiles to understand the performance viability after long-term storage.

Sterilization of polypropylene membranes of facepiece respirators by ionizing radiation

Ionizing radiation has been identified as an option for sterilization of disposable filtering facepiece respirators in situations where the production of the respirators cannot keep up with demand. Gamma radiation and high energy electrons penetrate deeply into the material and can be used to sterilize large batches of masks within a short time period. In relation to reports that sterilization by ionizing radiation reduces filtration efficiency of polypropylene membrane filters on account of static charge loss, we have demonstrated that both gamma and electron beam irradiation can be used for sterilization, provided that the respirators are recharged afterwards.

Face masks and respirators in the fight against the COVID-19 pandemic: An overview of the standards and testing methods

The COVID-19 outbreak has resulted in a shortage of personal protective equipment (PPE) throughout the world. This shortage has resulted in an increase in production of PPE to meet the demand, and as a result, several substandard equipment has entered the market. With face masks and respirators now beginning to see widespread use throughout the world, the standards and test with which they are required to undertake have become points of interest. The filtration efficiency of the masks is a key testing element that examines its ability to filter particles, bacteria and viruses; this examines the penetration efficiency percentage of each with lower results being preferable. Masks are also subjected to NaCl testing method, which allows a range of particle sizes to be examined and their penetration to be observed. The masks must also show considerable resistance to fluids and flames, to prevent the penetration of liquids and to be non-flammable. Various PPE testing protocols such as biological, chemical, fluid and flame resistances, protective ensemble, facepiece fit testing, NIOSH NaCl method and impact protection have been discussed. In addition, various tests involving bacterial and viral filtration efficiencies are also discussed. Differential pressure is examined to ascertain the comfort, airflow and breathability of the masks, whilst fit testing is examined to ensure a correct fit of the mask.

Self-reported impact of respirator use on health care worker ability to perform patient care

In a study of 1,152 health care workers surveyed prior to the COVID-19 pandemic, most disagreed that respiratory protective equipment use interferes with patient care but reported that it would affect respirator use compliance if it did. A patient's fear reaction variably influenced self-reported health care worker compliance with respirator use. Strategies to improve protective equipment design may remove potential barriers to respirator use and allow better health care worker-patient relationships.

Heat sterilisation dramatically reduces filter efficiency of the majority of FFP2 and KN-95 respirators

BACKGROUND

Because of the enormous demand for personal protective equipment and especially respiratory protective devices (respirators) during the initial phase of the corona pandemic shortages arose. Sterilisation of used respirators can reduce these shortages. In our study, respirator testing was carried out after only one sterilisation cycle.

AIM

To determine if steam sterilisation and reuse could be safely applied for used respirators.

METHODS

In a cabinet an aqueous solution of NaCl (0.02% w/v) was nebulized and passed through a sample of the material of a respirator. Passing particle concentrations were measured directly from the cabinet and via the filter material of the respirator for particles ≥ 0.3 μm, ≥ 0.5 μm and ≥ 1.0 μm.

FINDINGS

only three out of ten steam sterilised respirators met the requirements of 94% filtration efficiency.

CONCLUSION

The results prove that heat sterilisation cannot be generically applied for reuse of respirators safely.

Fume particle size distribution and fume generation rate during arc welding of cast iron

This study measured the fume particle size distribution and fume generation rate during arc welding of cast iron and estimated the generation rate of respirable dust. In addition, the generation rate of particles with a diameter of 0.3 µm or less was estimated. In this experiment, three types of filler materials (mild steel wire, stainless steel wire, and mild steel covered electrodes) with main constituents of Fe or Fe-Cr-Ni, as proposed previously by the authors, were used. The welding methods were gas metal arc welding and shielded metal arc welding. The fumes measured in this research contained 73-91% respirable dust, and the fume generation rates were in the range of 1.96-12.2 mg/s. The results of this study were as follows: (i) the welding current affects the generation rate of respirable dust, and it is highly likely that the higher the fume generation rate, the more respirable dust is generated; (ii) the generation rates of respirable dust at low and high current were highest when mild steel covered electrodes and stainless steel wire was used, respectively; and (iii) the generation rate of particles with a diameter of 0.3 µm or less was highest when stainless steel wire is used.

