Does an N95 mask reduce the risk of contracting viruses that cause respiratory disease better than a surgical mask?

Submitted by: ELee 65

No. While the bulk of the studies in this list for which we identified answers agrees with this conclusion, some studies came to different conclusions. We encourage you to consider each of the studies for yourself to understand why they differ. Note that while a minority of studies came to a contrary conclusion, one of these contrary studies has been critiqued, which may give you more confidence in our answer. (A link to the critique appears on the corresponding study summary below).
NOTE: New research on COVID-19 comes out nearly every day. The state of our knowledge may change quickly so take this answer with a grain of salt.
This short answer was generated by aggregating the answers that each of the 17 studies below gave to the question (as indicated by State of K members) and adjusting for source quality and other factors. If key studies are missing or the answers attributed to individual studies are incorrect, the above answer could be wrong. For medical questions, don't rely on the information here. Consult a medical professional.


Chart summary of 17 studies examining this question
Showing up to 10 at a time

All answers are assigned by State of K users. The label Couldn't Identify means that State of K was not able to determine whether a study answers the question "yes" or "no". This could be due to several factors. One possibility is that a study found some evidence to indicate that the answer to the question is "yes" and some evidence to indicate that the answer is "no". This often happens when a study uses two or more proxies to study the same phenomenon (i.e. firearm sales figures and self-reported firearm ownership rates as proxies for the prevalence of firearms) and the proxies yield different results when looking for correlations with another phenomenon (i.e. firearm-related deaths). Alternatively, the label may be applied if the phenomenon under study (i.e. whether breast milk improves cognitive function) is true for one group, but not another (i.e. true for girls, but not for boys). Yet another possibility is that a study found there was insufficient evidence to reach a conclusion regarding the question. Finally, the full text or abstract of a study may not have been written clearly or was inaccessible. This would make it difficult to determine how a study answered a question.

All labels of Literature Reviews and source quality are assigned by State of K. For academic journals, the label "Q[NUMBER]" is an indication of the quality of the publication. The "NUMBER" refer to the best quartile in which the journal appeared among all the subjects in which the journal was ranked by Scimago Institutions Rankings. For example, if a journal was ranked in the third quartile (Q3) in infectious diseases, but in the second quartile in Ebola studies (Q2), you would see "Q2". The best quartile is "Q1". Publications other than academic journals may be labeled as "Highly Regarded Sources". Government sources receive this label as do NGOs ranked by the TTCSP Global Go To Think Tank Index Reports. The information contained in a source that is labeled "highly regarded" or "Q1" is not necessarily more accurate than information contained in a source without that label, but these are rough guides to source quality.

Literature Reviews
Although we recommend you consider all of the studies below, we believe the following studies are literature reviews, which survey and evaluate many studies on this question:
Additional Recommended Studies Not in this List (yet)

QUESTIONS TO CONSIDER
Are cloth masks as effective as surgical masks at reducing the risk of contracting viruses that cause respiratory disease?
6 studies
Submitted by: MChoi 148

Do adults get sick from COVID-19 more often than children?
10 studies
Submitted by: JLjilijana 85

Do cloth masks reduce the risk of contracting viruses that cause respiratory disease?
5 studies
Submitted by: JAloni 111

Does air pollution accelerate the spread of COVID-19?
5 studies
Submitted by: JLjilijana 85

Does air pollution increase the severity of symptoms from COVID-19?
6 studies
Submitted by: KKrista 83

Does a surgical (non-N95) mask reduce the risk of contracting viruses that cause respiratory disease?
23 studies
Submitted by: ELee 65

Add question
What additional question do you want someone who searches for "Does an N95 mask reduce the risk of contracting viruses that cause respiratory disease better than a surgical mask" to consider?

