Assessment of influenza virus exposure and recovery from contaminated surgical masks and N95 respirators

Photoactive decontamination and reuse of face masks

The corona virus disease 2019 (COVID-19) pandemic has led to global shortages in disposable respirators. Increasing the recycling rate of masks is a direct, low-cost strategy to mitigate COVID-19 transmission. Photoactive decontamination of used masks attracts great attention due to its fast response, remarkable virus inactivation effect and full protection integrity. Here, we review state-of-the-art situation of photoactive decontamination. The basic mechanism of photoactive decontamination is firstly discussed in terms of ultraviolet, photothermal or photocatalytic properties. Among which, ultraviolet radiation damages DNA and RNA to inactivate viruses and microorganisms, and photothermal method damages them by destroying proteins, while photocatalysis kills them by destroying the structure. The practical applications of photoactive decontamination strategies are then fully reviewed, including ultraviolet germicidal irradiation, and unconventional masks made of functional nanomaterials with photothermal or photocatalytic properties. Their performance requirements are elaborated together with the advantages of long-term recycle use. Finally, we put forward challenges and prospects for further development of photoactive decontamination technology.

Evaluating fomite risk of brown paper bags storing personal protective equipment exposed to SARS-CoV-2: A quasi-experimental study

INTRODUCTION

Literature is lacking on the safety of storing contaminated PPE in paper bags for reuse, potentially increasing exposure to frontline healthcare workers (HCW) and patients. The aim of this study is to evaluate the effectiveness of paper bags as a barrier for fomite transmission of SARS-CoV-2 by storing face masks, respirators, and face shields.

METHODS

This quasi-experimental study evaluated the presence of SARS-CoV-2 on the interior and exterior surfaces of paper bags containing PPE that had aerosolized exposures in clinical and simulated settings. Between May and October 2020, 30 unique PPE items were collected from COVID-19 units at two urban hospitals. Exposed PPE, worn by either an infected patient or HCW during a SARS-CoV-2 aerosolizing event, were placed into an unused paper bag. Samples were tested at 30-minute and 12-hour intervals.

RESULTS

A total of 177 swabs were processed from 30 PPE samples. We found a 6.8% positivity rate among all samples across both collection sites. Highest positivity rates were associated with ventilator disconnection and exposure to respiratory droplets from coughing. Positivity rates differed between hospital units. Total positivity rates were similar between 30-minute (6.7%) and 12-hour (6.9%) sample testing time intervals. Control samples exposed to inactivated SARS-CoV-2 droplets had higher total viral counts than samples exposed to nebulized aerosols.

CONCLUSIONS

Data suggests paper bags are not a significant fomite risk for SARS-CoV-2 transmission. However, controls demonstrated a risk with droplet exposure. Data can inform guidelines for storing and re-using PPE in situations of limited supplies during future pandemics.

Photosensitized Electrospun Nanofibrous Filters for Capturing and Killing Airborne Coronaviruses under Visible Light Irradiation

To address the challenge of the airborne transmission of SARS-CoV-2, photosensitized electrospun nanofibrous membranes were fabricated to effectively capture and inactivate coronavirus aerosols. With an ultrafine fiber diameter (∼200 nm) and a small pore size (∼1.5 μm), optimized membranes caught 99.2% of the aerosols of the murine hepatitis virus A59 (MHV-A59), a coronavirus surrogate for SARS-CoV-2. In addition, rose bengal was used as the photosensitizer for membranes because of its excellent reactivity in generating virucidal singlet oxygen, and the membranes rapidly inactivated 97.1% of MHV-A59 in virus-laden droplets only after 15 min irradiation of simulated reading light. Singlet oxygen damaged the virus genome and impaired virus binding to host cells, which elucidated the mechanism of disinfection at a molecular level. Membrane robustness was also evaluated, and in general, the performance of virus filtration and disinfection was maintained in artificial saliva and for long-term use. Only sunlight exposure photobleached membranes, reduced singlet oxygen production, and compromised the performance of virus disinfection. In summary, photosensitized electrospun nanofibrous membranes have been developed to capture and kill airborne environmental pathogens under ambient conditions, and they hold promise for broad applications as personal protective equipment and indoor air filters.

