Which preventive measures might protect health care workers from SARS?

Efficacy of personal protective equipment to prevent environmental infection of COVID-19 among healthcare workers: a systematic review

BACKGROUND

Healthcare workers (HCWs) employed personal protective equipment (PPE) during the COVID-19 pandemic, crucial to protecting themselves from infection. To highlight the efficacy of PPE in preventing environmental infection among HCWs, a systematic review was conducted in line with PRISMA guidance.

METHODS

A search of the PubMed and Web of Science databases was conducted from January 2019 to April 2021 using pre-defined search terms. Articles were screened by three researchers. The approved papers were read in full and included in this review if relevance was mutually agreed upon. Data were extracted by study design and types of PPEs.

RESULTS

47 of 108 identified studies met the inclusion criteria, with seven reviews and meta-analyses, seven cohort, nine case-control, fifteen cross-sectional studies, four before and after, four case series, and one modeling studies. Wearing PPE offered COVID-19 protection in HCWs but required adequate training. Wearing surgical masks provided improved protection over cloth masks, while the benefit of powered air-purifying respirators is less clear, as are individual gowns, gloves, and/or face shields.

CONCLUSIONS

Wearing PPE, especially facial masks, is necessary among HCWs, while training in proper use of PPE is also important to prevent COVID-19 infection.

A domain-knowledge modeling of hospital-acquired infection risk in Healthcare personnel from retrospective observational data: A case study for COVID-19

INTRODUCTION

Hospital-acquired infections of communicable viral diseases (CVDs) have been posing a tremendous challenge to healthcare workers globally. Healthcare personnel (HCP) is facing a consistent risk of viral infections, and subsequently higher rates of morbidity and mortality.

MATERIALS AND METHODS

We proposed a domain-knowledge-driven infection risk model to quantify the individual HCP and the population-level risks. For individual-level risk estimation, a time-variant infection risk model is proposed to capture the transmission dynamics of CVDs. At the population-level, the infection risk is estimated using a Bayesian network model constructed from three feature sets, including individual-level factors, engineering control factors, and administrative control factors. For model validation, we investigated the case study of the Coronavirus disease, in which the individual-level and population-level infection risk models were applied. The data were collected from various sources such as COVID-19 transmission databases, health surveys/questionaries from medical centers, U.S. Department of Labor databases, and cross-sectional studies.

RESULTS

Regarding the individual-level risk model, the variance-based sensitivity analysis indicated that the uncertainty in the estimated risk was attributed to two variables: the number of close contacts and the viral transmission probability. Next, the disease transmission probability was computed using a multivariate logistic regression applied for a cross-sectional HCP data in the UK, with the 10-fold cross-validation accuracy of 78.23%. Combined with the previous result, we further validated the individual infection risk model by considering six occupations in the U.S. Department of Labor O*Net database. The occupation-specific risk evaluation suggested that the registered nurses, medical assistants, and respiratory therapists were the highest-risk occupations. For the population-level risk model validation, the infection risk in Texas and California was estimated, in which the infection risk in Texas was lower than that in California. This can be explained by California's higher patient load for each HCP per day and lower personal protective equipment (PPE) sufficiency level.

CONCLUSION

The accurate estimation of infection risk at both individual level and population levels using our domain-knowledge-driven infection risk model will significantly enhance the PPE allocation, safety plans for HCP, and hospital staffing strategies.

WASH to control COVID-19: A rapid review

Background

Preventive public health has been suggested as methods for reducing the transmission of COVID-19. Safety and efficacy of one such public health measure: WASH intervention for COVID-19 has not been systematically reviewed. We undertook a rapid review to assess the effect of WASH intervention in reducing the incidence of COVID-19.

Methods

We conducted searches in PubMed, MEDLINE, and EMBASE. We undertook screening of studies in two stages and extracted data and assessed the quality of evidence for the primary outcome using GRADE recommendations.

Main results

We included a total of 13 studies with three studies on COVID-19 and 10 on SARS. The study found that hand washing, sterilization of hands, gargling, cleaning/shower after attending patients of COVID-19, or SARS was protective. Evidence also found that frequent washes can prevent SARS transmission among HCWs. However; one study reported that due to enhanced infection-prevention measures, front-line HCWs are more prone to hand-skin damage. The certainty of the evidence for our primary outcome as per GRADE was very low. We did not find any studies that assessed the effect of WASH on hospitalizations, and mortality due to COVID-19. Also; we did not find any study that compared WASH interventions with any other public health measures.

Conclusions

Current evidence of WASH interventions for COVID-19 is limited as it is largely based on indirect evidence from SARS. Findings from the included studies consistently show that WASH is important in reducing the number of cases during a pandemic. Timely implementation of WASH along with other public health interventions can be vital to ensure the desired success. Further good-quality studies providing direct evidence of the efficacy of WASH on COVID-19 are needed.

Risk of transmission of respiratory viruses during aerosol-generating medical procedures (AGMPs) revisited in the COVID-19 pandemic: a systematic review

BACKGROUND

In many jurisdictions healthcare workers (HCWs) are using respirators for aerosol-generating medical procedures (AGMPs) performed on adult and pediatric populations with all suspect/confirmed viral respiratory infections (VRIs). This systematic review assessed the risk of VRIs to HCWs in the presence of AGMPs, the role respirators versus medical/surgical masks have on reducing that risk, and if the risk to HCWs during AGMPs differed when caring for adult or pediatric patient populations.

MAIN TEXT

We searched MEDLINE, EMBASE, Cochrane Central, Cochrane SR, CINAHL, COVID-19 specific resources, and MedRxiv for English and French articles from database inception to September 9, 2021. Independent reviewers screened abstracts using pre-defined criteria, reviewed full-text articles, selected relevant studies, abstracted data, and conducted quality assessments of all studies using the ROBINS-I risk of bias tool. Disagreements were resolved by consensus. Thirty-eight studies were included; 23 studies on COVID-19, 10 on SARS, and 5 on MERS/ influenza/other respiratory viruses. Two of the 16 studies which assessed associations found that HCWs were 1.7 to 2.5 times more likely to contract COVID-19 after exposure to AGMPs vs. not exposed to AGMPs. Eight studies reported statistically significant associations for nine specific AGMPs and transmission of SARS to HCWS. Intubation was consistently associated with an increased risk of SARS. HCWs were more likely (OR 2.05, 95% CI 1.2-3.4) to contract human coronaviruses when exposed to an AGMP in one study. There were no reported associations between AGMP exposure and transmission of influenza or in a single study on MERS. There was limited evidence supporting the use of a respirator over a medical/surgical mask during an AGMP to reduce the risk of viral transmission. One study described outcomes of HCWs exposed to a pediatric patient during intubation.

CONCLUSION

Exposure to an AGMP may increase the risk of transmission of COVID-19, SARS, and human coronaviruses to HCWs, however the evidence base is heterogenous and prone to confounding, particularly related to COVID-19. There continues to be a significant research gap in the epidemiology of the risk of VRIs among HCWs during AGMPs, particularly for pediatric patients. Further evidence is needed regarding what constitutes an AGMP.

Indian Guidelines on Nebulization Therapy

Inhalational therapy, today, happens to be the mainstay of treatment in obstructive airway diseases (OADs), such as asthma, chronic obstructive pulmonary disease (COPD), and is also in the present, used in a variety of other pulmonary and even non-pulmonary disorders. Hand-held inhalation devices may often be difficult to use, particularly for children, elderly, debilitated or distressed patients. Nebulization therapy emerges as a good option in these cases besides being useful in the home care, emergency room and critical care settings. With so many advancements taking place in nebulizer technology; availability of a plethora of drug formulations for its use, and the widening scope of this therapy; medical practitioners, respiratory therapists, and other health care personnel face the challenge of choosing appropriate inhalation devices and drug formulations, besides their rational application and use in different clinical situations. Adequate maintenance of nebulizer equipment including their disinfection and storage are the other relevant issues requiring guidance. Injudicious and improper use of nebulizers and their poor maintenance can sometimes lead to serious health hazards, nosocomial infections, transmission of infection, and other adverse outcomes. Thus, it is imperative to have a proper national guideline on nebulization practices to bridge the knowledge gaps amongst various health care personnel involved in this practice. It will also serve as an educational and scientific resource for healthcare professionals, as well as promote future research by identifying neglected and ignored areas in this field. Such comprehensive guidelines on this subject have not been available in the country and the only available proper international guidelines were released in 1997 which have not been updated for a noticeably long period of over two decades, though many changes and advancements have taken place in this technology in the recent past. Much of nebulization practices in the present may not be evidence-based and even some of these, the way they are currently used, may be ineffective or even harmful. Recognizing the knowledge deficit and paucity of guidelines on the usage of nebulizers in various settings such as inpatient, out-patient, emergency room, critical care, and domiciliary use in India in a wide variety of indications to standardize nebulization practices and to address many other related issues; National College of Chest Physicians (India), commissioned a National task force consisting of eminent experts in the field of Pulmonary Medicine from different backgrounds and different parts of the country to review the available evidence from the medical literature on the scientific principles and clinical practices of nebulization therapy and to formulate evidence-based guidelines on it. The guideline is based on all possible literature that could be explored with the best available evidence and incorporating expert opinions. To support the guideline with high-quality evidence, a systematic search of the electronic databases was performed to identify the relevant studies, position papers, consensus reports, and recommendations published. Rating of the level of the quality of evidence and the strength of recommendation was done using the GRADE system. Six topics were identified, each given to one group of experts comprising of advisors, chairpersons, convenor and members, and such six groups (A-F) were formed and the consensus recommendations of each group was included as a section in the guidelines (Sections I to VI). The topics included were: A. Introduction, basic principles and technical aspects of nebulization, types of equipment, their choice, use, and maintenance B. Nebulization therapy in obstructive airway diseases C. Nebulization therapy in the intensive care unit D. Use of various drugs (other than bronchodilators and inhaled corticosteroids) by nebulized route and miscellaneous uses of nebulization therapy E. Domiciliary/Home/Maintenance nebulization therapy; public & health care workers education, and F. Nebulization therapy in COVID-19 pandemic and in patients of other contagious viral respiratory infections (included later considering the crisis created due to COVID-19 pandemic). Various issues in different sections have been discussed in the form of questions, followed by point-wise evidence statements based on the existing knowledge, and recommendations have been formulated.