SUMMARIES OF STUDIES
Total studies in list: 17
Sorted by publication year
1
Effectiveness of N95 respirators versus surgical masks against influenza: A systematic review and meta-analysis
"OBJECTIVE:Previous meta-analyses concluded that there was insufficient evidence to determine the effect of N95 respirators. We aimed to assess the effectiveness of N95 respirators versus surgical masks for prevention of influenza by collecting randomized controlled trials (RCTs).METHODS:We searched PubMed, EMbase and The Cochrane Library from the inception to January 27, 2020 to identify relevant systematic reviews. The RCTs included in systematic reviews were identified. Then we searched the latest published RCTs from the above three databases and searched ClinicalTrials.gov for unpublished RCTs. Two reviewers independently extracted the data and assessed risk of bias. Meta-analyses were conducted to calculate pooled estimates by using RevMan 5.3 software.RESULTS:A total of six RCTs involving 9 171 participants were included. There were no statistically significant differences in preventing laboratory-confirmed influenza (RR = 1.09, 95% CI 0.92-1.28, P > .05), laboratory-confirmed respiratory viral infections (RR = 0.89, 95% CI 0.70-1.11), laboratory-confirmed respiratory infection (RR = 0.74, 95% CI 0.42-1.29) and influenzalike illness (RR = 0.61, 95% CI 0.33-1.14) using N95 respirators and surgical masks. Meta-analysis indicated a protective effect of N95 respirators against laboratory-confirmed bacterial colonization (RR = 0.58, 95% CI 0.43-0.78).CONCLUSION:The use of N95 respirators compared with surgical masks is not associated with a lower risk of laboratory-confirmed influenza. It suggests that N95 respirators should not be recommended for general public and nonhigh-risk medical staff those are not in close contact with influenza patients or suspected patients."
AUTHORS
Liu L
Guo Q
Chen R
Hu T
Long Y
Cheng Y et al
PUBLISHED
2020 in Journal of Evidence-Based Medicine
High quality source
Literature Review
FUNDERS
National Natural Science Foundation of China
No
No
2
Association between 2019-nCoV transmission and N95 respirator use
"A randomized clinical trial has reported that the N95 respirators vs medical masks resulted in no significant difference in the incidence of laboratory confirmed influenza4. In our study, we observed that the N95 respirators, disinfection and hand washing appear to help reduce the infectious risk of 2019-nCoV in doctors and nurses. Interestingly, departments with a high proportion of male doctors seemed to have a higher risk of infection. Our results emphasize the need for strict occupational protection measures in fighting COVID-19."
AUTHORS
Zhenyu Pan
Zhenshun Cheng
Xinghuan Wang
PUBLISHED
2020 in Journal of Hospital Infection
High quality source
FUNDERS
Wuhan University
Couldn't Identify
Couldn't Identify
3
N95 respirators vs medical masks for preventing influenza among health care personnel: a randomized clinical trial
"IMPORTANCE:Clinical studies have been inconclusive about the effectiveness of N95 respirators and medical masks in preventing health care personnel (HCP) from acquiring workplace viral respiratory infections.OBJECTIVE:To compare the effect of N95 respirators vs medical masks for prevention of influenza and other viral respiratory infections among HCP.DESIGN, SETTING, AND PARTICIPANTS:A cluster randomized pragmatic effectiveness study conducted at 137 outpatient study sites at 7 US medical centers between September 2011 and May 2015, with final follow-up in June 2016. Each year for 4 years, during the 12-week period of peak viral respiratory illness, pairs of outpatient sites (clusters) within each center were matched and randomly assigned to the N95 respirator or medical mask groups.INTERVENTIONS:Overall, 1993 participants in 189 clusters were randomly assigned to wear N95 respirators (2512 HCP-seasons of observation) and 2058 in 191 clusters were randomly assigned to wear medical masks (2668 HCP-seasons) when near patients with respiratory illness.MAIN OUTCOMES AND MEASURES:The primary outcome was the incidence of laboratory-confirmed influenza. Secondary outcomes included incidence of acute respiratory illness, laboratory-detected respiratory infections, laboratory-confirmed respiratory illness, and influenzalike illness. Adherence to interventions was assessed.RESULTS:Among 2862 randomized participants (mean [SD] age, 43 [11.5] years; 2369 [82.8%]) women), 2371 completed the study and accounted for 5180 HCP-seasons. There were 207 laboratory-confirmed influenza infection events (8.2% of HCP-seasons) in the N95 respirator group and 193 (7.2% of HCP-seasons) in the medical mask group (difference, 1.0%, [95% CI, -0.5% to 2.5%]; P = .18) (adjusted odds ratio [OR], 1.18 [95% CI, 0.95-1.45]). There were 1556 acute respiratory illness events in the respirator group vs 1711 in the mask group (difference, -21.9 per 1000 HCP-seasons [95% CI, -48.2 to 4.4]; P = .10); 679 laboratory-detected respiratory infections in the respirator group vs 745 in the mask group (difference, -8.9 per 1000 HCP-seasons, [95% CI, -33.3 to 15.4]; P = .47); 371 laboratory-confirmed respiratory illness events in the respirator group vs 417 in the mask group (difference, -8.6 per 1000 HCP-seasons [95% CI, -28.2 to 10.9]; P = .39); and 128 influenzalike illness events in the respirator group vs 166 in the mask group (difference, -11.3 per 1000 HCP-seasons [95% CI, -23.8 to 1.3]; P = .08). In the respirator group, 89.4% of participants reported "always" or "sometimes" wearing their assigned devices vs 90.2% in the mask group.CONCLUSIONS AND RELEVANCE:Among outpatient health care personnel, N95 respirators vs medical masks as worn by participants in this trial resulted in no significant difference in the incidence of laboratory-confirmed influenza.TRIAL REGISTRATION:ClinicalTrials.gov Identifier: NCT01249625."
AUTHORS
Simberkoff MS
Radonovich LJ Jr
PUBLISHED
2019 in JAMA
High quality source
No
No
4
Effectiveness of masks and respirators against respiratory infections in healthcare workers: a systematic review and meta-analysis
"This systematic review and meta-analysis quantified the protective effect of facemasks and respirators against respiratory infections among healthcare workers. Relevant articles were retrieved from Pubmed, EMBASE, and Web of Science. Meta-analyses were conducted to calculate pooled estimates. Meta-analysis of randomized controlled trials (RCTs) indicated a protective effect of masks and respirators against clinical respiratory illness (CRI) (risk ratio [RR] = 0.59; 95% confidence interval [CI]:0.46-0.77) and influenza-like illness (ILI) (RR = 0.34; 95% CI:0.14-0.82). Compared to masks, N95 respirators conferred superior protection against CRI (RR = 0.47; 95% CI: 0.36-0.62) and laboratory-confirmed bacterial (RR = 0.46; 95% CI: 0.34-0.62), but not viral infections or ILI. Meta-analysis of observational studies provided evidence of a protective effect of masks (OR = 0.13; 95% CI: 0.03-0.62) and respirators (OR = 0.12; 95% CI: 0.06-0.26) against severe acute respiratory syndrome (SARS). This systematic review and meta-analysis supports the use of respiratory protection. However, the existing evidence is sparse and findings are inconsistent within and across studies. Multicentre RCTs with standardized protocols conducted outside epidemic periods would help to clarify the circumstances under which the use of masks or respirators is most warranted."
AUTHORS
Chee Fu Yung
Clarence C Tam
Vittoria Offeddu
Mabel Sheau Fong Low
PUBLISHED
2017 in Clinical Infectious Diseases
High quality source
Literature Review
No
No
5
The efficacy of medical masks and respirators against respiratory infection in healthcare workers.