Porous surfaces: stability and recovery of coronaviruses

The role of indirect contact in the transmission of SARS-CoV-2 is not clear. SARS-CoV-2 persists on dry surfaces for hours to days; published studies have largely focused on hard surfaces with less research being conducted on different porous surfaces, such as textiles. Understanding the potential risks of indirect transmission of COVID-19 is useful for settings where there is close contact with textiles, including healthcare, manufacturing and retail environments. This article aims to review current research on porous surfaces in relation to their potential as fomites of coronaviruses compared to non-porous surfaces. Current methodologies for assessing the stability and recovery of coronaviruses from surfaces are also explored. Coronaviruses are often less stable on porous surfaces than non-porous surfaces, for example, SARS-CoV-2 persists for 0.5 h-5 days on paper and 3-21 days on plastic; however, stability is dependent on the type of surface. In particular, the surface properties of textiles differ widely depending on their construction, leading to variation in the stability of coronaviruses, with longer persistence on more hydrophobic materials such as polyester (1-3 days) compared to highly absorbent cotton (2 h-4 days). These findings should be considered where there is close contact with potentially contaminated textiles.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Leonurine protects against influenza A virus infection-induced pneumonia in mice

Influenza A virus (H1N1), a swine-origin influenza A virus, causes seasonal epidemics that result in severe illnesses and deaths. Leonurine has been reported to function as an anti-inflammatory agent with protective effects on nervous, urinary and cardiovascular systems. However, the therapeutic effects of leonurine on the pneumonia caused by H1N1 infection remain unclear. Hematoxylin and eosin staining was performed to evaluate the lung injuries of mice infected by H1N1. The amount of immune cells was analyzed by flow cytometry. Enzyme-linked immunosorbent assay was used to evaluate the alteration of multiple cytokines in lung tissues. Real-time quantitative polymerase chain reaction assay was performed to investigate the ribonucleic acid (RNA) levels of certain genes. The protein levels in toll-like receptor 4/nuclear factor kappa-light-chain-enhancer of activated B cells (TLR4/NF-κB) signaling were estimated by western blot assay. Leonurine treatment significantly inhibited the mortality caused by H1N1 infection. Leonurine treatment (60 mg/kg) alleviated the lung injuries caused by virus infection. The inflammatory cell accumulation and cytokine expression were inhibited by the leonurine administration. Leonurine inhibited the mRNA expression of pro-inflammatory cytokines in the lung homogenates at day 5 postinfection. Leonurine regulated the TLR4/NF-κB signaling in the lung homogenates of H1N1-infected mice at day 5 postinfection. Leonurine protects against H1N1 infection-induced pneumonia in mice.

Protective efficient comparisons among all kinds of respirators and masks for health-care workers against respiratory viruses: A PRISMA-compliant network meta-analysis

BACKGROUND

There is no definite conclusion about comparison of better effectiveness between N95 respirators and medical masks in preventing health-care workers (HCWs) from respiratory infectious diseases, so that conflicting results and recommendations regarding the protective effects may cause difficulties for selection and compliance of respiratory personal protective equipment use for HCWs, especially facing with pandemics of corona virus disease 2019.

METHODS

We systematically searched MEDLINE, Embase, PubMed, China National Knowledge Infrastructure, Wanfang, medRxiv, and Google Scholar from initiation to November 10, 2020 for randomized controlled trials, case-control studies, cohort studies, and cross-sectional studies that reported protective effects of masks or respirators for HCWs against respiratory infectious diseases. We gathered data and pooled differences in protective effects according to different types of masks, pathogens, occupations, concurrent measures, and clinical settings. The study protocol is registered with PROSPERO (registration number: 42020173279).