SARS-CoV-2 transmission risk to healthcare workers performing tracheostomies: a systematic review

BACKGROUND

Tracheostomy is a commonly performed procedure in patients with coronavirus disease 2019 (COVID-19) receiving mechanical ventilation (MV). This review aims to investigate the occurrence of SARS-CoV-2 transmission from patients to healthcare workers (HCWs) when tracheostomies are performed.

METHODS

This systematic review used the preferred reporting items for systematic reviews and meta-analysis framework. Studies reporting SARS-CoV-2 infection in HCWs involved in tracheostomy procedures were included.

RESULTS

Sixty-nine studies (between 01/11/2019 and 16/01/2022) reporting 3117 tracheostomy events were included, 45.9% (1430/3117) were performed surgically. The mean time from MV initiation to tracheostomy was 16.7 ± 7.9 days. Location of tracheostomy, personal protective equipment used, and anaesthesia technique varied between studies. The mean procedure duration was 14.1 ± 7.5 minutes; was statistically longer for percutaneous tracheostomies compared with surgical tracheostomies (mean duration 17.5 ± 7.0 versus 15.5 ± 5.6 minutes, p = 0.02). Across 5 out of 69 studies that reported 311 tracheostomies, 34 HCWs tested positive for SARS-CoV-2 and 23/34 (67.6%) were associated with percutaneous tracheostomies.

CONCLUSIONS

In this systematic review we found that SARS-CoV-2 transmission to HCWs performing or assisting with a tracheostomy procedure appeared to be low, with all reported transmissions occurring in 2020, prior to vaccinations and more recent strains of SARS-CoV-2. Transmissions may be higher with percutaneous tracheostomies. However, an accurate estimation of infection risk was not possible in the absence of the actual number of HCWs exposed to the risk during the procedure and the inability to control for multiple confounders related to variable timing, technique, and infection control practices.

Air Quality in Dental Care Facilities: Update to Current Management and Control Strategies Implementing New Technologies: A Comprehensive Review

The quality of indoor air in healthcare facilities, with an emphasis on dental offices, attracted the attention of the scientific community in the late 1960s. Since then, it has become evident that the indoor air quality is critical in modern dental care facilities for limiting the spread of airborne infections, including vaccine-preventable diseases, and a key component of safety for healthcare personnel and patients. In the past decades, the role of indoor air quality has also been recognized in non-healthcare facilities, given the increasing time spent indoors by humans. During the provision of dental care services, mainly in the field of restorative dentistry, high-speed dental handpieces emitting air and water are used, producing large quantities of aerosol and hovering inside the operations area. In modern dental offices, new devices emitting air/powder for cavities improvement and cleaning as well as for periodontal prophylactic cleaning and aesthetics are used. In addition, a new therapeutic protocol for the removal of bacterial biofilm, targeting treatment for peri-implant diseases and conditions using air-abrasive decontamination technology, has been introduced in daily dental practice. The aim of this non-systemic review is to present the current state of knowledge on the nature and dynamics of air splatters and to provide an update to management and control strategies in dental care facilities, focusing on air purification and ultraviolet devices proposed and used. The findings arising from the limited number of related published articles documenting the reduction in levels of particular matter 2.5 (PM2.5), PM10 and volatile organic compounds, allow us to conclude that the continuous operation of air purifiers during and after treatment, contributes considerably to the improvement of the indoor air quality in dental care facilities. Moreover, the utilization of air purifiers is highly recommended in dental practice to mitigate spread of infections, including vaccine-preventable diseases. Frequent cleaning and maintenance of the purifier sieves and filters and frequent renovation of the indoor air through physical ventilation by mean of open windows is imperative. More research on environmental contamination and particularly on viral contamination under real dental care conditions is needed.

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.

Measurement of airborne particle emission during surgical and percutaneous dilatational tracheostomy COVID-19 adapted procedures in a swine model: Experimental report and review of literature

INTRODUCTION

Surgical tracheostomy (ST) and Percutaneous dilatational tracheostomy (PDT) are classified as high-risk aerosol-generating procedures and might lead to healthcare workers (HCW) infection. Albeit the COVID-19 strain slightly released since the vaccination era, preventing HCW from infection remains a major economical and medical concern. To date, there is no study monitoring particle emissions during ST and PDT in a clinical setting. The aim of this study was to monitor particle emissions during ST and PDT in a swine model.

METHODS

A randomized animal study on swine model with induced acute respiratory distress syndrome (ARDS) was conducted. A dedicated room with controlled airflow was used to standardize the measurements obtained using an airborne optical particle counter. 6 ST and 6 PDT were performed in 12 pigs. Airborne particles (diameter of 0.5 to 3 μm) were continuously measured; video and audio data were recorded. The emission of particles was considered as significant if the number of particles increased beyond the normal variations of baseline particle contamination determinations in the room. These significant emissions were interpreted in the light of video and audio recordings. Duration of procedures, number of expiratory pauses, technical errors and adverse events were also analyzed.

RESULTS

10 procedures (5 ST and 5 PDT) were fully analyzable. There was no systematic aerosolization during procedures. However, in 1/5 ST and 4/5 PDT, minor leaks and some adverse events (cuff perforation in 1 ST and 1 PDT) occurred. Human factors were responsible for 1 aerosolization during 1 PDT procedure. ST duration was significantly shorter than PDT (8.6 ± 1.3 vs 15.6 ± 1.9 minutes) and required less expiratory pauses (1 vs 6.8 ± 1.2).

CONCLUSIONS

COVID-19 adaptations allow preventing for major aerosol leaks for both ST and PDT, contributing to preserving healthcare workers during COVID-19 outbreak, but failed to achieve a perfectly airtight procedure. However, with COVID-19 adaptations, PDT required more expiratory pauses and more time than ST. Human factors and adverse events may lead to aerosolization and might be more frequent in PDT.

Efficacy of face masks against respiratory infectious diseases: a systematic review and network analysis of randomized-controlled trials

During the ongoing COVID-19 pandemic, face masks are among the most common and practical control measures used globally in reducing the risk of infection and disease transmission. Although several studies have investigated the efficacy of various face masks and respirators in preventing infection, the results have been inconsistent. Therefore, we performed a systematic review and network meta-analysis (NMA) of the randomized-controlled trials (RCTs) to assess the actual efficacy of face masks in preventing respiratory infections. We searched nine electronic databases up to July 2020 to find potential articles. We accepted trials reporting the protective efficacy of face masks against respiratory infections, of which the primary endpoint was the presence of respiratory infections. We used the ROB-2 Cochrane tool to grade the trial quality. We initially registered the protocol for this study in PROSPERO (CRD42020178516). Sixteen RCTs involving 17 048 individuals were included for NMA. Overall, evidence was weak, lacking statistical power due to the small number of participants, and there was substantial inconsistency in our findings. In comparison to those without face masks, participants with fit-tested N95 respirators were likely to have lesser infection risk (RR 0.67, 95% CI 0.38-1.19,P-score 0.80), followed by those with non-fit-tested N95 and non-fit-tested FFP2 respirators that shared the similar risk, (RR 0.73, 95% CI 0.12-4.36,P-score 0.63) and (RR 0.80, 95% CI 0.38-1.71,P-score 0.63), respectively. Next, participants who donned face masks with and without hand hygiene practices showed modest risk improvement alike (RR 0.89, 95% CI 0.67-1.17,P-score 0.55) and (RR 0.92, 95% CI 0.70-1.22,P-score 0.51). Otherwise, participants donning double-layered cloth masks were prone to infection (RR 4.80, 95% CI 1.42-16.27,P-score 0.01). Eleven out of 16 RCTs that underwent a pairwise meta-analysis revealed a substantially lower infection risk in those donning medical face masks (MFMs) than those without face masks (RR 0.83 95% CI 0.71-0.96). Given the body of evidence through a systematic review and meta-analyses, our findings supported the protective benefits of MFMs in reducing respiratory transmissions, and the universal mask-wearing should be applied-especially during the COVID-19 pandemic. More clinical data is required to conclude the efficiency of cloth masks; in the short term, users should not use cloth face masks in the outbreak hot spots and places where social distancing is impossible.

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.

Percutaneous tracheostomy in COVID-19 patients: a new apneic approach

Background

Percutaneous dilation tracheostomy is an aerosol-generating procedure carrying a documented infectious risk during respiratory virus pandemics. For this reason, during the COVID-19 outbreak, surgical tracheostomy was preferred to the percutaneous one, despite the technique related complications increased risk.