"Objective: We aimed to examine the efficacy of medical masks and respirators in protecting against respiratory infections using pooled data from two homogenous randomised control clinical trials (RCTs).Methods: The data collected on 3591 subjects in two similar RCTs conducted in Beijing, China, which examined the same infection outcomes, were pooled. Four interventions were compared: (i) continuous N95 respirator use, (ii) targeted N95 respirator use, (iii) medical mask use and (iv) control arm. The outcomes were laboratory-confirmed viral respiratory infection, influenza A or B, laboratory-confirmed bacterial colonisation and pathogens grouped by mode of transmission.Results: Rates of all outcomes were consistently lower in the continuous N95 and/or targeted N95 arms. In adjusted analysis, rates of laboratory-confirmed bacterial colonisation (RR 0.33, 95% CI 0.21-0.51), laboratory-confirmed viral infections (RR 0.46, 95% CI 0.23-0.91) and droplet-transmitted infections (RR 0.26, 95% CI 0.16-0.42) were significantly lower in the continuous N95 arm. Laboratory-confirmed influenza was also lowest in the continuous N95 arm (RR 0.34, 95% CI 0.10-1.11), but the difference was not statistically significant. Rates of laboratory-confirmed bacterial colonisation (RR 0.54, 95% CI 0.33-0.87) and droplet-transmitted infections (RR 0.43, 95% CI 0.25-0.72) were also lower in the targeted N95 arm, but not in medical mask arm.Conclusion: The results suggest that the classification of infections into droplet versus airborne transmission is an oversimplification. Most guidelines recommend masks for infections spread by droplets. N95 respirators, as "airborne precautions," provide superior protection for droplet-transmitted infections. To ensure the occupational health and safety of healthcare worker, the superiority of respirators in preventing respiratory infections should be reflected in infection control guidelines."
AUTHORS
Bayzidur Rahman
Yang Peng
Holly Seale
Yi Zhang
Quanyi Wang
Xiaoli Wang et al
PUBLISHED
2017 in Influenza and Other Respiratory Viruses
High quality source
Yes
Yes
6
Effectiveness of N95 respirators versus surgical masks in protecting health care workers from acute respiratory infection: a systematic review and meta-analysis.
"Background: Conflicting recommendations exist related to which facial protection should be used by health care workers to prevent transmission of acute respiratory infections, including pandemic influenza. We performed a systematic review of both clinical and surrogate exposure data comparing N95 respirators and surgical masks for the prevention of transmissible acute respiratory infections.Methods: We searched various electronic databases and the grey literature for relevant studies published from January 1990 to December 2014. Randomized controlled trials (RCTs), cohort studies and case-control studies that included data on health care workers wearing N95 respirators and surgical masks to prevent acute respiratory infections were included in the meta-analysis. Surrogate exposure studies comparing N95 respirators and surgical masks using manikins or adult volunteers under simulated conditions were summarized separately. Outcomes from clinical studies were laboratory-confirmed respiratory infection, influenza-like illness and workplace absenteeism. Outcomes from surrogate exposure studies were filter penetration, face-seal leakage and total inward leakage.Results: We identified 6 clinical studies (3 RCTs, 1 cohort study and 2 case-control studies) and 23 surrogate exposure studies. In the meta-analysis of the clinical studies, we found no significant difference between N95 respirators and surgical masks in associated risk of (a) laboratory-confirmed respiratory infection (RCTs: odds ratio [OR] 0.89, 95% confidence interval [CI] 0.64-1.24; cohort study: OR 0.43, 95% CI 0.03-6.41; case-control studies: OR 0.91, 95% CI 0.25-3.36); (b) influenza-like illness (RCTs: OR 0.51, 95% CI 0.19-1.41); or (c) reported workplace absenteeism (RCT: OR 0.92, 95% CI 0.57-1.50). In the surrogate exposure studies, N95 respirators were associated with less filter penetration, less face-seal leakage and less total inward leakage under laboratory experimental conditions, compared with surgical masks.Interpretation: Although N95 respirators appeared to have a protective advantage over surgical masks in laboratory settings, our meta-analysis showed that there were insufficient data to determine definitively whether N95 respirators are superior to surgical masks in protecting health care workers against transmissible acute respiratory infections in clinical settings."
AUTHORS
Brian Schwartz
Jennie Johnstone
Gary E Garber
Ray A Copes
Colin C MacDougall
Jeffrey D Smith
PUBLISHED
2016 in CMAJ : Canadian Medical Association journal = journal de l'Association medicale canadienne
Literature Review
Couldn't Identify
Couldn't Identify
7
Respiratory and facial protection: a critical review of recent literature
"Infectious micro-organisms may be transmitted by a variety of routes. This is dependent on the particular pathogen and includes bloodborne, droplet, airborne, and contact transmission. Some micro-organisms are spread by more than one route. Respiratory and facial protection is required for those organisms which are usually transmitted via the droplet and/or airborne routes or when airborne particles have been created during 'aerosol-generating procedures'. This article presents a critical review of the recently published literature in this area that was undertaken by Health Protection Scotland and the Healthcare Infection Society and which informed the development of guidance on the use of respiratory and facial protection equipment by healthcare workers. "
AUTHORS
D. Bunyan
D. Jenkins
L. Ritchie
J.E. Coia
PUBLISHED
2013 in Journal of Hospital Infection
High quality source
Couldn't Identify
Couldn't Identify
8
Performance Evaluation of Selected N95 Respirators and Surgical Masks When Challenged with Aerosolized Endospores and Inert Particles
"The objective of this study was to assess how the relative efficiency of N95 respirators and surgical masks might vary with different challenge aerosols, utilizing a standardized manikin head form as a surrogate to human participation. A Collision nebulizer aerosolized B. anthracis Sterne strain endospores and polystyrene latex (PSL) particles to evaluate 11 models of N95 respirators and surgical masks. An automated breathing simulator, calibrated to normal tidal volume and active breathing rate, mimicked human respiration. A manikin head form with N95 respirators or surgical masks, and manikin head form without N95 respirators or surgical masks were placed in the bioaerosol chamber. An AGI-30 sampler filled with phosphate buffered water was fitted behind the mouth of each manikin head form to collect endospore bioaerosol samples. PSL aerosols concentrations were quantified by an ARTI Hand Held Particle Counter. Geometric Mean (GM) relative efficiency of N95 respirators and surgical masks challenged with endospore bioaerosol ranged from 34-65%. In PSL aerosol experiments, GM relative efficiency ranged from 35-64% for 1.3 μm particles. GM filtration efficiency of all N95 and surgical N95 respirators filter media evaluated was ≥99% when challenged with particles ≥0.1 μm. GM filtration efficiency of surgical mask filter media ranged from 70-83% with particles ≥0.1 μm and 74-92% with 1.3 μm PSL particles. Relative efficiencies of N95 respirators and surgical masks challenged with aerosolized B. anthracis endospores and PSL were similar. Relative efficiency was similar between N95 respirators and surgical masks on a manikin head form despite clear differences in filtration efficiency. This study further highlights the importance of face seal leakage in the respiratory protection provided by N95 respirators, and demonstrates it on a human surrogate."
AUTHORS
Shawn G. Gibbs
Craig S. Davidson
Adelisa L. Panlilio
Kendra K. Schmid
Pasquale V. Scarpino
Christopher F. Green et al
PUBLISHED
2013 in Journal of Occupational and Environmental Hygiene
Q3
No
No
9
A Randomized Clinical Trial of Three Options for N95 Respirators and Medical Masks in Health Workers
"Rationale: We compared three policy options for the use of medical masks and N95 respirators in healthcare workers (HCWs).Objectives: A cluster randomized clinical trial of 1,669 hospital-based HCWs in Beijing, China in the winter of 2009–2010.Methods: Participants were randomized to medical masks, N95 respirators, or targeted use of N95 respirators while doing high-risk procedures or barrier nursing. Outcomes included clinical respiratory illness (CRI) and laboratory-confirmed respiratory pathogens in symptomatic subjects.Measurements and Main Results: The rate of CRI was highest in the medical mask arm (98 of 572; 17%), followed by the targeted N95 arm (61 of 516; 11.8%), and the N95 arm (42 of 581; 7.2%) (P < 0.05). Bacterial respiratory tract colonization in subjects with CRI was highest in the medical mask arm (14.7%; 84 of 572), followed by the targeted N95 arm (10.1%; 52 of 516), and lowest in the N95 arm (6.2%; 36 of 581) (P = 0.02). After adjusting for confounders, only continuous use of N95 remained significant against CRI and bacterial colonization, and for just CRI compared with targeted N95 use. Targeted N95 use was not superior to medical masks.Conclusions: Continuous use of N95 respirators was more efficacious against CRI than intermittent use of N95 or medical masks. Most policies for HCWs recommend use of medical masks alone or targeted N95 respirator use. Continuous use of N95s resulted in significantly lower rates of bacterial colonization, a novel finding that points to more research on the clinical significance of bacterial infection in symptomatic HCWs. This study provides further data to inform occupational policy options for HCWs.Clinical trial registered with Australian New Zealand Clinical Trials Registry http://www.anzctr.org.au (ACTRN 12609000778280)."