RESULTS

We identified 4165 articles, reviewed the full text of 66 articles selected by abstracts. Six randomized clinical trials and 26 observational studies were included finally. By 2 separate conventional meta-analyses of randomized clinical trials of common respiratory viruses and observational studies of pandemic H1N1, pooled effects show no significant difference between N95 respirators and medical masks against common respiratory viruses for laboratory-confirmed respiratory virus infection (risk ratio 0.99, 95% confidence interval [CI] 0.86-1.13, I2 = 0.0%), clinical respiratory illness (risk ratio 0.89, 95% CI 0.45-1.09, I2 = 83.7%, P = .002), influenza-like illness (risk ratio 0.75, 95% CI 0.54-1.05, I2 = 0.0%), and pandemic H1N1 for laboratory-confirmed respiratory virus infection (odds ratio 0.92, 95% CI 0.49-1.70, I2 = 0.0%, P = .967). But by network meta-analysis, N95 respirators has a significantly stronger protection for HCWs from betacoronaviruses of severe acute respiratory syndrome, middle east respiratory syndrome, and corona virus disease 2019 (odds ratio 0.43, 95% CI 0.20-0.94).

CONCLUSIONS

Our results provide moderate and very-low quality evidence of no significant difference between N95 respirators and medical masks for common respiratory viruses and pandemic H1N1, respectively. And we found low quality evidence that N95 respirators had a stronger protective effectiveness for HCWs against betacoronaviruses causative diseases compared to medical masks. The evidence of comparison between N95 respirators and medical masks for corona virus disease 2019 is open to question and needs further study.

A New Infectious Unit: Extracellular Vesicles Carrying Virus Populations

Viral egress and transmission have long been described to take place through single free virus particles. However, viruses can also shed into the environment and transmit as populations clustered inside extracellular vesicles (EVs), a process we had first called vesicle-mediated en bloc transmission. These membrane-cloaked virus clusters can originate from a variety of cellular organelles including autophagosomes, plasma membrane, and multivesicular bodies. Their viral cargo can be multiples of nonenveloped or enveloped virus particles or even naked infectious genomes, but egress is always nonlytic, with the cell remaining intact. Here we put forth the thesis that EV-cloaked viral clusters are a distinct form of infectious unit as compared to free single viruses (nonenveloped or enveloped) or even free virus aggregates. We discuss how efficient and prevalent these infectious EVs are in the context of virus-associated diseases and highlight the importance of their proper detection and disinfection for public health. Expected final online publication date for the Annual Review of Cell and Developmental Biology, Volume 37 is October 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Evaluation of survival rates of airborne microorganisms on the filter layers of commercial face masks

After the WHO designated COVID-19 a global pandemic, face masks have become a precious commodity worldwide. However, uncertainty remains around several details regarding face masks, including the potential for transmission of bioaerosols depending on the type of mask and secondary spread by face masks. Thus, understanding the interplay between face mask structure and harmful bioaerosols is essential for protecting public health. Here, we evaluated the microbial survival rate at each layer of commercial of filtering facepiece respirators (FFRs) and surgical masks (SMs) using bacterial bioaerosols. The penetration efficiency of bacterial particles for FFRs was lower than that for SMs; however, the microbial survival rate for all tested masks was >13%, regardless of filtration performance. Most bacterial particles survived in the filter layer (44%-77%) (e.g., the core filtering layer); the outer layer also exhibited significant survival rates (18%-29%). Most notably, survival rates were determined for the inner layers (<1% for FFRs, 3%-16% for SMs), which are in contact with the respiratory tract. Our comparisons of the permeability and survival rate of bioaerosols in each layer will contribute to bioaerosol-face mask research, while also providing information to facilitate the establishment of a mask-reuse protocol.

Emerging Pathogenic Unit of Vesicle-Cloaked Murine Norovirus Clusters is Resistant to Environmental Stresses and UV254 Disinfection