Methods

We describe a new sequence for percutaneous dilation tracheostomy procedure that could be considered safe both for patients and healthcare personnel. A fiberscope was connected to a video unit to allow bronchoscopy. Guidewire positioning was performed as usual. While the established standard procedure continues with the creation of the stoma without any change in mechanical ventilation, we retracted the bronchoscope until immediately after the access valve in the mount tube, allowing normal ventilation. After 3 minutes of ventilation with 100% oxygen, mechanical ventilation was stopped without disconnecting the circuit. During apnea, the stoma was created by dilating the trachea and the tracheostomy cannula was inserted. Ventilation was then resumed. We evaluated the safeness of the procedure by recording any severe desaturation and by performing serological tests to all personnel.

Results

Thirty-six patients (38%) of 96 underwent tracheostomy; 22 (23%) percutaneous dilation tracheostomies with the new approach were performed without any desaturation. All personnel (150 operators) were evaluated for serological testing: 9 (6%) had positive serology but none of them had participated in tracheostomy procedures.

Conclusion

This newly described percutaneous dilation tracheostomy technique was not related to severe desaturation events and we did not observe any positive serological test in health workers who performed the tracheostomies.

Quantifying Viral Particle Aerosolization Risk During Tracheostomy Surgery and Tracheostomy Care

Importance

During respiratory disease outbreaks such as the COVID-19 pandemic, aerosol-generating procedures, including tracheostomy, are associated with the risk of viral transmission to health care workers.

Objective

To quantify particle aerosolization during tracheostomy surgery and tracheostomy care and to evaluate interventions that minimize the risk of viral particle exposure.

Design, Setting, and Participants

This comparative effectiveness study was conducted from August 2020 to January 2021 at a tertiary care academic institution. Aerosol generation was measured in real time with an optical particle counter during simulated (manikin) tracheostomy surgical and clinical conditions, including cough, airway nebulization, open suctioning, and electrocautery. Aerosol sampling was also performed during in vivo swine tracheostomy procedures (n = 4), with or without electrocautery. Fluorescent dye was used to visualize cough spread onto the surgical field during swine tracheostomy. Finally, 6 tracheostomy coverings were compared with no tracheostomy covering to quantify reduction in particle aerosolization.

Main Outcomes and Measures

Respirable aerosolized particle concentration.

Results

Cough, airway humidification, open suctioning, and electrocautery produced aerosol particles substantially above baseline. Compared with uncovered tracheostomy, decreased aerosolization was found with the use of tracheostomy coverings, including a cotton mask (73.8% [(95% CI, 63.0%-84.5%]; d = 3.8), polyester gaiter 79.5% [95% CI, 68.7%-90.3%]; d = 7.2), humidification mask (82.8% [95% CI, 72.0%-93.7%]; d = 8.6), heat moisture exchanger (HME) (91.0% [95% CI, 80.2%-101.7%]; d = 19.0), and surgical mask (89.9% [95% CI, 79.3%-100.6%]; d = 12.8). Simultaneous use of a surgical mask and HME decreased the particle concentration compared with either the HME (95% CI, 1.6%-12.3%; Cohen d = 1.2) or surgical mask (95% CI, 2.7%-13.2%; d = 1.9) used independently. Procedures performed with electrocautery increased total aerosolized particles by 1500 particles/m3 per 5-second interval (95% CI, 1380-1610 particles/m3 per 5-second interval; d = 1.8).

Conclusions and Relevance

The findings of this laboratory and animal comparative effectiveness study indicate that tracheostomy surgery and tracheostomy care are associated with significant aerosol generation, putting health care workers at risk for viral transmission of airborne diseases. Combined HME and surgical mask coverage of the tracheostomy was associated with decreased aerosolization, thereby reducing the risk of viral transmission to health care workers.

Transmission of Severe Acute Respiratory Syndrome Coronavirus 1 and Severe Acute Respiratory Syndrome Coronavirus 2 During Aerosol-Generating Procedures in Critical Care: A Systematic Review and Meta-Analysis of Observational Studies

OBJECTIVES

To assess the risk of coronavirus transmission to healthcare workers performing aerosol-generating procedures and the potential benefits of personal protective equipment during these procedures.

DATA SOURCES

MEDLINE, EMBASE, and Cochrane CENTRAL were searched using a combination of related MeSH terms and keywords.

STUDY SELECTION

Cohort studies and case controls investigating common anesthetic and critical care aerosol-generating procedures and transmission of severe acute respiratory syndrome coronavirus 1, Middle East respiratory syndrome coronavirus, and severe acute respiratory syndrome coronavirus 2 to healthcare workers were included for quantitative analysis.

DATA EXTRACTION

Qualitative and quantitative data on the transmission of severe acute respiratory syndrome coronavirus 1, severe acute respiratory syndrome coronavirus 2, and Middle East respiratory syndrome coronavirus to healthcare workers via aerosol-generating procedures in anesthesia and critical care were collected independently. The Risk Of Bias In Non-randomized Studies - of Interventions tool was used to assess the risk of bias of included studies.

DATA SYNTHESIS

Seventeen studies out of 2,676 yielded records were included for meta-analyses. Endotracheal intubation (odds ratio, 6.69, 95% CI, 3.81-11.72; p < 0.001), noninvasive ventilation (odds ratio, 3.65; 95% CI, 1.86-7.19; p < 0.001), and administration of nebulized medications (odds ratio, 10.03; 95% CI, 1.98-50.69; p = 0.005) were found to increase the odds of healthcare workers contracting severe acute respiratory syndrome coronavirus 1 or severe acute respiratory syndrome coronavirus 2. The use of N95 masks (odds ratio, 0.11; 95% CI, 0.03-0.39; p < 0.001), gowns (odds ratio, 0.59; 95% CI, 0.48-0.73; p < 0.001), and gloves (odds ratio, 0.39; 95% CI, 0.29-0.53; p < 0.001) were found to be significantly protective of healthcare workers from contracting severe acute respiratory syndrome coronavirus 1 or severe acute respiratory syndrome coronavirus 2.

CONCLUSIONS

Specific aerosol-generating procedures are high risk for the transmission of severe acute respiratory syndrome coronavirus 1 and severe acute respiratory syndrome coronavirus 2 from patients to healthcare workers. Personal protective equipment reduce the odds of contracting severe acute respiratory syndrome coronavirus 1 and severe acute respiratory syndrome coronavirus 2.

Apneic Tracheostomy in COVID-19 Patients on Veno-Venous Extracorporeal Membrane Oxygenation

COVID-19 creates an impressive burden for intensive care units in terms of need for advanced respiratory care, with a huge number of acute respiratory distress syndromes (ARDS) requiring prolonged mechanical ventilation. In some cases, this proves to be insufficient, with a refractory respiratory failure calling for an extracorporeal approach (veno-venous ECMO). In this scenario, most of these patients need an early tracheostomy procedure to be carried out, which creates the risk of distribution of aerosol particles, possibly leading to personnel infection. The use of apneic tracheostomy has been proposed for COVID-19 patients, but in case of ECMO it may produce lung derecruitment, severe hypoxemia, and sudden worsening of respiratory mechanics. We developed an apneic tracheostomy technique and applied it in over 32 patients supported by veno-venous ECMO. We present data showing the safety and feasibility of this technique in terms of patient care and personnel protection. Gas exchange and pH did not show statistically significant changes after the tracheostomy, nor did respiratory mechanics data or the need for inspiratory pressure and FiO₂. The use of apneic tracheostomy was a safe option for patient care during ECMO and reduced the possibility of virus spreading.

Aerosol generation during phacoemulsification in live patient cataract surgery environment

PURPOSE

To investigate whether phacoemulsification is an aerosol-generating procedure in a live patient environment.

SETTING

New Hayesbank Ophthalmology Services, Kent, United Kingdom.

DESIGN

In vivo experimental human eyes study.

METHODS

Aerosol particle counts sized 0.3 μm or lesser, more than 0.3 to 0.5 μm or lesser, more than 0.5 to 1 μm or lesser, more than 1 to 2.5 μm or lesser, more than 2.5 to 5 μm or lesser, and more than 5 to 10 μm or lesser were measured during elective phacoemulsification surgery of 25 eyes. The baseline particle count in the operating theater was measured on 2 separate days to assess for fluctuation. Then, 5 readings each during prephacoemulsification and phacoemulsification of all eyes were measured. The difference in aerosol generation during prephacoemulsification and phacoemulsification was also measured with the use of the mobile laminar air flow (LAF) machine. Finally, aerosol generation during phacoemulsification was measured using 2% hydroxypropyl methylcellulose (HPMC).

RESULTS

There was no statistically significant difference in measurement of aerosol between the baseline measurements on both days and between each patient's prephacoemulsification and phacoemulsification stages of surgery. The LAF system showed statistically significant reduction in particles size of 0.3 μm or lesser, more than 0.3 to 0.5 μm or lesser, more than 0.5 to 1 μm or lesser, more than 1 to 2.5 μm or lesser, more than 2.5 to 5 μm or lesser, and more than 5 to 10 μm during phacoemulsification compared with that during prephacoemulsification (P value .00 for all particle sizes, t test). The use of 2% HPMC did not show any statistically significant reduction in particle measurements.

CONCLUSIONS

Aerosol particles sized less than 10 μm are not produced during phacoemulsification of human crystalline lens in a live patient setting. The use of a mobile LAF machine significantly reduced the number of particles sized 10 μm or lesser within the surgical field.