Filtration performances of non-medical materials as candidates for manufacturing facemasks and respirators

The recent outbreak of the coronavirus disease (COVID-19) is causing a shortage of personal protective equipment (PPE) in different countries around the world. Because the coronavirus can transmit through droplets and aerosols, facemasks and N95 respirators that require complex certification, are urgently needed. Given the situation, the U.S. Centers for Disease Control and Prevention (CDC) recommends that “in settings where facemasks are not available, healthcare personnel might use homemade masks (e.g., bandana, scarf) for the care of patients with COVID-19 as a last resort.” Although aerosols and droplets can be removed through the fibers of fabrics through a series of filtration mechanisms, their filtration performances have not been evaluated in detail. Moreover, there are a series of non-medical materials available on the market, such as household air filters, coffee filters, and different types of fabrics, which may be useful when facemasks and respirators are not available. In this study, we comprehensively evaluated the overall and size-dependent filtration performances of non-medical materials. The experiments were conducted under different face velocities to study its influence on size-dependent filtration performances. The flow resistance across these filter materials is measured as an indicator of the breathability of the materials. The results illustrate that multiple layers of household air filters are able to achieve similar filtration efficiencies compared to the N95 material without causing a significant increase in flow resistance. Considering that these air filters may shed micrometer fibers during the cutting and folding processes, it is recommended that these filters should be inserted in multiple layers of fabrics when manufacturing facemasks or respirators.

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Agencies suggest the manufacturing of homemade face masks during COVID-19.

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This work examined a wide range of non-medical materials for their filtration performance.

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We studied the influences of face velocity, number of filter material layers, and the size-dependent filtration efficiency.

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Several layers of household air filters can achieve similar filtration performance compared to N95 materials.

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The information will be crucial for healthcare personnel and the general public in manufacturing homemade face masks.

Coronavirus disease 2019 communication: novel sign language system to aid surgical tracheostomy whilst wearing a respirator

BACKGROUND

The coronavirus disease 2019 pandemic has necessitated rapid adaptations to all levels of clinical practice. Recently produced guidelines have suggested additional considerations for tracheostomy and advocated full personal protective equipment, including filtering facepiece code 3 masks. Air seal with filtering facepiece code 3 masks is often challenging, and full-face respirators and powered air-purifying respirators with hoods need to be employed. The infection prevention benefits of this equipment are accompanied by potential issues in communication.

OBJECTIVE

In an attempt to minimise surgical error through miscommunication, the authors sought to introduce a simple sign language system that could be used as an adjunct during surgery.

RESULTS

Following evaluation of pre-existing sign language platforms and consideration of multiple surgical factors, 14 bespoke hand signals were ultimately proposed.

CONCLUSION

Whilst this novel sign language system aims to bridge the communicative gap created by additional personal protective equipment, further development and validation of the proposed tool might be beneficial.

Proposal for a EN 149 acceptable reprocessing method for FFP2 respirators in times of severe shortage

INTRODUCTION

Transmission of SARS-CoV-2 to health care workers (HCW) poses a major burden in the current COVID-19 pandemic. Unprotected exposure to a COVID-19 patient is a key risk factor for HCWs. Transmission mainly occurs by droplet transmission, or by aerosol generating procedures. Respirators such as filtering face piece masks (FFP2), also called respirators, are required to prevent transmission during aerosol generating procedures, as part of the personal protective equipment (PPE) for HCWs. However, many HCW were infected due to lack of PPE, or failure to use them. Therefore, the worldwide shortage of respirators triggered the development of reprocessing used FFP2 respirators or N95 respirators as standard in the US. Our proposal with H₂O₂ plasma sterilization for decontamination allows to reprocess FFP2, while they still meet the filtration efficiency required by EN 149. The protocol is simple, uses available resources in hospitals and can be rapidly implemented to decrease the shortage of respirators during this crisis. The goal of the study was the evaluate if respirators can be reprocessed and still fulfill the requirements for filtration efficiency outlined by EN 149.