An individual virion was long believed to act as an independent infectious unit in virology, until the recent discovery of vesicle-cloaked virus clusters which has greatly challenged this central paradigm. Vesicle-cloaked virus clusters (also known as viral vesicles) are phospholipid-bilayer encapsulated fluid sacs that contain multiple virions or multiple copies of viral genomes. Norovirus is a global leading causative agent of gastroenteritis, and the reported prevalence of vesicle-cloaked norovirus clusters in stool has raised concerns whether the current disinfection, sanitation, and hygiene practices can effectively control environmental pollution by these pathogenic units. In this study, we have demonstrated that vesicle-cloaked murine norovirus (MNV-1) clusters were highly persistent under temperature variation (i.e., freeze-thaw) and they were partially resistant to detergent decomposition. MNV-1 vesicles were 1.89-3.17-fold more infectious in vitro than their free virus counterparts. Most importantly, MNV-1 vesicles were up to 2.16-times more resistant to UV₂₅₄ disinfection than free MNV-1 at a low viral load in vitro. Interestingly, with the increase of the viral load, free MNV-1 and MNV-1 vesicles showed equivalent resistance to UV₂₅₄ disinfection. We show that the increased multiplicity of infection provided by vesicles is in part responsible for these attributes. Our study, for the first time, sheds light on the environmental behavior of vesicle-cloaked virus clusters as unique emerging pathogenic units. Our study highlights the need to revisit current paradigms of disinfection, sanitation, and hygiene practices for protecting public health.

Is it possible to decontaminate N95 masks in pandemic times? integrative literature review

OBJECTIVE

To evaluate the protocols on decontamination/reuse of N95 masks available in the literature in times of the Covid-19 pandemic.

METHOD

Integrative literature review, in the period from 2010 to 2020, on the databases MEDLINE/PubMed, Science Direct, Cochrane, SAGE journals, Web of Science, Scopus, Embase and Wiley, with the descriptors Masks AND Respiratory protective devices; Mask OR N95 AND Covid-19; N95 AND Respirators; Decontamination AND N95 AND Coronavirus; Facemask OR Pandemic.

RESULTS

Twelve studies were included, of which 3 (30.0%) used ultraviolet germicidal irradiation and indicated mask deterioration between 2 and 10 cycles, 4 (40.0%) used hydrogen peroxide vapor, and seal loss varied from 5 to 20 cycles, 4 (33.3%) evaluated the structural integrity of the N95 mask through visual inspection and 6 (54.4%), its filtration efficiency.

CONCLUSION

Reuse strategies to overcome a shortage of devices in the face of the pandemic challenge the current concept for good practices in health-product processing.

Mask Reuse in the COVID-19 Pandemic: Creating an Inexpensive and Scalable Ultraviolet System for Filtering Facepiece Respirator Decontamination

As the current COVID-19 pandemic illustrates, not all hospitals and other patient care facilities are equipped with enough personal protective equipment to meet the demand in a crisis. Health care workers around the world use filtering facepiece respirators to protect themselves and their patients, yet during this global pandemic they are forced to reuse what are intended to be single-use masks. This poses a significant risk to these health care workers along with the people they are trying to protect. Ultraviolet germicidal irradiation (UVGI) has been validated previously as a method to effectively decontaminate these masks between use. However, not all facilities have access to the expensive commercial ultraviolet type C (UV-C) lamp decontamination equipment required for UVGI. UV-C bulbs are sitting idle in biosafety cabinets at universities and research facilities around the world that have been shuttered to slow the spread of COVID-19. These bulbs may also be available in existing medical centers where infectious diseases are commonly treated. We developed a method to modify existing light fixtures or create custom light fixtures that are compatible with new or existing UV-C bulbs. This system is scalable; can be created for less than US$50, on site and at the point of need; and leverages resources that are currently untapped and sitting unused in public and private research facilities during the pandemic. The freely accessible design can be easily modified for use around the world. Health care facilities can obtain this potentially lifesaving UVGI resource with minimal funds by collaborating with research facilities to obtain the UV-C meters and UV-C bulbs if they are unavailable from other sources. Although mask reuse is not ideal, we must do what we can in emergency situations to protect our health care workers responding to the pandemic and the communities they serve.