Eye Protection in ENT Practice During the COVID-19 Pandemic

Objectives

There is a lack of evidence-based guidelines with regard to eye protection for aerosol-generating procedures in otolaryngology practice. In addition, some recommended personal protective equipment (PPE) is not compatible with commonly used ENT equipment. This study aims to investigate the degree of eye protection that commonly used PPE gives.

Study Design

Simulation model.

Setting

Simulation laboratory.

Methods

A custom-built setup was utilized to simulate the clinical scenario of a patient cough in proximity of a health care worker. A system that sprays a xanthan-fluorescein mixture was set up and calibrated to simulate a human cough. A mannequin with cellulose paper placed on its forehead, eyes, and mouth was fitted with various PPE combinations and exposed to the simulated cough. The degree of contamination on the cellulose papers was quantified with a fluorescent microscope able to detect aerosols ≥10 µm.

Results

When no eye protection was worn, 278 droplets/aerosols reached the eye area. The use of the surgical mask with an attached upward-facing shield alone resulted in only 2 droplets/aerosols reaching the eye area. In this experiment, safety glasses and goggles performed equally, as the addition of either brought the number of droplets/aerosols reaching the eye down to 0.

Conclusion

When used with an upward-facing face shield, there was no difference in the eye protection rendered by safety goggles or glasses in this study. Safety glasses may be considered a viable alternative to safety goggles in aerosol-generating procedures.

Aerosol Transmission of Coronavirus and Influenza Virus of Animal Origin

Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused great harm to global public health, resulting in a large number of infections among the population. However, the epidemiology of coronavirus has not been fully understood, especially the mechanism of aerosol transmission. Many respiratory viruses can spread via contact and droplet transmission, but increasing epidemiological data have shown that viral aerosol is an essential transmission route of coronavirus and influenza virus due to its ability to spread rapidly and high infectiousness. Aerosols have the characteristics of small particle size, long-time suspension and long-distance transmission, and easy access to the deep respiratory tract, leading to a high infection risk and posing a great threat to public health. In this review, the characteristics of viral aerosol generation, transmission, and infection as well as the current advances in the aerosol transmission of zoonotic coronavirus and influenza virus are summarized. The aim of the review is to strengthen the understanding of viral aerosol transmission and provide a scientific basis for the prevention and control of these diseases.

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

BACKGROUND

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

METHODOLOGY

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

RESULTS

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

CONCLUSIONS

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

Bronchoscopy during the COVID-19 pandemic: effect on current practices and strategies to reduce procedure-associated transmission

Introduction: Bronchoscopy and related procedures have unambiguously been affected during the Corona Virus Disease 2019 (COVID-19) pandemic caused by Severe Acute Respiratory Syndrome-Corona Virus-2 (SARS COV-2). Ordinary bronchoscopy practices and lung cancer services might have changed over this pandemic and for the years to come.Areas covered: This manuscript summarizes the utility of bronchoscopy in COVID-19 patients, and the impact of the pandemic in lung cancer diagnostic services, in view of possible viral spread during these We conducted a literature review of articles published in PubMed/Medline from inception to November 5th, 2020 using relevant terms.Expert opinion: Without doubt this pandemic has changed the way bronchoscopy and related procedures are being performed. Mandatory universal personal protective equipment, pre-bronchoscopy PCR tests, dedicated protective barriers and disposable bronchoscopes might be the safest and simpler way to perform even the most complicated procedures.

Viral Infectivity in Patients Undergoing Tracheotomy With COVID-19: A Preliminary Study

Objective

To establish the presence of live virus and its association with polymerase chain reaction (PCR) positivity and antibody status in patients with COVID-19 undergoing tracheotomy.

Study Design

Prospective observational study.

Setting

Single institution across 3 hospital sites during the first wave of the COVID-19 pandemic.

Methods

Patients who were intubated for respiratory wean tracheotomy underwent SARS-CoV-2 PCR nasal, throat, and endotracheal tube swabs at the time of the procedure. These were assessed via quantitative real-time reverse transcription PCR. The tracheal tissue excised during the tracheotomy was cultured for SARS-CoV-2 with Vero E6 and Caco2 cells. Serum was assessed for antibody titers against SARS-CoV-2 via neutralization assays.

Results

Thirty-seven patients were included in this study. The mean number of days intubated prior to undergoing surgical tracheotomy was 27.8. At the time of the surgical tracheotomy, PCR swab testing yielded 8 positive results, but none of the 35 individuals who underwent tissue culture were positive for SARS-CoV-2. All 18 patients who had serum sampling demonstrated neutralization antibodies, with a minimum titer of 1:80.

Conclusion

In our series, irrespective of positive PCR swab, the likelihood of infectivity during tracheotomy remains low given negative tracheal tissue cultures. While our results do not undermine national and international guidance on tracheotomy after day 10 of intubation, given the length of time to procedure in our data, infectivity at 10 days cannot be excluded. We do however suggest that a preoperative negative PCR swab not be a prerequisite and that antibody titer levels may serve as a useful adjunct for assessment of infectivity.

Literature Review: Occupational Safety and Health Risk Factors of Healthcare Workers during COVID-19 Pandemic

Introduction: The pandemic of COVID-19 has major effects, particularly on hospitals and health workers. At the beginning of March, more than 3,300 health workers have beencontracted with COVID-19 as reported by China's National Health Commission. Twenty percent of healthcare workers in Italy have also also infected and some died. To minimize the risk of transmission to health workers, knowledge of the risk factors that influence the transmission is needed. Thus, this study aims to determine risk factors related to occupational safety and health for healthcare workers during the COVID-19 pandemic. Methods: The literature was searched on Pubmed, Google Scholar, WHO, and the Ministry of Health instruments were implemented. 8 relevant studies were reviewed. Results: According to the analysis results of several studies, the use of PPE that is less consistent and not suitable with the risk of exposure will increase the risk of infection. The risk of infection is also increased by poor hand hygiene. According to the Kaplan-Meier curve, the working duration of ≥ 15 hours will increase the risk of infection. The risk of infection also exists for health workers who carry out risky procedures that generate airborne particles such as resuscitation, as well as environmental factors such as negative pressure rooms and traffic control bundling. Conclusion: Risk factors related to occupational health and safety during this COVID-19 pandemic for healthcare staff are: compliance with the use of PPE, hand hygiene, working hours duration, risky procedures, and environmental factors.Keywords: healthcare workers, occupational safety, COVID-19, personal protective equipment

A Novel Cough Simulation Device for Education of Risk Mitigation Techniques During Aerosol-Generating Medical Procedures

The COVID-19 pandemic has drawn attention to aerosol-generating medical procedures (AGMPs) in health care environments as a potential mode of transmission. Many organizations and institutions have published AGMP safety guidelines, and several mention the use of simulation in informing their recommendations; however, current methods used to simulate aerosol generation are heterogenous. Creation of a high-fidelity, easily producible aerosol-generating cough simulator would meet a high-priority educational need across all medical specialties. In this communication, we describe the design, construction, and user study of a novel cough simulator, which demonstrates the utility of simulation in raising AGMP safety awareness for providers of all roles, specialties, and training levels.

Severe covid-19 pneumonia: pathogenesis and clinical management

Severe covid-19 pneumonia has posed critical challenges for the research and medical communities. Older age, male sex, and comorbidities increase the risk for severe disease. For people hospitalized with covid-19, 15-30% will go on to develop covid-19 associated acute respiratory distress syndrome (CARDS). Autopsy studies of patients who died of severe SARS CoV-2 infection reveal presence of diffuse alveolar damage consistent with ARDS but with a higher thrombus burden in pulmonary capillaries. When used appropriately, high flow nasal cannula (HFNC) may allow CARDS patients to avoid intubation, and does not increase risk for disease transmission. During invasive mechanical ventilation, low tidal volume ventilation and positive end expiratory pressure (PEEP) titration to optimize oxygenation are recommended. Dexamethasone treatment improves mortality for the treatment of severe and critical covid-19, while remdesivir may have modest benefit in time to recovery in patients with severe disease but shows no statistically significant benefit in mortality or other clinical outcomes. Covid-19 survivors, especially patients with ARDS, are at high risk for long term physical and mental impairments, and an interdisciplinary approach is essential for critical illness recovery.

Tracheostomies after SARS-CoV-2 intubation, performed by academic otorhinolaryngologists in the Paris area of France: Preliminary results

Objective

To analyse tracheostomies after intubation for SARS-Cov-2 infection performed by otorhinolaryngologists in 7 university hospitals in the Paris area of France during the month March 24 to April 23, 2020.

Material and methods

A multicentre retrospective observational study included 59 consecutive patients. The main goals were to evaluate the number, characteristics and practical conditions of tracheostomies, and the COVID-19 status of the otorhinolaryngologists. Secondary goals were to analyse tracheostomy time, decannulation rate, immediate postoperative complications and laryngotracheal axis status.

Results

Tracheostomy indications were for ventilatory weaning and extubation failure in 86% and 14% of cases, respectively. The technique was surgical, percutaneous or hybrid in 91.5%, 3.4% and 5.1% of cases, respectively. None of the operators developed symptoms consistent with COVID-19. Postoperative complications occurred in 15% of cases, with no significant difference between surgical and percutaneous/hybrid techniques (P = 0.33), although no complications occurred after percutaneous or hybrid tracheostomies. No procedures or complications resulted in death. The decannulation rate was 74.5% with a mean tracheostomy time of 20 ± 12 days. In 55% of the patients evaluated by flexible endoscopy after decannulation, a laryngeal abnormality was found. On univariate analysis, no clinical features had a significant influence on tracheostomy time, decannulation rate or occurrence of laryngeal lesions.