AUTHORS
Holly Seale
Quanyi Wang
Anita Heywood
Dominic E. Dwyer
Xiaoli Wang
Anthony T. Newall et al
PUBLISHED
2013 in American Journal of Respiratory and Critical Care Medicine
High quality source
Yes
Yes
10
A cluster randomized clinical trial comparing fit-tested and non-fit-tested N95 respirators to medical masks to prevent respiratory virus infection in health care workers
"Background We compared the efficacy of medical masks, N95 respirators (fit tested and non fit tested), in health care workers (HCWs).Methods A cluster randomized clinical trial (RCT) of 1441 HCWs in 15 Beijing hospitals was performed during the 2008/2009 winter. Participants wore masks or respirators during the entire work shift for 4 weeks. Outcomes included clinical respiratory illness (CRI), influenza‐like illness (ILI), laboratory‐confirmed respiratory virus infection and influenza. A convenience no‐mask/respirator group of 481 health workers from nine hospitals was compared.Findings The rates of CRI (3·9% versus 6·7%), ILI (0·3% versus 0·6%), laboratory‐confirmed respiratory virus (1·4% versus 2·6%) and influenza (0·3% versus 1%) infection were consistently lower for the N95 group compared to medical masks. By intention‐to‐treat analysis, when P values were adjusted for clustering, non‐fit‐tested N95 respirators were significantly more protective than medical masks against CRI, but no other outcomes were significant. The rates of all outcomes were higher in the convenience no‐mask group compared to the intervention arms. There was no significant difference in outcomes between the N95 arms with and without fit testing. Rates of fit test failure were low. In a post hoc analysis adjusted for potential confounders, N95 masks and hospital level were significant, but medical masks, vaccination, handwashing and high‐risk procedures were not.Interpretation Rates of infection in the medical mask group were double that in the N95 group. A benefit of respirators is suggested but would need to be confirmed by a larger trial, as this study may have been underpowered. The finding on fit testing is specific to the type of respirator used in the study and cannot be generalized to other respirators.Trial registration Australian New Zealand Clinical Trials Registry (ANZCTR), ACTRN: ACTRN12609000257268 (http://www.anzctr.org.au)."
AUTHORS
Quanyi Wang
Simon Cauchemez
Dominic E. Dwyer
Xinghuo Pang
Xiaoli Wang
Neil Ferguson et al
PUBLISHED
2011 in Influenza and Other Respiratory Viruses
High quality source
Yes
Yes
11
A cluster randomized clinical trial comparing fit-tested and non-fit-tested N95 respirators to medical masks to prevent respiratory virus infection in health care workers.
"Background: We compared the efficacy of medical masks, N95 respirators (fit tested and non fit tested), in health care workers (HCWs).Methods: A cluster randomized clinical trial (RCT) of 1441 HCWs in 15 Beijing hospitals was performed during the 2008/2009 winter. Participants wore masks or respirators during the entire work shift for 4 weeks. Outcomes included clinical respiratory illness (CRI), influenza-like illness (ILI), laboratory-confirmed respiratory virus infection and influenza. A convenience no-mask/respirator group of 481 health workers from nine hospitals was compared.Findings: The rates of CRI (3·9% versus 6·7%), ILI (0·3% versus 0·6%), laboratory-confirmed respiratory virus (1·4% versus 2·6%) and influenza (0·3% versus 1%) infection were consistently lower for the N95 group compared to medical masks. By intention-to-treat analysis, when P values were adjusted for clustering, non-fit-tested N95 respirators were significantly more protective than medical masks against CRI, but no other outcomes were significant. The rates of all outcomes were higher in the convenience no-mask group compared to the intervention arms. There was no significant difference in outcomes between the N95 arms with and without fit testing. Rates of fit test failure were low. In a post hoc analysis adjusted for potential confounders, N95 masks and hospital level were significant, but medical masks, vaccination, handwashing and high-risk procedures were not.Interpretation: Rates of infection in the medical mask group were double that in the N95 group. A benefit of respirators is suggested but would need to be confirmed by a larger trial, as this study may have been underpowered. The finding on fit testing is specific to the type of respirator used in the study and cannot be generalized to other respirators.Trial Registration: Australian New Zealand Clinical Trials Registry (ANZCTR), ACTRN: ACTRN12609000257268 (http://www.anzctr.org.au)."
AUTHORS
Wei Duan
Simon Cauchemez
Dominic E Dwyer
Xinghuo Pang
Xiaoli Wang
Neil Ferguson et al
PUBLISHED
2011 in Influenza and Other Respiratory Viruses
High quality source
Yes
Yes
12
Physical interventions to interrupt or reduce the spread of respiratory viruses.
"Background: Viral epidemics or pandemics of acute respiratory infections like influenza or severe acute respiratory syndrome pose a world-wide threat. Antiviral drugs and vaccinations may be insufficient to prevent catastrophe.Objectives: To systematically review the effectiveness of physical interventions to interrupt or reduce the spread of respiratory viruses.Search Strategy: We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2009, issue 2); MEDLINE (1966 to May 2009); OLDMEDLINE (1950 to 1965); EMBASE (1990 to May 2009); and CINAHL (1982 to May 2009).Selection Criteria: We scanned 2958 titles, excluded 2790 and retrieved the full papers of 168 trials, to include 59 papers of 60 studies. We included any physical interventions (isolation, quarantine, social distancing, barriers, personal protection and hygiene) to prevent transmission of respiratory viruses. We included the following study designs: randomised controlled trials (RCTs), cohorts, case controls, cross-over, before-after, and time series studies.Data Collection And Analysis: We used a standardised form to assess trial eligibility. RCTs were assessed by: randomisation method; allocation generation; concealment; blinding; and follow up. Non-RCTs were assessed for the presence of potential confounders, and classified into low, medium, and high risks of bias.Main Results: The risk of bias for the four RCTs, and most cluster RCTs, was high. The observational studies were of mixed quality. Only case-control data were sufficiently homogeneous to allow meta-analysis.The highest quality cluster RCTs suggest respiratory virus spread can be prevented by hygienic measures, such as handwashing, especially around younger children. Additional benefit from reduced transmission from children to other household members is broadly supported in results of other study designs, where the potential for confounding is greater. Six case-control studies suggested that implementing barriers to transmission, isolation, and hygienic measures are effective at containing respiratory virus epidemics. We found limited evidence that N95 respirators were superior to simple surgical masks, but were more expensive, uncomfortable, and caused skin irritation. The incremental effect of adding virucidals or antiseptics to normal handwashing to decrease respiratory disease remains uncertain. Global measures, such as screening at entry ports, were not properly evaluated. There was limited evidence that social distancing was effective especially if related to the risk of exposure.Authors' Conclusions: Many simple and probably low-cost interventions would be useful for reducing the transmission of epidemic respiratory viruses. Routine long-term implementation of some of the measures assessed might be difficult without the threat of a looming epidemic."