Community Masks During the SARS-CoV-2 Pandemic: Filtration Efficacy and Air Resistance

Background: Many countries have introduced a compulsory use of community masks for certain public areas during the SARS-CoV-2 pandemic. Different manufacturers offer reusable community masks in large quantities. The efficacy of these masks, however, is unknown. Method: We tested available community masks of major manufactures and determined the filtration efficacy using radioactive aerosol particles as well as air resistance with a vacuum measurement. Results: Filtration efficacy of the tested reusable community masks ranged from 34.9% ± 1.25% to 88.7% ± 1.18%. Air resistance ranged from 4.3 ± 0.06 to 122.4 ± 0.12 Pa/cm². There was a good correlation between filtration efficacy and air resistance (Pearson correlation 0.938, p < 0.0001). Conclusions: Filtration efficacy and air resistance differ significantly between the different community masks, but the two measurements correlate well with each other within the entire test series. For optimal protection, one should select a rather airtight mask. When selecting a mask, the highest level of tolerable air resistance can be used as a selection criterion.

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.

Risk of SARS-CoV-2 transmission by aerosols, the rational use of masks, and protection of healthcare workers from COVID-19

OBJECTIVES

To determine the risk of SARS-CoV-2 transmission by aerosols, to provide evidence on the rational use of masks, and to discuss additional measures important for the protection of healthcare workers from COVID-19.

METHODS

Literature review and expert opinion.

SHORT CONCLUSION

SARS-CoV-2, the pathogen causing COVID-19, is considered to be transmitted via droplets rather than aerosols, but droplets with strong directional airflow support may spread further than 2 m. High rates of COVID-19 infections in healthcare-workers (HCWs) have been reported from several countries. Respirators such as filtering face piece (FFP) 2 masks were designed to protect HCWs, while surgical masks were originally intended to protect patients (e.g., during surgery). Nevertheless, high quality standard surgical masks (type II/IIR according to European Norm EN 14683) appear to be as effective as FFP2 masks in preventing droplet-associated viral infections of HCWs as reported from influenza or SARS. So far, no head-to-head trials with these masks have been published for COVID-19. Neither mask type completely prevents transmission, which may be due to inappropriate handling and alternative transmission pathways. Therefore, compliance with a bundle of infection control measures including thorough hand hygiene is key. During high-risk procedures, both droplets and aerosols may be produced, reason why respirators are indicated for these interventions.

Risk of SARS-CoV-2 transmission by aerosols, the rational use of masks, and protection of healthcare workers from COVID-19

OBJECTIVES

To determine the risk of SARS-CoV-2 transmission by aerosols, to provide evidence on the rational use of masks, and to discuss additional measures important for the protection of healthcare workers from COVID-19.

METHODS

Literature review and expert opinion.

SHORT CONCLUSION

SARS-CoV-2, the pathogen causing COVID-19, is considered to be transmitted via droplets rather than aerosols, but droplets with strong directional airflow support may spread further than 2 m. High rates of COVID-19 infections in healthcare-workers (HCWs) have been reported from several countries. Respirators such as filtering face piece (FFP) 2 masks were designed to protect HCWs, while surgical masks were originally intended to protect patients (e.g., during surgery). Nevertheless, high quality standard surgical masks (type II/IIR according to European Norm EN 14683) appear to be as effective as FFP2 masks in preventing droplet-associated viral infections of HCWs as reported from influenza or SARS. So far, no head-to-head trials with these masks have been published for COVID-19. Neither mask type completely prevents transmission, which may be due to inappropriate handling and alternative transmission pathways. Therefore, compliance with a bundle of infection control measures including thorough hand hygiene is key. During high-risk procedures, both droplets and aerosols may be produced, reason why respirators are indicated for these interventions.

COVID-19 and Laparoscopic Surgery: Scoping Review of Current Literature and Local Expertise

BACKGROUND

The current coronavirus disease (COVID-19) pandemic is holding the world in its grip. Epidemiologists have shown that the mortality risks are higher when the health care system is subjected to pressure from COVID-19. It is therefore of great importance to maintain the health of health care providers and prevent contamination. An important group who will be required to treat patients with COVID-19 are health care providers during semiacute surgery. There are concerns that laparoscopic surgery increases the risk of contamination more than open surgery; therefore, balancing the safety of health care providers with the benefit of laparoscopic surgery for the patient is vital.