Conclusion

The main findings of the present retrospective study were: absence of contamination of the surgeons, heterogeneity of practices between centres, a high rate of complications and laryngeal lesions whatever the technique, and the specificities of the patients.

Risk of Airborne COVID-19 Transmission While Performing Humphrey Visual Field Testing

PRECIS

Designing and demonstrating an experiment that shows the risk of airborne transmission of COVID-19 between patients having visual fields analyzed is low.

PURPOSE

The aim was to investigate the possibility of airborne transmission of COVID-19 during Humphrey visual field testing in a real-world scenario.

METHODS

A particle counter was placed within the bowl of Humphrey visual field analyzer (HFA) before and after turning on the machine to ascertain the effect of the air current produced by the ventilation system on aerosols. A second experiment was run where the particle counter was placed in the bowl and recorded particulates, in the air, as a 24-2 SITA standard was performed by a mock patient and then again immediately after the patient had moved away. We measured aerosol particle counts sized ≤0.3 μm, >0.3≤0.5 μm, >0.5≤1 μm, >1≤2.5 μm, >2.5≤5 μm, and >5≤10 μm.

RESULTS

Particulates of all sizes were shown to be significantly reduced within the bowl after turning the machine on, demonstrating that the air current produced by the HFA pushes air out of the bowl and it cannot stagnate. There was no significant difference in measurement of aerosol while there was a patient performing the test and immediately after they had moved away, suggesting that aerosols breathed out by the patient are not able to remain in suspension in the bowl because of the ventilation current.

CONCLUSION

There is no significant difference between aerosol count in the bowl of a HFA before, during and after testing. This suggests the risk of airborne transmission of COVID-19 is low between subsequent patients. This is in keeping with manufacturer's guidance on Humphrey visual field testing.

Percutaneous and Open Tracheostomy in Patients with COVID-19: Comparison and Outcomes of an Institutional Series in New York City

OBJECTIVE

The aim of this study was to report the safety, efficacy, and early results of tracheostomy in patients with COVID-19 and determine whether differences exist between percutaneous and open methods.

SUMMARY BACKGROUND DATA

Prolonged respiratory failure is common in symptomatic patients with COVID-19, the disease process caused by infection with the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Tracheostomy, although posing potential risk to the operative team and other healthcare workers, may be beneficial for safe weaning of sedation and ventilator support. However, short- and long-term outcomes remain largely unknown.

METHODS

A prospectively collected database of patients with COVID-19 undergoing tracheostomy at a major medical center in New York City between April 4 and April 30, 2020 was reviewed. The primary endpoint was need for continued mechanical ventilation. Secondary outcomes included complication rates, sedation weaning, and need for intensive care unit (ICU) level of care. Patient characteristics, perioperative conditions, and outcomes between percutaneous and open groups were analyzed.

RESULTS

During the study period, 67 consecutive patients underwent tracheostomy, including 48 males and 19 females with a median age of 66 years [interquartile range (IQR) 52-72]. Two surgeons alternated techniques, with 35 tracheostomies performed percutaneously and 32 via an open approach. The median time from intubation to tracheostomy was 23 days (IQR 20-26). At a median follow-up of 26 days, 52 patients (78%) no longer required mechanical ventilation and 58 patients (87%) were off continuous sedation. Five patients (7.5%) died of systemic causes. There were 11 total complications (16%) in 10 patients, most of which involved minor bleeding. There were no significant differences in outcomes between percutaneous and open methods.

CONCLUSIONS

Tracheostomy under apneic conditions by either percutaneous or open technique can be safely performed in patients with respiratory failure due to COVID-19. Tracheostomy facilitated weaning from continuous intravenous sedation and mechanical ventilation. Continued follow-up of these patients to ascertain long-term outcome data is ongoing.

Rewriting the playbook: infection prevention practices to mitigate nosocomial severe acute respiratory syndrome coronavirus 2 transmission

PURPOSE OF REVIEW

Given the limited evidence and experience with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), this novel pathogen has challenged the field of infection prevention. Despite uncertainty, infection prevention principles and experience with similar diseases have helped guide how to best protect providers and patients against disease acquisition.

RECENT FINDINGS

Guidance to date has relied on data from SARS-CoV-1 and MERS-CoV to guide practices on patient isolation and personal protective equipment (PPE) use. Although a face mask and eye protection are likely adequate for most clinical scenarios, published guidelines for PPE can be confusing and conflicting. Consensus for what constitutes a high-risk aerosol-generating procedure (AGP) is lacking, but most agree providers performing procedures such as bronchoscopy, intubation, and cardiopulmonary resuscitation would likely benefit from the use of an N95 respirator and eye protection.

SUMMARY

Needed research to elucidate the predominant SARS-CoV-2 mode of transmission is not likely to be completed in the immediate future. Recommendations for PPE to mitigate procedure-associated risk remain controversial. Nonetheless, implementation of existing measures based on basic infection prevention principles is likely to prevent transmission significantly.

Risk factors and protective measures for healthcare worker infection during highly infectious viral respiratory epidemics: a systematic review and meta-analysis

OBJECTIVE

To investigate risk factors for HCW infection in viral respiratory pandemics (SARS-CoV-2, MERS, SARS CoV-1, influenza A H1N1, influenza H5N1) and improve understanding of HCW risk management amidst the COVID-19 pandemic.

DESIGN

Systematic review and meta-analysis.

METHODS

MEDLINE, EMBASE, CINAHL, and Cochrane CENTRAL databases were searched from conception until July 2020 for studies comparing infected HCWs (cases) and non-infected HCWs (controls) and risk factors for infection. Outcomes included HCW types, infection prevention practices, and medical procedures. Pooled effect estimates with pathogen-specific stratified meta-analysis and inverse variance meta-regression analysis were completed. GRADE framework was used to rate certainty of evidence. PROSPERO (CRD42020176232) 6 April 2020.

RESULTS

Fifty-four comparative studies were included (n=191,004 HCWs). Compared to non-frontline HCWs, frontline HCWs were at increased infection risk (OR 1.66 95%CI 1.24 to 2.22) and greater for HCWs involved in endotracheal intubations (risk difference [95%CI]: 35.2% [21.4 to 47.9]). Use of gloves, gown, surgical mask, N95 respirator, face protection, and infection training were each strongly protective against infection. Meta-regression showed reduced infection risk in frontline HCWs working in facilities with infection designated wards (OR -1.04, 95%CI -1.53 to -0.33, p=0.004) and performing aerosol-generating medical procedures in designated centres (OR -1.30 95%CI -2.52 to -0.08; p=0.037).

CONCLUSIONS

During highly infectious respiratory pandemics, widely available protective measures such as use of gloves, gowns, and face masks are strongly protective against infection and should be instituted, preferably in dedicated settings, to protect frontline HCW during waves of respiratory virus pandemics.

Safety and Feasibility of a Novel Protocol for Percutaneous Dilatational Tracheostomy in Patients with Respiratory Failure due to COVID-19 Infection: A Single Center Experience

Introduction

The rapidly spreading Novel Coronavirus 2019 (COVID-19) appeared to be a highly transmissible pathogen in healthcare environments and had resulted in a significant number of patients with respiratory failure requiring tracheostomy, an aerosol-generating procedure that places healthcare workers at high risk of contracting the infection. Instead of deferring or delaying the procedure, we developed and implemented a novel percutaneous dilatational tracheostomy (PDT) protocol aimed at minimizing the risk of transmission while maintaining favorable procedural outcome. Patients and Methods. All patients who underwent PDT per novel protocol were included in the study. The key element of the protocol was the use of apnea during the critical part of the insertion and upon any opening of the ventilator circuit. This was coupled with the use of enhanced personnel protection equipment (PPE) with a powered air-purifying respirator (PAPR). The operators underwent antibody serology testing and were evaluated for COVID-19 symptoms two weeks from the last procedure included in the study.

Results

Between March 12th and June 30th, 2020, a total of 32 patients underwent PDT per novel protocol. The majority (80%) were positive for COVID-19 at the time of the procedure. The success rate was 94%. Only one patient developed minor self-limited bleeding. None of the proceduralists developed positive serology or any symptoms compatible with COVID-19 infection.

Conclusion

A novel protocol that uses periods of apnea during opening of the ventilator circuit along with PAPR-enhanced PPE for PDT on COVID-19 patients appears to be effective and safe for patients and healthcare providers.

Management of tracheostomy in COVID-19 patients: The Japanese experience

Objective

Involvement in the tracheostomy procedure for COVID-19 patients can lead to a feeling of fear in medical staff. To address concerns over infection, we gathered and analyzed experiences with tracheostomy in the COVID-19 patient population from all over Japan.

Methods

The data for health-care workers involved in tracheostomies for COVID-19-infected patients were gathered from academic medical centers or their affiliated hospitals from all over Japan.

Results

Tracheostomies have been performed in 35 COVID-19 patients with a total of 91 surgeons, 49 anesthesiologists, and 49 surgical staff members involved. Twenty-eight (80%) patients underwent surgery more than 22 days after the development of COVID-19-related symptoms (11: 22–28 days and 17: ≥29 days). Thirty (85.7%) patients underwent surgery ≥ 15 days after intubation (14: 15–21 days, 6: 22–28 days, and 10: ≥29 days). Among the total of 189 health-care workers involved in the tracheostomy procedures, 25 used a powered air-purifying respirator (PAPR) and 164 used a N95 mask and eye protection. As a result, no transmission to staff occurred during the 2 weeks of follow-up after surgery.