AUTHORS
Ghada A Bawazeer
Lubna A Al-Ansary
Eliana Ferroni
Liz Dooley
Chris Del Mar
Tom Jefferson et al
PUBLISHED
2010 in Cochrane Database of Systematic Reviews
High quality source
Literature Review
No
No
13
AUTHOR
Lewis J. Radonovich
PUBLISHED
2010 in Annals of Internal Medicine
High quality source
No
No
14
Protecting healthcare workers from pandemic influenza: N95 or surgical masks?
"Objective: The successful management of an influenza pandemic will be reliant on the expertise of healthcare workers at high risk for occupationally acquired influenza. Recommended infection control measures for healthcare workers include surgical masks to protect against droplet-spread respiratory transmissible infections and N95 masks to protect against aerosol-spread infections. A literature review was undertaken for evidence of superior protective value of N95 masks or surgical masks for healthcare workers against influenza and extraneous factors influencing conferred protection.Methods: Four scientific search engines using 12 search sequences identified 21 mask studies in healthcare settings for the prevention of transmission of respiratory syncytial virus, Bordetella pertussis, and severe acute respiratory syndrome. Each was critically assessed in accordance with Australian National Health Medical Research Council guidelines. An additional 25 laboratory-based publications were also reviewed.Results: All studies reviewed used medium or lower level evidence study design. In the majority of studies, important confounders included the unrecognized impact of concurrent bundling of other infection control measures, mask compliance, contamination from improper doffing of masks, and ocular inoculation. Only three studies directly compared the protective value of surgical masks with N95 masks. The majority of laboratory studies identified both mask types as having a range of filtration efficiency, yet N95 masks afford superior protection against particles of a similar size to influenza.Conclusions: World Health Organization guidelines recommend surgical masks for all patient care with the exception of N95 masks for aerosol generating procedures. Because of the paucity of high-quality studies in the healthcare setting, the advocacy of mask types is not entirely evidence-based. Evidence from laboratory studies of potential airborne spread of influenza from shedding patients indicate that guidelines related to the current 1-meter respiratory zone may need to be extended to a larger respiratory zone and include protection from ocular inoculation."
AUTHORS
Jan Gralton
Mary-Louise McLaws
PUBLISHED
2010 in Critical Care Medicine
High quality source
Literature Review
Couldn't Identify
Couldn't Identify
15
Face Mask Use and Control of Respiratory Virus Transmission in Households
"Many countries are stockpiling face masks for use as a nonpharmaceutical intervention to control virus transmission during an influenza pandemic. We conducted a prospective cluster-randomized trial comparing surgical masks, non-fit-tested P2 masks, and no masks in prevention of influenza-like illness (ILI) in households. Mask use adherence was self-reported. During the 2006 and 2007 winter seasons, 286 exposed adults from 143 households who had been exposed to a child with clinical respiratory illness were recruited. We found that adherence to mask use significantly reduced the risk for ILI-associated infection, but <50% of participants wore masks most of the time. We concluded that household use of face masks is associated with low adherence and is ineffective for controlling seasonal respiratory disease. However, during a severe pandemic when use of face masks might be greater, pandemic transmission in households could be reduced."
AUTHORS
Gary Browne
Pamela Cheung
Holly Seale
Dominic E. Dwyer
Simon Cauchemez
C. Raina MacIntyre et al
PUBLISHED
2009 in Emerging Infectious Diseases
High quality source
Couldn't Identify
Couldn't Identify
16
Surgical Mask vs N95 Respirator for Preventing Influenza Among Health Care Workers
"Context: Data about the effectiveness of the surgical mask compared with the N95 respirator for protecting health care workers against influenza are sparse. Given the likelihood that N95 respirators will be in short supply during a pandemic and not available in many countries, knowing the effectiveness of the surgical mask is of public health importance.Objective: To compare the surgical mask with the N95 respirator in protecting health care workers against influenza.Design, Setting, And Participants: Noninferiority randomized controlled trial of 446 nurses in emergency departments, medical units, and pediatric units in 8 tertiary care Ontario hospitals.Intervention: Assignment to either a fit-tested N95 respirator or a surgical mask when providing care to patients with febrile respiratory illness during the 2008-2009 influenza season.Main Outcome Measures: The primary outcome was laboratory-confirmed influenza measured by polymerase chain reaction or a 4-fold rise in hemagglutinin titers. Effectiveness of the surgical mask was assessed as noninferiority of the surgical mask compared with the N95 respirator. The criterion for noninferiority was met if the lower limit of the 95% confidence interval (CI) for the reduction in incidence (N95 respirator minus surgical group) was greater than -9%.Results: Between September 23, 2008, and December 8, 2008, 478 nurses were assessed for eligibility and 446 nurses were enrolled and randomly assigned the intervention; 225 were allocated to receive surgical masks and 221 to N95 respirators. Influenza infection occurred in 50 nurses (23.6%) in the surgical mask group and in 48 (22.9%) in the N95 respirator group (absolute risk difference, -0.73%; 95% CI, -8.8% to 7.3%; P = .86), the lower confidence limit being inside the noninferiority limit of -9%.Conclusion: Among nurses in Ontario tertiary care hospitals, use of a surgical mask compared with an N95 respirator resulted in noninferior rates of laboratory-confirmed influenza.Trial Registration: clinicaltrials.gov Identifier: NCT00756574"
AUTHORS
Richard Webby
Stephen D. Walter
David J. D. Earn
Verne Glavin
Marek Smieja
Sylvia Chong et al
PUBLISHED
2009 in JAMA
High quality source
No
No
17
Do N95 respirators provide 95% protection level against airborne viruses, and how adequate are surgical masks?
"Background: Respiratory protection devices are used to protect the wearers from inhaling particles suspended in the air. Filtering face piece respirators are usually tested utilizing nonbiologic particles, whereas their use often aims at reducing exposure to biologic aerosols, including infectious agents such as viruses and bacteria.Methods: The performance of 2 types of N95 half-mask, filtering face piece respirators and 2 types of surgical masks were determined. The collection efficiency of these respiratory protection devices was investigated using MS2 virus (a nonharmful simulant of several pathogens). The virions were detected in the particle size range of 10 to 80 nm.Results: The results indicate that the penetration of virions through the National Institute for Occupational Safety and Health (NIOSH)-certified N95 respirators can exceed an expected level of 5%. As anticipated, the tested surgical masks showed a much higher particle penetration because they are known to be less efficient than the N95 respirators. The 2 surgical masks, which originated from the same manufacturer, showed tremendously different penetration levels of the MS2 virions: 20.5% and 84.5%, respectively, at an inhalation flow rate of 85 L/min.Conclusion: The N95 filtering face piece respirators may not provide the expected protection level against small virions. Some surgical masks may let a significant fraction of airborne viruses penetrate through their filters, providing very low protection against aerosolized infectious agents in the size range of 10 to 80 nm. It should be noted that the surgical masks are primarily designed to protect the environment from the wearer, whereas the respirators are supposed to protect the wearer from the environment."
AUTHORS
Satheesh K. Sivasubramani
Atin Adhikari
Sergey A. Grinshpun
Tiina Reponen
Mika Toivola
Anna Bałazy
PUBLISHED
2006 in American Journal of Infection Control
High quality source
No
No