OBJECTIVE

We aimed to provide an overview of potential contamination routes and possible risks for health care providers; we also aimed to propose research questions based on current literature and expert opinions about performing laparoscopic surgery on patients with COVID-19.

METHODS

We performed a scoping review, adding five additional questions concerning possible contaminating routes. A systematic search was performed on the PubMed, CINAHL, and Embase databases, adding results from gray literature as well. The search not only included COVID-19 but was extended to virus contamination in general. We excluded society and professional association statements about COVID-19 if they did not add new insights to the available literature.

RESULTS

The initial search provided 2007 records, after which 267 full-text papers were considered. Finally, we used 84 papers, of which 14 discussed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Eight papers discussed the added value of performing intubation in a low-pressure operating room, mainly based on the SARS outbreak experience in 2003. Thirteen papers elaborated on the risks of intubation for health care providers and SARS-CoV-2, and 19 papers discussed this situation with other viruses. They conclude that there is significant evidence that intubation and extubation is a high-risk aerosol-producing procedure. No papers were found on the risk of SARS-CoV-2 and surgical smoke, although 25 papers did provide conflicting evidence on the infection risk of human papillomavirus, hepatitis B, polio, and rabies. No papers were found discussing tissue extraction or the deflation risk of the pneumoperitoneum after laparoscopic surgery.

CONCLUSIONS

There seems to be consensus in the literature that intubation and extubation are high-risk procedures for health care providers and that maximum protective equipment is needed. On the other hand, minimal evidence is available of the actual risk of contamination of health care providers during laparoscopy itself, nor of operating room pressure, surgical smoke, tissue extraction, or CO2 deflation. However, new studies are being published daily from current experiences, and society statements are continuously updated. There seems to be no reason to abandon laparoscopic surgery in favor of open surgery. However, the risks should not be underestimated, surgery should be performed on patients with COVID-19 only when necessary, and health care providers should use logic and common sense to protect themselves and others by performing surgery in a safe and protected environment.

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.

Obstetricians on the Coronavirus Disease 2019 (COVID-19) Front Lines and the Confusing World of Personal Protective Equipment

As health care systems struggle to maintain adequate supplies of personal protective equipment, there is confusion and anxiety among obstetricians and others about how to best protect themselves, their coworkers, and their patients. Although use of personal protective equipment is a critical strategy to protect health care personnel from coronavirus disease 2019 (COVID-19), other strategies also need to be implemented on labor and delivery units to reduce the risk of health care-associated transmission, including screening of all pregnant women who present for care (case identification), placing a mask on and rapidly isolating ill pregnant women, and minimizing the number of personnel who enter the room of an ill patient (physical distancing). Although the mechanism of transmission of COVID-19 is not known with certainty, current evidence suggests that COVID-19 is transmitted primarily through respiratory droplets. Therefore, strict adherence to hand hygiene and consistent use of recommended personal protective equipment are cornerstones for reducing transmission. In addition, it is critical that health care professionals receive training on and practice correct donning (putting on) and doffing (removing) of personal protective equipment and avoid touching their faces as well as their facial protection to minimize self-contamination.

Nosocomial Transmission of Emerging Viruses via Aerosol-Generating Medical Procedures

Recent nosocomial transmission events of emerging and re-emerging viruses, including Ebola virus, Middle East respiratory syndrome coronavirus, Nipah virus, and Crimean–Congo hemorrhagic fever orthonairovirus, have highlighted the risk of nosocomial transmission of emerging viruses in health-care settings. In particular, concerns and precautions have increased regarding the use of aerosol-generating medical procedures when treating patients with such viral infections. In spite of increasing associations between aerosol-generating medical procedures and the nosocomial transmission of viruses, we still have a poor understanding of the risks of specific procedures and viruses. In order to identify which aerosol-generating medical procedures and emerging viruses pose a high risk to health-care workers, we explore the mechanisms of aerosol-generating medical procedures, as well as the transmission pathways and characteristics of highly pathogenic viruses associated with nosocomial transmission. We then propose how research, both in clinical and experimental settings, could advance current infection control guidelines.