Conclusion

No one involved in tracheostomy procedures were found to have been infected with COVID-19 in this Japanese study. The reason is thought to be that the timing of the surgery was quite late after the infections, and the surgery was performed using appropriate PPE and surgical procedure. The indications for and timing of tracheostomy for severe COVID-19 patients should be decided through multidisciplinary discussion.

A Comprehensive Review of Coronavirus Disease 2019: Epidemiology, Transmission, Risk Factors, and International Responses

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has caused a worldwide pandemic. The first reports of patients with COVID-19 were provided to World Health Organization on December 21, 2019 and were presumably associated with seafood markets in Wuhan, China. As of October 25, 2020, more than 42 million cases have been confirmed worldwide, with more than 1.1 million deaths. Asymptomatic transmission contributes significantly to transmission, and clinical features are non-specific to the disease. Thus, the diagnosis of COVID-19 requires specific viral RNA testing. The disease demonstrates extensive human-to-human transmissibility and has infected healthcare workers at high rates. Clinical awareness of the epidemiology and the risk factors for nosocomial transmission of COVID-19 is essential to preventing infection. Moreover, effective control measures should be further identified by comprehensive evaluation of hospital and community responses. In this review, we provide a comprehensive update on the epidemiology, presentation, transmission, risk factors, and public health measures associated with COVID-19. We also review past insights from previous coronavirus epidemics [i.e., severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS)] to suggest measures to reduce transmission.

Respiratory Protective Equipment for Healthcare Providers During Coronavirus Pandemic: "Nec Temere, Nec Timide"

In otorhinolaryngology-head and neck surgery, there are several routine and surgical procedures applied to the upper airway that generate droplets and/or aerosols. Therefore, otorhinolaryngology-head and neck surgeons are at higher risk of being exposed to viral content. The COVID-19 pandemic has shaken the world with approximately 30 million affected cases and more than 900.000 deaths officially reported in more than 200 countries/regions from March 11^th, 2020 to date (September 12^th, 2020). All healthcare providers working at the frontlines of the fight against the COVID-19 are at risk of contracting the virus. In this review, we discuss the efficacy of the different types of respiratory protective equipment and remind about the surgery-based respiratory protection strategies in otorhinolaryngology and head and neck surgeries in the light of the latest literature.

Severe acute respiratory syndrome coronavirus 2 infection risk during elective peri-operative care: a narrative review

The protection of healthcare workers from the risk of nosocomial severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is a paramount concern. SARS-CoV-2 is likely to remain endemic and measures to protect healthcare workers against nosocomial infection will need to be maintained. This review aims to inform the assessment and management of the risk of SARS-CoV-2 transmission to healthcare workers involved in elective peri-operative care. In the absence of data specifically related to the risk of SARS-CoV-2 transmission in the peri-operative setting, we explore the evidence-base that exists regarding modes of viral transmission, historical evidence for the risk associated with aerosol-generating procedures and contemporaneous data from the COVID-19 pandemic. We identify a significant lack of data regarding the risk of transmission in the management of elective surgical patients, highlighting the urgent need for further research.

Personal protective equipment (PPE) and infection among healthcare workers - What is the evidence?

BACKGROUND

The worldwide outbreak of coronavirus disease-19 (COVID-19) has already put healthcare workers (HCWs) at a high risk of infection. The question of how to give HCWs the best protection against infection is a priority.

METHODS

We searched systematic reviews and original studies in Medline (via Ovid) and Chinese Wan Fang digital database from inception to May, 2020, using terms 'coronavirus', 'health personnel', and 'personal protective equipment' to find evidence about the use of full-body PPEs and other PPEs by HCW exposed highly infectious diseases.

RESULTS

Covering more of the body could provide better protection for HCWs. Of importance, it is not just the provision of PPE but the skills in donning and doffing of PPE that are important, this being a key time for potential transmission of pathogen to the HCW and in due time from them to others. In relation to face masks, the evidence indicates that a higher-level specification of face masks and respirators (such as N95) seems to be essential to protect HCWs from coronavirus infection. In community setting, the use of masks in the case of well individuals could be beneficial. Evidence specifically around PPE and protection from the COVID-19 virus is limited.

CONCLUSION

Covering more of the body, and a higher-level specification of masks and respirators could provide better protection for HCWs. Community mask usecould be beneficial. High quality studies still need to examine the protection of PPE against COVID-19.

Use of N95, Surgical, and Cloth Masks to Prevent COVID-19 in Health Care and Community Settings: Living Practice Points From the American College of Physicians (Version 1)

Controversy exists around the appropriate types of masks and the situations in which they should be used in community and health care settings for the prevention of SARS-CoV-2 infection. In this article, the American College of Physicians (ACP) provides recommendations based on the best available evidence through 14 April 2020 on the effectiveness of N95 respirators, surgical masks, and cloth masks in reducing transmission of infection. The ACP plans periodic updates of these recommendations on the basis of ongoing surveillance of the literature for 1 year from the initial search date.

Timing, Complications, and Safety of Tracheotomy in Critically Ill Patients With COVID-19

IMPORTANCE

The current coronavirus disease 2019 (COVID-19) pandemic has led to unprecedented needs for invasive ventilation, with 10% to 15% of intubated patients subsequently requiring tracheotomy.

OBJECTIVE

To assess the complications, safety, and timing of tracheotomy performed for critically ill patients with COVID-19.

DESIGN, SETTING, AND PARTICIPANTS

This prospective cohort study assessed consecutive patients admitted to the intensive care unit (ICU) who had COVID-19 that required tracheotomy. Patients were recruited from March 16 to April 10, 2020, at a tertiary referral center.

EXPOSURES

A surgical tracheotomy was performed for all patients following recommended criteria for use of personal protective equipment (PPE).

MAIN OUTCOMES AND MEASURES

The number of subthyroid operations, the tracheal entrance protocol, and use of PPE. Infections among the surgeons were monitored weekly by reverse-transcriptase polymerase chain reaction of nasopharyngeal swab samples. Short-term complications, weaning, and the association of timing of tracheotomy (early [≤10 days] vs late [>10 days]) with total required days of invasive ventilation were assessed.

RESULTS

A total of 50 patients (mean [SD] age, 63.8 [9.2] years; 33 [66%] male) participated in the study. All tracheotomies were performed at the bedside. The median time from intubation to tracheotomy was 9 days (interquartile range, 2-24 days). A subthyroid approach was completed for 46 patients (92%), and the tracheal protocol was adequately achieved for 40 patients (80%). Adequate PPE was used, with no infection among surgeons identified 4 weeks after the last tracheotomy. Postoperative complications were rare, with minor bleeding (in 6 patients [12%]) being the most common complication. The successful weaning rate was higher in the early tracheotomy group than in the late tracheotomy group (adjusted hazard ratio, 2.55; 95% CI, 0.96-6.75), but the difference was not statistically significant. There was less time of invasive mechanical ventilatory support with early tracheotomy compared with late tracheotomy (mean [SD], 18 [5.4] vs 22.3 [5.7] days). The reduction of invasive ventilatory support was achieved at the expense of the pretracheotomy period.

CONCLUSIONS AND RELEVANCE

In this cohort study, with the use of a standardized protocol aimed at minimizing COVID-19 risks, bedside open tracheotomy was a safe procedure for patients and surgeons, with minimal complications. Timing of tracheotomy may be important in reducing time of invasive mechanical ventilation, with potential implications to intensive care unit availability during the COVID-19 pandemic.

Masks for Prevention of Respiratory Virus Infections, Including SARS-CoV-2, in Health Care and Community Settings : A Living Rapid Review

BACKGROUND

Recommendations on masks for preventing coronavirus disease 2019 (COVID-19) vary.

PURPOSE

To examine the effectiveness of N95, surgical, and cloth masks in community and health care settings for preventing respiratory virus infections, and effects of reuse or extended use of N95 masks.

DATA SOURCES

Multiple electronic databases, including the World Health Organization COVID-19 database and medRxiv preprint server (2003 through 14 April 2020; surveillance through 2 June 2020), and reference lists.

STUDY SELECTION

Randomized trials of masks and risk for respiratory virus infection, including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and observational studies of mask use and coronavirus infection risk were included. New evidence will be incorporated by using living review methods.

DATA EXTRACTION

One reviewer abstracted data and assessed methodological limitations; a second reviewer provided verification.

DATA SYNTHESIS

39 studies (18 randomized controlled trials and 21 observational studies; 33 867 participants) were included. No study evaluated reuse or extended use of N95 masks. Evidence on SARS-CoV-2 was limited to 2 observational studies with serious limitations. Community mask use was possibly associated with decreased risk for SARS-CoV-1 infection in observational studies. In high- or moderate-risk health care settings, observational studies found that risk for infection with SARS-CoV-1 and Middle East respiratory syndrome coronavirus probably decreased with mask use versus nonuse and possibly decreased with N95 versus surgical mask use. Randomized trials in community settings found possibly no difference between N95 versus surgical masks and probably no difference between surgical versus no mask in risk for influenza or influenza-like illness, but compliance was low. In health care settings, N95 and surgical masks were probably associated with similar risks for influenza-like illness and laboratory-confirmed viral infection; clinical respiratory illness had inconsistency. Bothersome symptoms were common.