ADDITIONAL STUDIES TO CONSIDER ADDING TO LIST
Total additional studies: 34
State of K's algorithms generated the list of studies below based on the studies that were added to the above list. Some of these studies may also examine: "Does an N95 mask reduce the risk of contracting viruses that cause respiratory disease better than a surgical mask?" If a study examines this question, add it to the list by pressing the button.

Only add studies that examine the same question. Do not add studies that are merely on the same topic.

Respiratory Performance Offered by N95 Respirators and Surgical Masks: Human Subject Evaluation with NaCl Aerosol Representing Bacterial and Viral Particle Size Range
"Objectives: This study aimed at determining the protection factors (PFs) provided by N95 filtering facepiece respirators and surgical masks against particles representing bacterial and viral size ranges (aerodynamic size: 0.04-1.3 mum).

Methods: The protection levels of N95 filtering facepiece respirators (four models) and surgical masks (three models) were investigated while they were donned by 12 subjects performing the OSHA (US Occupational Safety and Health Administration) fit-testing exercises in a test chamber.

Results: About 29% of N95 respirators and approximately 100% of surgical masks had PFs <10, which is the assigned PF designated for this type of respirator by the OSHA. On average, the PFs of N95 respirators were 8-12 times greater than those of surgical masks. The minimum PFs were observed in the size range of 0.04-0.2 mum. No significant difference in PF results was found between N95 respirators with and without an exhalation valve.

Conclusions: The study indicates that N95 filtering facepiece respirators may not achieve the expected protection level against bacteria and viruses. An exhalation valve on the N95 respirator does not affect the respiratory protection; it appears to be an appropriate alternative to reduce the breathing resistance.

"
PUBLISHED
2008 in The Annals of Occupational Hygiene

Add to List
Literature review
Highly regarded source
Physical interventions to interrupt or reduce the spread of respiratory viruses: systematic review.
"Objective: To review systematically the evidence of effectiveness of physical interventions to interrupt or reduce the spread of respiratory viruses.

Data Sources: Cochrane Library, Medline, OldMedline, Embase, and CINAHL, without restrictions on language or publication. Data selection Studies of any intervention to prevent the transmission of respiratory viruses (isolation, quarantine, social distancing, barriers, personal protection, and hygiene). A search of study designs included randomised trials, cohort, case-control, crossover, before and after, and time series studies. After scanning of the titles, abstracts and full text articles as a first filter, a standardised form was used to assess the eligibility of the remainder. Risk of bias of randomised studies was assessed for generation of the allocation sequence, allocation concealment, blinding, and follow-up. Non-randomised studies were assessed for the presence of potential confounders and classified as being at low, medium, or high risk of bias.

Data Synthesis: 58 papers of 59 studies were included. The quality of the studies was poor for all four randomised controlled trials and most cluster randomised controlled trials; the observational studies were of mixed quality. Meta-analysis of six case-control studies suggested that physical measures are highly effective in preventing the spread of severe acute respiratory syndrome: handwashing more than 10 times daily (odds ratio 0.45, 95% confidence interval 0.36 to 0.57; number needed to treat=4, 95% confidence interval 3.65 to 5.52), wearing masks (0.32, 0.25 to 0.40; NNT=6, 4.54 to 8.03), wearing N95 masks (0.09, 0.03 to 0.30; NNT=3, 2.37 to 4.06), wearing gloves (0.43, 0.29 to 0.65; NNT=5, 4.15 to 15.41), wearing gowns (0.23, 0.14 to 0.37; NNT=5, 3.37 to 7.12), and handwashing, masks, gloves, and gowns combined (0.09, 0.02 to 0.35; NNT=3, 2.66 to 4.97). The combination was also effective in interrupting the spread of influenza within households. The highest quality cluster randomised trials suggested that spread of respiratory viruses can be prevented by hygienic measures in younger children and within households. Evidence that the more uncomfortable and expensive N95 masks were superior to simple surgical masks was limited, but they caused skin irritation. The incremental effect of adding virucidals or antiseptics to normal handwashing to reduce respiratory disease remains uncertain. Global measures, such as screening at entry ports, were not properly evaluated. Evidence was limited for social distancing being effective, especially if related to risk of exposure-that is, the higher the risk the longer the distancing period.

Conclusion: Routine long term implementation of some of the measures to interrupt or reduce the spread of respiratory viruses might be difficult. However, many simple and low cost interventions reduce the transmission of epidemic respiratory viruses. More resources should be invested into studying which physical interventions are the most effective, flexible, and cost effective means of minimising the impact of acute respiratory tract infections."
AUTHORS
Ghada A Bawazeer
Lubna A Al-Ansary
Eliana Ferroni
Liz Dooley
Chris Del Mar
Tom Jefferson et al
PUBLISHED
2009 in BMJ : British Medical Journal

Add to List
Short Communication: Health Interventions in Volcanic Eruptions—Community Wearability Assessment of Respiratory Protection against Volcanic Ash from Mt Sinabung, Indonesia
"Inhalation of ash can be of great concern for affected communities, during and after volcanic eruptions. Governmental and humanitarian agencies recommend and distribute a variety of respiratory protection (RP), commonly surgical masks but, also, industry-certified N95-style masks. However, there is currently no evidence on how wearable they are within affected populations or how protective wearers perceive them being against volcanic ash (which will influence the likelihood of uptake of recommended interventions). Volunteers living near Mt. Sinabung, Sumatra, Indonesia, participated in a field wearability study, which included a high-efficiency mask certified to industry standards (N95-equiv.); a standard, pleated surgical mask (Surgical); a Basic flat-fold mask (Flat-fold), and the surgical mask plus a scarf tied over the top (Surgical Plus) to improve fit. These types of RP had all performed well during earlier laboratory filtration efficiency tests. The N95-equiv. mask had performed significantly better than the other RP in the subsequent total inward leakage volunteer trials, whilst the Flat-fold and Surgical masks performed poorly, letting in a third of PM"
AUTHORS
Fentiny Nugroho
Claire Horwell
Sari Mutia Timur
Karen Galea
Judith Covey
William Mueller
PUBLISHED
2018 in International Journal of Environmental Research and Public Health