METHODS

Used FFP2 respirators - Model 3 M Aura™ 1862+ - were sterilized using a low temperature process hydrogen peroxide (H₂O₂), V-PRO® maX Low Temperature, a FDA (Food and Drug Administration) approved method to decontaminate FFP2 respirators. Decontaminated respirators were further checked for residual peroxide by a single-gas detector for H₂O₂. The total inward leakage of the protective respirators was quantitatively tested with 10 test persons in an atmosphere charged with paraffin aerosol according to the European Standard EN 149. The fit factor was calculated as the inverse of the total inward leakage.

RESULTS

Ten new and ten decontaminated FFP2 respirators were tested for filtration efficiency. None of the respirators exceeded the maximum acceptable concentration of peroxide. More than 4000 respirators have been reprocessed so far, at cost of approximately 0.3 Euro/piece.

CONCLUSIONS

FFP2 respirators can be safely reprocessed once after decontamination with plasma peroxide sterilization, whereafter they still fulfill EN 149 requirements. This allows to almost double the current number of available FFP2 respirators.

In hospital verification of non CE-marked respiratory protective devices to ensure safety of healthcare staff during the COVID-19 outbreak

AIM

To develop a protocol to ensure the quality of respiratory protective devices for healthcare workers nursing and treating patients with possible or confirmed COVID-19 in the Catharina hospital.

BACKGROUND

Due to the COVID-19 outbreak a shortage of respirators is occurring worldwide; more specifically, CE-certified FFP2 respirators. This has resulted in an increased supply to hospitals of alternative respirators of uncertain quality. Nevertheless, the quality of the respirators used by our healthcare workers must be ensured.

METHOD

A protocol and criteria based on applicable standards was developed to ensure the quality of respirators. The protocol has been implemented at the Catharina hospital and includes verification of the documents accompanying the respirator, visual inspection of the respirator and a test for total inward leak of particles into respirators.

FINDINGS

67% of the respirators brands and types received in the Catharina hospital did not meet quality criteria.

CONCLUSION

With a simple verification protocol the quality of the respirators can be checked and guaranteed while there is a shortage of the CE approved respirators which are normally used. With this in-hospital protocol health care workers can be equipped with safe-to-use respirators.

A rapid systematic review of the efficacy of face masks and respirators against coronaviruses and other respiratory transmissible viruses for the community, healthcare workers and sick patients. Int J Nurs Stud. 2020;108:103629. [PMID: 32512240 PMCID: PMC7191274 DOI: 10.1016/j.ijnurstu.2020.103629]

Background

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

Methods

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

Results

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

Conclusion

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

Preventing Transmission of Mycobacterium Tuberculosis-A Refocused Approach

Traditional tuberculosis (TB) infection control focuses on the known patient with TB, usually on appropriate treatment. A refocused, intensified TB infection control approach is presented. Combined with active case finding and rapid molecular diagnostics, an approach called FAST is described as a convenient way to call attention to the untreated patient. Natural ventilation is the mainstay of air disinfection in much of the world. Germicidal ultraviolet technology is the most sustainable approach to air disinfection under resource-limited conditions. Testing and treatment of latent TB infection works to prevent reactivation but requires greater risk targeting in both low- and high-risk settings.

The Respiratory Protection Effectiveness Clinical Trial (ResPECT): a cluster-randomized comparison of respirator and medical mask effectiveness against respiratory infections in healthcare personnel

Background

Although N95 filtering facepiece respirators and medical masks are commonly used for protection against respiratory infections in healthcare settings, more clinical evidence is needed to understand the optimal settings and exposure circumstances for healthcare personnel to use these devices. A lack of clinically germane research has led to equivocal, and occasionally conflicting, healthcare respiratory protection recommendations from public health organizations, professional societies, and experts.