LIMITATIONS

There were few SARS-CoV-2 studies, observational studies have methodological limitations, and the review was done by using streamlined methods.

CONCLUSION

Evidence on mask effectiveness for respiratory infection prevention is stronger in health care than community settings. N95 respirators might reduce SARS-CoV-1 risk versus surgical masks in health care settings, but applicability to SARS-CoV-2 is uncertain.

PRIMARY FUNDING SOURCE

Agency for Healthcare Research and Quality.

Epidemiology of and Risk Factors for COVID-19 Infection among Health Care Workers: A Multi-Centre Comparative Study

Healthcare workers (HCWs) worldwide are putting themselves at high risks of coronavirus disease 2019 (COVID-19) by treating a large number of patients while lacking protective equipment. We aim to provide a scientific basis for preventing and controlling the COVID-19 infection among HCWs. We used data on COVID-19 cases in the city of Wuhan to compare epidemiological characteristics between HCWs and non-HCWs and explored the risk factors for infection and deterioration among HCWs based on hospital settings. The attack rate (AR) of HCWs in the hospital can reach up to 11.9% in Wuhan. The time interval from symptom onset to diagnosis in HCWs and non-HCWs dropped rapidly over time. From mid-January, the median time interval of HCW cases was significantly shorter than in non-HCW cases. Cases of HCWs and non-HCWs both clustered in northwestern urban districts rather than in rural districts. HCWs working in county-level hospitals in high-risk areas were more vulnerable to COVID-19. HCW cases working in general, ophthalmology, and respiratory departments were prone to deteriorate compared with cases working in the infection department. The AR of COVID-19 in HCWs are higher than in non-HCWs. Multiple factors in hospital settings may play important roles in the transmission of COVID-19. Effective measures should be enhanced to prevent HCWs from COVID-19 infection.

Perioperative Cancer Care in the Context of Limited Resources during the COVID-19 Pandemic: Brazilian Society of Surgical Oncology Recommendations

BACKGROUND

As the COVID-19 pandemic moves from rich to poor nations, the healthcare systems of developing countries have to deal with this extra burden. As cancer care cannot stop and surgery is the main mechanism for cure and palliation, it is important to provide safe and rational access to cancer surgery during the COVID-19 pandemic.

METHODS

From April 1st to May 1st, the committee of the Brazilian Society of Surgical Oncology (BSSO) was responsible for reviewing the literature and writing recommendations for perioperative cancer care in the context of limited resources during the pandemic. The recommendations were submitted to the BSSO board of directors. The orientations that were not consensual were removed and the suggestions were added to the text. From May 15 to 30th, the committee revised the recommendations, aligned them with the objectives of the work and standardize the text.

DISCUSSION

The rational use of resources to reduce the risk of surgical cancer patients being operated on during the incubation period of a corona virus infection is important in this context. Prevalence of corona virus in the region, the need for surgery, surgical complexity, patient age and comorbidities, and availability of corona virus testing are central aspects in this matter and are discussed.

CONCLUSIONS

We present a protocol, focused on the patients' outcomes, for safe and rational use of resources to reduce the risk of surgical cancer patients being operated on during the virus incubation period, in the context of areas with limited resources.

Potential of Ocular Transmission of SARS-CoV-2: A Review

PURPOSE OF REVIEW

to provide a prospective on the current mechanisms by which SARS-CoV-2 enters cells and replicates, and its implications for ocular transmission. The literature was analyzed to understand ocular transmission as well as molecular mechanisms by which SARS-CoV-2 enters cells and replicates. Analysis of gene expression profiles from available datasets, published immunohistochemistry, as well as current literature was reviewed, to assess the likelihood that ocular inoculation of SARS-CoV-2 results in systemic infection.

RECENT FINDINGS

The ocular surface and retina have the necessary proteins, Transmembrane Serine Protease 2 (TMPRSS2), CD147, Angiotensin-Converting Enzyme 2 (ACE2) and Cathepsin L (CTSL) necessary to be infected with SARS-CoV-2. In addition to direct ocular infection, virus carried by tears through the nasolacrimal duct to nasal epithelium represent a means of ocular inoculation.

SUMMARY

There is evidence that SARS-CoV-2 may either directly infect cells on the ocular surface, or virus can be carried by tears through the nasolacrimal duct to infect the nasal or gastrointestinal epithelium.

Oxygen Therapy and Risk of Infection for Health Care Workers Caring for Patients With Viral Severe Acute Respiratory Infection: A Systematic Review and Meta-analysis

Study objective

To synthesize the evidence regarding the infection risk associated with different modalities of oxygen therapy used in treating patients with severe acute respiratory infection. Health care workers face significant risk of infection when treating patients with a viral severe acute respiratory infection. To ensure health care worker safety and limit nosocomial transmission of such infection, it is crucial to synthesize the evidence regarding the infection risk associated with different modalities of oxygen therapy used in treating patients with severe acute respiratory infection.

Methods

MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials were searched from January 1, 2000, to April 1, 2020, for studies describing the risk of infection associated with the modalities of oxygen therapy used for patients with severe acute respiratory infection. The study selection, data extraction, and quality assessment were performed by independent reviewers. The primary outcome measure was the infection of health care workers with a severe acute respiratory infection. Random-effect models were used to synthesize the extracted data.

Results

Of 22,123 citations, 50 studies were eligible for qualitative synthesis and 16 for meta-analysis. Globally, the quality of the included studies provided a very low certainty of evidence. Being exposed or performing an intubation (odds ratio 6.48; 95% confidence interval 2.90 to 14.44), bag-valve-mask ventilation (odds ratio 2.70; 95% confidence interval 1.31 to 5.36), and noninvasive ventilation (odds ratio 3.96; 95% confidence interval 2.12 to 7.40) were associated with an increased risk of infection. All modalities of oxygen therapy generate air dispersion.

Conclusion

Most modalities of oxygen therapy are associated with an increased risk of infection and none have been demonstrated as safe. The lowest flow of oxygen should be used to maintain an adequate oxygen saturation for patients with severe acute respiratory infection, and manipulation of oxygen delivery equipment should be minimized.

Ventilation Techniques and Risk for Transmission of Coronavirus Disease, Including COVID-19: A Living Systematic Review of Multiple Streams of Evidence

BACKGROUND

Mechanical ventilation is used to treat respiratory failure in coronavirus disease 2019 (COVID-19).

PURPOSE

To review multiple streams of evidence regarding the benefits and harms of ventilation techniques for coronavirus infections, including that causing COVID-19.

DATA SOURCES

21 standard, World Health Organization-specific and COVID-19-specific databases, without language restrictions, until 1 May 2020.

STUDY SELECTION

Studies of any design and language comparing different oxygenation approaches in patients with coronavirus infections, including severe acute respiratory syndrome (SARS) or Middle East respiratory syndrome (MERS), or with hypoxemic respiratory failure. Animal, mechanistic, laboratory, and preclinical evidence was gathered regarding aerosol dispersion of coronavirus. Studies evaluating risk for virus transmission to health care workers from aerosol-generating procedures (AGPs) were included.

DATA EXTRACTION

Independent and duplicate screening, data abstraction, and risk-of-bias assessment (GRADE for certainty of evidence and AMSTAR 2 for included systematic reviews).

DATA SYNTHESIS

123 studies were eligible (45 on COVID-19, 70 on SARS, 8 on MERS), but only 5 studies (1 on COVID-19, 3 on SARS, 1 on MERS) adjusted for important confounders. A study in hospitalized patients with COVID-19 reported slightly higher mortality with noninvasive ventilation (NIV) than with invasive mechanical ventilation (IMV), but 2 opposing studies, 1 in patients with MERS and 1 in patients with SARS, suggest a reduction in mortality with NIV (very-low-certainty evidence). Two studies in patients with SARS report a reduction in mortality with NIV compared with no mechanical ventilation (low-certainty evidence). Two systematic reviews suggest a large reduction in mortality with NIV compared with conventional oxygen therapy. Other included studies suggest increased odds of transmission from AGPs.

LIMITATION

Direct studies in COVID-19 are limited and poorly reported.

CONCLUSION

Indirect and low-certainty evidence suggests that use of NIV, similar to IMV, probably reduces mortality but may increase the risk for transmission of COVID-19 to health care workers.

PRIMARY FUNDING SOURCE

World Health Organization. (PROSPERO: CRD42020178187).

A detailed report on the measures taken in the Department of Conservative Dentistry and Periodontology in Munich at the beginning of the COVID-19 outbreak

OBJECTIVES

The corona disease (COVID-19) is developing into one of the greatest challenges for healthcare professionals around the world. In this article, we report the detailed actions taken in the Department of Conservative Dentistry and Periodontology, University Hospital, Ludwig-Maximilians-University (LMU), Munich, Germany, during the early phase of the COVID-19 pandemic.

MATERIAL AND METHODS

After a joint on-site inspection of the dental clinic with the Department of Clinical Microbiology and Hospital Hygiene, existing clinical and hygiene protocols were adapted for COVID-19 patients.

RESULTS

A comprehensive summary of the preparation of the facilities as well as pre- treatment, treatment and posttreatment protocols are described and arising problems are being discussed.

CONCLUSIONS

The importance of rigorous hygiene and treatment protocols as well as a sufficient supply of PPE for dental offices and hospitals is highlighted. The measures reported may be subject to change due to the dynamics of the pandemic.