Add to List
Protecting healthcare staff from severe acute respiratory syndrome: filtration capacity of multiple surgical masks
"Guidelines issued by the Centers for Disease Control and Prevention and the World Health Organisation state that healthcare workers should wear N95 masks or higher-level protection during all contact with suspected severe acute respiratory syndrome (SARS). In areas where N95 masks are not available, multiple layers of surgical masks have been tried to prevent transmission of SARS. The in vivo filtration capacity of a single surgical mask is known to be poor. However, the filtration capacity of a combination of masks is unknown. This was a crossover trial of one, two, three and five surgical masks in six volunteers to determine the in vivo filtration efficiency of wearing more than one surgical mask. We used a Portacount to measure the difference in ambient particle counts inside and outside the masks. The best combination of five surgical masks scored a fit factor of 13.7, which is well below the minimum level of 100 required for a half face respirator. Multiple surgical masks filter ambient particles poorly. They should not be used as a substitute for N95 masks unless there is no alternative."
AUTHORS
C.D. Gomersall
J.L. Derrick
PUBLISHED
2005 in Journal of Hospital Infection

Add to List
Respiratory source control using surgical masks with nanofiber media.
"Background: Potentially infected individuals ('source') are sometimes encouraged to use face masks to reduce exposure of their infectious aerosols to others ('receiver'). To improve compliance with Respiratory Source Control via face mask and therefore reduce receiver exposure, a mask should be comfortable and effective. We tested a novel face mask designed to improve breathability and filtration using nanofiber filtration.

Methods: Using radiolabeled test aerosols and a calibrated exposure chamber simulating source to receiver interaction, facepiece function was measured with a life-like ventilated manikin model. Measurements included mask airflow resistance (pressure difference during breathing), filtration, (mask capture of exhaled radiolabeled test aerosols), and exposure (the transfer of 'infectious' aerosols from the 'source' to a 'receiver'). Polydisperse aerosols were measured at the source with a mass median aerodynamic diameter of 0.95 µm. Approximately 90% of the particles were <2.0 µm. Tested facepieces included nanofiber prototype surgical masks, conventional surgical masks, and for comparison, an N95-class filtering facepiece respirator (commonly known as an 'N95 respirator'). Airflow through and around conventional surgical face mask and nanofiber prototype face mask was visualized using Schlieren optical imaging.

Results: Airflow resistance [ΔP, cmH2O] across sealed surgical masks (means: 0.1865 and 0.1791 cmH2O) approached that of the N95 (mean: 0.2664 cmH2O). The airflow resistance across the nanofiber face mask whether sealed or not sealed (0.0504 and 0.0311 cmH2O) was significantly reduced in comparison. In addition, 'infected' source airflow filtration and receiver exposure levels for nanofiber face masks placed on the source were comparable to that achieved with N95 placed on the source; 98.98% versus 82.68% and 0.0194 versus 0.0557, respectively. Compared to deflection within and around the conventional face masks, Schlieren optical imaging demonstrated enhanced airflow through the nanofiber mask.

Conclusions: Substituting nanofiber for conventional filter media significantly reduced face mask airflow resistance directing more airflow through the face mask resulting in enhanced filtration. Respiratory source control efficacy similar to that achieved through the use of an N95 respirator worn by the source and decreased airflow resistance using nanofiber masks may improve compliance and reduce receiver exposure.

"
AUTHORS
Gerald C Smaldone
Shaji D Skaria
PUBLISHED
2014 in The Annals of Occupational Hygiene

Add to List
SARS among critical care nurses, Toronto.
"To determine factors that predispose or protect healthcare workers from severe acute respiratory syndrome (SARS), we conducted a retrospective cohort study among 43 nurses who worked in two Toronto critical care units with SARS patients. Eight of 32 nurses who entered a SARS patient's room were infected. The probability of SARS infection was 6% per shift worked. Assisting during intubation, suctioning before intubation, and manipulating the oxygen mask were high-risk activities. Consistently wearing a mask (either surgical or particulate respirator type N95) while caring for a SARS patient was protective for the nurses, and consistent use of the N95 mask was more protective than not wearing a mask. Risk was reduced by consistent use of a surgical mask, but not significantly. Risk was lower with consistent use of a N95 mask than with consistent use of a surgical mask. We conclude that activities related to intubation increase SARS risk and use of a mask (particularly a N95 mask) is protective."
AUTHORS
David Rose
Stephen D Walter
Karen Green
Marianna Ofner
Lorraine Moss
Stephanie Smith et al
PUBLISHED
2004 in Emerging Infectious Diseases

Add to List
A review of studies on animal reservoirs of the SARS coronavirus
"In this review, we summarize the researches on animal reservoirs of the SARS coronavirus (SARS-CoV). Masked palm civets were suspected as the origin of the SARS outbreak in 2003 and was confirmed as the direct origin of SARS cases with mild symptom in 2004. Sequence analysis of the SARS-CoV-like virus in masked palm civets indicated that they were highly homologous to human SARS-CoV with nt identity over 99.6%, indicating the virus has not been circulating in the population of masked palm civets for a very long time. Alignment of 10 complete viral genome sequences from masked palm civets with those of human SARS-CoVs revealed 26 conserved single-nucleotide variations (SNVs) in the viruses from masked palm civets. These conserved SNVs were gradually lost from the genomes of viruses isolated from the early phase to late phase human patients of the 2003 SARS epidemic. In 2005, horseshoe bats were identified as the natural reservoir of a group of coronaviruses that are distantly related to SARS-CoV. The genome sequences of bat SARS-like coronavirus had about 88-92% nt identity with that of the SARS-CoV. The prevalence of antibodies and viral RNA in different bat species and the characteristics of the bat SARS-like coronavirus were elucidated. Apart from masked palm civets and bats, 29 other animal species had been tested for the SARS-CoV, and the results are summarized in this paper."
AUTHORS
Zhihong Hu
Zhengli Shi
PUBLISHED
2008 in Virus Research

Add to List
Angiotensin-converting enzyme 2 (ACE2) from raccoon dog can serve as an efficient receptor for the spike protein of severe acute respiratory syndrome coronavirus
"Raccoon dog is one of the suspected intermediate hosts of severe acute respiratory syndrome coronavirus (SARS-CoV). In this study, the angiotensin-converting enzyme 2 (ACE2) gene of raccoon dog (rdACE2) was cloned and sequenced. The amino acid sequence of rdACE2 has identities of 99.3, 89.2, 83.9 and 80.4 % to ACE2 proteins from dog, masked palm civet (pcACE2), human (huACE2) and bat, respectively. There are six amino acid changes in rdACE2 compared with huACE2, and four changes compared with pcACE2, within the 18 residues of ACE2 known to make direct contact with the SARS-CoV S protein. A HeLa cell line stably expressing rdACE2 was established; Western blot analyses and an enzyme-activity assay indicated that the cell line expressed ACE2 at a similar level to two previously established cell lines that express ACE2 from human and masked palm civet, respectively. Human immunodeficiency virus-backboned pseudoviruses expressing spike proteins derived from human SARS-CoV or SARS-CoV-like viruses of masked palm civets and raccoon dogs were tested for their entry efficiency into these cell lines. The results showed that rdACE2 is a more efficient receptor for human SARS-CoV, but not for SARS-CoV-like viruses of masked palm civets and raccoon dogs, than huACE2 or pcACE2. This study provides useful data to elucidate the role of raccoon dog in SARS outbreaks."
AUTHORS
H. Deng
Y. Zhang
L. Xu
Z. Chen
Z. Ma
Y. Liu et al
PUBLISHED
2009 in Journal of General Virology