Methods

The Respiratory Protection Effectiveness Clinical Trial (ResPECT) is a prospective comparison of respiratory protective equipment to be conducted at multiple U.S. study sites. Healthcare personnel who work in outpatient settings will be cluster-randomized to wear N95 respirators or medical masks for protection against infections during respiratory virus season. Outcome measures will include laboratory-confirmed viral respiratory infections, acute respiratory illness, and influenza-like illness. Participant exposures to patients, coworkers, and others with symptoms and signs of respiratory infection, both within and beyond the workplace, will be recorded in daily diaries. Adherence to study protocols will be monitored by the study team.

Discussion

ResPECT is designed to better understand the extent to which N95s and MMs reduce clinical illness among healthcare personnel. A fully successful study would produce clinically relevant results that help clinician-leaders make reasoned decisions about protection of healthcare personnel against occupationally acquired respiratory infections and prevention of spread within healthcare systems.

Trial registration

The trial is registered at clinicaltrials.gov, number NCT01249625 (11/29/2010).

Do we have enough evidence how seasonal influenza is transmitted and can be prevented in hospitals to implement a comprehensive policy?

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Vaccinated HCW 4.81, unvaccinated 7.54 lab-proven influenza episodes/100 HCWs/ season.

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2 RCTs partly directly-observed HCW mask wearing, 4 not observed underpowered, no effect on influenza transmission.

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There are no RCTs of screening HCWs/patients for influenza before entering hospital to prevent transmission.

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H₂O₂ vapor systems effectively clean patient rooms/medical equipment of influenza

Purpose

To identify if there is enough evidence at low risk-of-bias to prevent influenza transmission by vaccinating health-care workers (HCWs), patients and visitors; screening for laboratory-proven influenza all entering hospitals; screening asymptomatic individuals; identifying influenza supershedders; hand-washing and mask-wearing by HCWs, patients and visitors; and cleaning hospital rooms and equipment.

Principal Results

Vaccination reduces influenza episodes of vaccinated (4.81/100 HCW) compared to unvaccinated (7.54/100) HCWs/influenza season. A Cochrane review found for inactivated vaccines the Number Needed to Vaccinate (NNV) = 71 (95%CI 64%, 80%) for adults 18–60 (same age as HCWs) to prevent laboratory-proven influenza. There are no RCTs of screening HCWs, patients, visitors and influenza supershedders to prevent transmission. None of four RCTs of HCWs mask-wearing (two directly observed, two not) showed an effect because they were underpowered either due to small size or low circulation of influenza. Hospital rooms and equipment can effectively be cleaned of influenza by many chemicals and hydrogen peroxide vapor machines but the cleaning cycle needs shortening to increase the likelihood of adoption.

Major Conclusions

HCW vaccination is a partial solution with current vaccination levels. There are no RCTs of screening HCWs, patients and visitors demonstrating preventing influenza transmission. Only one study costed furloughing HCWs with influenza and no RCTs have identified benefits of isolating influenza supershedders. RCTs of directly- and electronically continuously-observed mask-wearing and hand-hygiene and RCTs of incentives for meticulous hygiene are required. RCTs of engineering solutions (external venting, frequent room air changes) are needed. A wide range of chemicals effectively cleans hospital rooms and equipment from influenza. Hydrogen peroxide vapor is effective against influenza and a wide range of bacterial pathogens with patient room changes, and clean areas cleaners do not clean but its cleaning cycle needs shortening to increase the likelihood of adoption of cleaning rooms vacated by influenza patients.

Novel nanoporous MnOx (x=∼1.75) sorbent for the removal of SO2 and NH3 made from MnC2O4·2H2O

In this work, nanoporous manganese oxides (MnOx) were prepared by thermal decomposition of MnC2O4·2H2O at 225°C for 6h in air. The manganese oxalate dihydrate precipitate was made from manganese sulfate and ammonium oxalate during ultrasonication and stirring. The physical properties of the oxalate precursors and the resulting MnOx samples were characterized with SEM, TGA-DSC, FTIR and powder XRD. The specific surface areas and porosity of MnOx were studied by single-point BET and multi-point N2 adsorption-desorption measurements. The amorphous MnOx from oxalate prepared by sonication showed a specific surface area as large as 499.7m(2)/g. Dynamic SO2 and NH3 flow tests indicated that the adsorption capacity of MnOx, especially for SO2, can be increased by increased surface area. Compared to the best Mn3O4-impregnated activated carbon adsorbent, nanoporous MnOx could remove approximately three times as much SO2 and a comparable amount of NH3 per gram of adsorbent. This could lead to respirators of lower weight and smaller size which will be attractive to users.