CLINICAL RELEVANCE

The modes of transmission of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) (e.g., droplets, aerosols, and fomites) can pose a risk for dental healthcare professionals and patients alike. The presented measures may guide dental faculties and dental practices during the early stage of the COVID-19 crisis.

Epidemiology of and Risk Factors for Coronavirus Infection in Health Care Workers: A Living Rapid Review

BACKGROUND

Health care workers (HCWs) are at risk for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection.

PURPOSE

To examine the burden of SARS-CoV-2, SARS-CoV-1, and Middle East respiratory syndrome (MERS)-CoV on HCWs and risk factors for infection, using rapid and living review methods.

DATA SOURCES

Multiple electronic databases, including the WHO database of publications on coronavirus disease and the medRxiv preprint server (2003 through 27 March 2020, with ongoing surveillance through 24 April 2020), and reference lists.

STUDY SELECTION

Studies published in any language reporting incidence of or outcomes associated with coronavirus infections in HCWs and studies on the association between risk factors (demographic characteristics, role, exposures, environmental and administrative factors, and personal protective equipment [PPE] use) and HCW infections. New evidence will be incorporated on an ongoing basis by using living review methods.

DATA EXTRACTION

One reviewer abstracted data and assessed methodological limitations; verification was done by a second reviewer.

DATA SYNTHESIS

64 studies met inclusion criteria; 43 studies addressed burden of HCW infections (15 on SARS-CoV-2), and 34 studies addressed risk factors (3 on SARS-CoV-2). Health care workers accounted for a significant proportion of coronavirus infections and may experience particularly high infection incidence after unprotected exposures. Illness severity was lower than in non-HCWs. Depression, anxiety, and psychological distress were common in HCWs during the coronavirus disease 2019 outbreak. The strongest evidence on risk factors was on PPE use and decreased infection risk. The association was most consistent for masks but was also observed for gloves, gowns, eye protection, and handwashing; evidence suggested a dose-response relationship. No study evaluated PPE reuse. Certain exposures (such as involvement in intubations, direct patient contact, or contact with bodily secretions) were associated with increased infection risk. Infection control training was associated with decreased risk.

LIMITATION

There were few studies on risk factors for SARS-CoV-2, the studies had methodological limitations, and streamlined rapid review methods were used.

CONCLUSION

Health care workers experience significant burdens from coronavirus infections, including SARS-CoV-2. Use of PPE and infection control training are associated with decreased infection risk, and certain exposures are associated with increased risk.

PRIMARY FUNDING SOURCE

World Health Organization.

Personnel protection strategy for healthcare workers in Wuhan during the COVID-19 epidemic

Objective

To identify the effectiveness of a personnel protection strategy in protection of healthcare workers from SARS-CoV-2 infection.

Design

During the COVID-19 pandemic, 943 healthcare staff sent from Guangzhou to Wuhan to care for patients with suspected/confirmed COVID-19 received infection precaution training before their mission and were equipped with Level 2/3 personal protective equipment (PPE), in accordance with guidelines from the National Health Commission of China. We conducted a serological survey on the cumulative attack rate of SARS-CoV-2 among the healthcare workers sent to Wuhan and compared the seropositive rate to that in local healthcare workers from Wuhan and Jingzhou.

Results

Serial tests for SARS-CoV-2 RNA and tests for SARS-CoV-2 immunoglobulin M and G after the 6-8 week mission revealed a zero cumulative attack rate. Among the local healthcare workers in Wuhan and Jingzhou of Hubei Province, 2.5% (113 out of 4495) and 0.32% (10 out of 3091) had RT-PCR confirmed COVID-19, respectively. The seropositivity for SARS-CoV-2 antibodies (IgG, IgM, or both IgG/IgM positive) was 3.4% (53 out of 1571) in local healthcare workers from Wuhan with Level 2/3 PPE working in isolation areas and 5.4% (126 out of 2336) in healthcare staff with Level 1 PPE working in non-isolation medical areas, respectively.

Conclusions and relevance

Our study confirmed that adequate training/PPE can protect medical personnel against SARS-CoV-2.

Physical distancing, face masks, and eye protection to prevent person-to-person transmission of SARS-CoV-2 and COVID-19: a systematic review and meta-analysis

BACKGROUND

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes COVID-19 and is spread person-to-person through close contact. We aimed to investigate the effects of physical distance, face masks, and eye protection on virus transmission in health-care and non-health-care (eg, community) settings.

METHODS

We did a systematic review and meta-analysis to investigate the optimum distance for avoiding person-to-person virus transmission and to assess the use of face masks and eye protection to prevent transmission of viruses. We obtained data for SARS-CoV-2 and the betacoronaviruses that cause severe acute respiratory syndrome, and Middle East respiratory syndrome from 21 standard WHO-specific and COVID-19-specific sources. We searched these data sources from database inception to May 3, 2020, with no restriction by language, for comparative studies and for contextual factors of acceptability, feasibility, resource use, and equity. We screened records, extracted data, and assessed risk of bias in duplicate. We did frequentist and Bayesian meta-analyses and random-effects meta-regressions. We rated the certainty of evidence according to Cochrane methods and the GRADE approach. This study is registered with PROSPERO, CRD42020177047.

FINDINGS

Our search identified 172 observational studies across 16 countries and six continents, with no randomised controlled trials and 44 relevant comparative studies in health-care and non-health-care settings (n=25 697 patients). Transmission of viruses was lower with physical distancing of 1 m or more, compared with a distance of less than 1 m (n=10 736, pooled adjusted odds ratio [aOR] 0·18, 95% CI 0·09 to 0·38; risk difference [RD] -10·2%, 95% CI -11·5 to -7·5; moderate certainty); protection was increased as distance was lengthened (change in relative risk [RR] 2·02 per m; pinteraction=0·041; moderate certainty). Face mask use could result in a large reduction in risk of infection (n=2647; aOR 0·15, 95% CI 0·07 to 0·34, RD -14·3%, -15·9 to -10·7; low certainty), with stronger associations with N95 or similar respirators compared with disposable surgical masks or similar (eg, reusable 12-16-layer cotton masks; pinteraction=0·090; posterior probability >95%, low certainty). Eye protection also was associated with less infection (n=3713; aOR 0·22, 95% CI 0·12 to 0·39, RD -10·6%, 95% CI -12·5 to -7·7; low certainty). Unadjusted studies and subgroup and sensitivity analyses showed similar findings.

INTERPRETATION

The findings of this systematic review and meta-analysis support physical distancing of 1 m or more and provide quantitative estimates for models and contact tracing to inform policy. Optimum use of face masks, respirators, and eye protection in public and health-care settings should be informed by these findings and contextual factors. Robust randomised trials are needed to better inform the evidence for these interventions, but this systematic appraisal of currently best available evidence might inform interim guidance.

FUNDING

World Health Organization.

Physical distancing, face masks, and eye protection to prevent person-to-person transmission of SARS-CoV-2 and COVID-19: a systematic review and meta-analysis

BACKGROUND

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes COVID-19 and is spread person-to-person through close contact. We aimed to investigate the effects of physical distance, face masks, and eye protection on virus transmission in health-care and non-health-care (eg, community) settings.

METHODS

We did a systematic review and meta-analysis to investigate the optimum distance for avoiding person-to-person virus transmission and to assess the use of face masks and eye protection to prevent transmission of viruses. We obtained data for SARS-CoV-2 and the betacoronaviruses that cause severe acute respiratory syndrome, and Middle East respiratory syndrome from 21 standard WHO-specific and COVID-19-specific sources. We searched these data sources from database inception to May 3, 2020, with no restriction by language, for comparative studies and for contextual factors of acceptability, feasibility, resource use, and equity. We screened records, extracted data, and assessed risk of bias in duplicate. We did frequentist and Bayesian meta-analyses and random-effects meta-regressions. We rated the certainty of evidence according to Cochrane methods and the GRADE approach. This study is registered with PROSPERO, CRD42020177047.

FINDINGS

Our search identified 172 observational studies across 16 countries and six continents, with no randomised controlled trials and 44 relevant comparative studies in health-care and non-health-care settings (n=25 697 patients). Transmission of viruses was lower with physical distancing of 1 m or more, compared with a distance of less than 1 m (n=10 736, pooled adjusted odds ratio [aOR] 0·18, 95% CI 0·09 to 0·38; risk difference [RD] -10·2%, 95% CI -11·5 to -7·5; moderate certainty); protection was increased as distance was lengthened (change in relative risk [RR] 2·02 per m; p_interaction=0·041; moderate certainty). Face mask use could result in a large reduction in risk of infection (n=2647; aOR 0·15, 95% CI 0·07 to 0·34, RD -14·3%, -15·9 to -10·7; low certainty), with stronger associations with N95 or similar respirators compared with disposable surgical masks or similar (eg, reusable 12-16-layer cotton masks; p_interaction=0·090; posterior probability >95%, low certainty). Eye protection also was associated with less infection (n=3713; aOR 0·22, 95% CI 0·12 to 0·39, RD -10·6%, 95% CI -12·5 to -7·7; low certainty). Unadjusted studies and subgroup and sensitivity analyses showed similar findings.

INTERPRETATION

The findings of this systematic review and meta-analysis support physical distancing of 1 m or more and provide quantitative estimates for models and contact tracing to inform policy. Optimum use of face masks, respirators, and eye protection in public and health-care settings should be informed by these findings and contextual factors. Robust randomised trials are needed to better inform the evidence for these interventions, but this systematic appraisal of currently best available evidence might inform interim guidance.

FUNDING

World Health Organization.