Product Failures in Respirators and Consumables: Analysis of Field Safety Notices of 2005-2013 Publicized by the Federal Institute for Drugs and Medical Devices in Germany

The current European system governed by the three EC directives 93/42/EEC (Medical Device Directive), 98/79/EC (In-Vitro Diagnostic Directive) and 90/385/EEC (Active Implantable Medical Device Directive) regulates marketing and post-market surveillance of medical devices in the European Economic Area (EEA). In cases of incidents raising the field safety corrective actions (FSCA), manufacturers have to inform the responsible Competent Authority (CA; in Germany this is the Federal Institute for Drugs and Medical Devices, BfArM) and the public by field safety notices (FSN). In this study we analyzed FSN of respirators and consumables directly required for their function, whereas devices for anesthesia and gas delivery were excluded. FSCA and FSN of 2005-2013 publicized by BfArM for the included products were analyzed with respect to the MEDDEV 2.12-1 rev. 8. In total, 60 FSCA were publicized. German and English FSN were found in 59/53 cases, respectively. FSN were clearly characterized as FSN in 44/38 cases and declaration of the type of action in 45/44 cases, respectively. Product names were provided in all cases. Lot numbers or other information for product characterization were available in 7/7 and 43/40 cases, respectively. Detailed information regarding FSCA and product malfunction was found in all cases. Information on product related risks with previous use of affected devices was provided in 42/38 cases. In 53/53 cases manufacturers provided information to mitigate product related risks. Requests to pass FSN to persons needing awareness in the organization were found in 27/24 cases. Contact data were provided in 53/48 cases, respectively. Confirmation that a CA was informed was found in 28/26 cases and in 19/15 cases a customer confirmation was included. The identified risks were: total loss of function (19/16), short circuit (1/1) and burn (3/3), and inhalation of foreign particles (1/1) which might cause severe risk to patients and users. The most frequent FSCA were product modifications and customer information. The data suggest that there is an annually increasing number of FSCA on devices included in our study. Most FSN fulfill the criteria of MEDDEV 2.12-1 rev. 8. However, there are differences between German and English FSN, e.g., regarding the distribution to persons needing awareness, missing statement that a CA was informed, and missing customer confirmation. Due to the importance of FSN for reduction of product related risks in FSCA, the type and content of FSN should be further improved.

Effectiveness of facemasks for pediatric populations against submicron-sized aerosols

BACKGROUND

In the event of a public-health threat involving bioaerosols, such as a terrorist attack or pandemic, options for devices to protect the pediatric population are limited. One strategy involves deployment of facemasks meant for the pediatric population, although protection against bioaerosols was not an intended use of such masks and little is known about their effectiveness.

METHODS

We chose 3 brands of facemasks for pediatric use for characterizing penetration. To validate our experimental technique, 2 N95 respirator brands were also tested. All barriers were subjected to neutralized polydispersed sodium chloride aerosols, and their intrinsic penetration was evaluated in the submicron size range at different flow rates.

RESULTS

As expected, the N95 brands had low penetration (5% or less) at the highest flow rates. However, for the facemasks for pediatric use, penetration varied significantly amongst brands at the highest flow rates (~15%->50%). Studies with isopropanol-dipped respirators and facemasks demonstrated that not all brands of facemasks for pediatric use have electret layers.

CONCLUSIONS

Our bench tests suggest that the intrinsic penetration through facemasks for pediatric use can be high in the submicron size range. These data can be used in risk-assessment models to determine the extent to which facemasks for pediatric use reduce the likelihood of infection in emergency situations.