Add to List
Civets are equally susceptible to experimental infection by two different severe acute respiratory syndrome coronavirus isolates.
"Severe acute respiratory syndrome (SARS) was caused by a novel virus now known as SARS coronavirus (SARS-CoV). The discovery of SARS-CoV-like viruses in masked palm civets (Paguma larvata) raises the possibility that civets play a role in SARS-CoV transmission. To test the susceptibility of civets to experimental infection by different SARS-CoV isolates, 10 civets were inoculated with two human isolates of SARS-CoV, BJ01 (with a 29-nucleotide deletion) and GZ01 (without the 29-nucleotide deletion). All inoculated animals displayed clinical symptoms, such as fever, lethargy, and loss of aggressiveness, and the infection was confirmed by virus isolation, detection of viral genomic RNA, and serum-neutralizing antibodies. Our data show that civets were equally susceptible to SARS-CoV isolates GZ01 and BJ01."
AUTHORS
Bryan T Eaton
Jinfu Sun
Yedong Yu
Li Feng
Chaoan Xin
Nihong Liu et al
PUBLISHED
2005 in Journal of Virology

Add to List
Testing the hypothesis of a recombinant origin of the SARS-associated coronavirus
"The origin of severe acute respiratory syndrome-associated corona-virus (SARS-CoV) is still a matter of speculation, although more than one year has passed since the onset of the SARS outbreak. In this study, we implemented a 3-step strategy to test the intriguing hypothesis that SARS-CoV might have been derived from a recombinant virus. First, we blasted the whole SARS-CoV genome against a virus database to search viruses of interest. Second, we employed 7 recombination detection techniques well documented in successfully detecting recombination events to explore the presence of recombination in SARS-CoV genome. Finally, we conducted phylogenetic analyses to further explore whether recombination has indeed occurred in the course of coronaviruses history predating the emergence of SARS-CoV. Surprisingly, we found that 7 putative recombination regions, located in Replicase 1ab and Spike protein, exist between SARS-CoV and other 6 coronaviruses: porcine epidemic diarrhea virus (PEDV), transmissible gastroenteritis virus (TGEV), bovine coronavirus (BCoV), human coronavirus 229E (HCoV), murine hepatitis virus (MHV), and avian infectious bronchitis virus (IBV). Thus, our analyses substantiate the presence of recombination events in history that led to the SARS-CoV genome. Like the other coronaviruses used in the analysis, SARS-CoV is also a mosaic structure."
AUTHORS
A. Danchin
Y. L. Yap
X. W. Zhang
PUBLISHED

Add to List
The phylogeny of SARS coronavirus
"Different tree-building methods consistently place the SARS corona-virus (SARS-CoV) as a basal Group 2 coronavirus rather than as an ungrouped species as concluded by others. Detailed comparisons of the SARS-CoV genomic sequence with those of six other coronaviruses failed to find evidence of recombination or genomic rearrangement using computational methods designed for that purpose."
AUTHORS
A. J. Gibbs
J. S. Armstrong
M. J. Gibbs
PUBLISHED
2004 in Archives of Virology

Add to List
Systematic Comparison of Two Animal-to-Human Transmitted Human Coronaviruses: SARS-CoV-2 and SARS-CoV
"After the outbreak of the severe acute respiratory syndrome (SARS) in the world in 2003, human coronaviruses (HCoVs) have been reported as pathogens that cause severe symptoms in respiratory tract infections. Recently, a new emerged HCoV isolated from the respiratory epithelium of unexplained pneumonia patients in the Wuhan seafood market caused a major disease outbreak and has been named the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). This virus causes acute lung symptoms, leading to a condition that has been named as “coronavirus disease 2019” (COVID-19). The emergence of SARS-CoV-2 and of SARS-CoV caused widespread fear and concern and has threatened global health security. There are some similarities and differences in the epidemiology and clinical features between these two viruses and diseases that are caused by these viruses. The goal of this work is to systematically review and compare between SARS-CoV and SARS-CoV-2 in the context of their virus incubation, originations, diagnosis and treatment methods, genomic and proteomic sequences, and pathogenic mechanisms."
AUTHORS
Jiabao Xu
Yunlong Wang
Xiangqian Guo
Wan Zhu
Longxiang Xie
Tieshan Teng et al
PUBLISHED
2020 in Viruses

Add to List
Noninvasive ventilation masks with viral filters to protect health care workers from SARS-CoV-2 / Coronavirus infections
"Abstract

Background:There is a shortage of masks and respirators for the protection of health care professionals during the current SARS-CoV-2 / Coronavirus pandemic. Masks for non-invasive ventilation (NIV) in combination with viral-proof filters could serve as an alternative protection measure. We wanted to determine the aerosol filtering efficacies of such devices in comparison to conventional surgical masks, N95 and FFP3 respirators.Method:Masks and respirators were mounted on a ventilated mannequin head in a test-chamber. Absorption of radioactive particles was measured compared to a non-filtered reference port.Results: Filter efficacies were 93.3 ± 1.5 % for a ResMed AcuCare NIV-mask plus filter, 71.2 ± 0.2 % for a ResMed Mirage Quattro FX NIV-mask plus filter, 89.4 ± 0.9 % for a Loewenstein JOYCEclinc FF NIV-mask plus filter, 48.4 ± 4 % for a surgical mask with rubber band, 60.5 ± 9.1 % for a surgical mask with ribbons, 56.9 ± 7.5 % for a FFP3 respirator, 64.5 % ± 5.1 for a N95 respirator. The ResMed AcuCare and the Loewenstein JOYCEclinic FF mask were more effective than any other of the tested devices (p &lt; 0.001 and p = 0.001 respectively)Conclusion:NIV masks with viral-proof filters effectively filter respirable particles. Two tested NIV masks were more effective than the tested FFP3 and N95 respirators.
"
AUTHORS
Peter Haidl
Jens Kerl
Dominic Dellweg
Dieter Koehler
PUBLISHED
2020 in Research Square

Add to List
Compounds with therapeutic potential against novel respiratory 2019 coronavirus
"Currently, the expansion of the novel human respiratory coronavirus (known as: SARS-CoV-2, COVID-2019, or 2019-nCoV) has stressed the need for therapeutic alternatives to alleviate and stop this new epidemic. The previous epidemics of high-morbidity human coronaviruses, such as the acute respiratory syndrome coronavirus (SARS-CoV) in 2003, and the Middle East respiratory syndrome corona virus (MERS-CoV) in 2012, prompted the characterization of compounds that could be potentially active against the currently emerging novel coronavirus SARS-CoV-2. The most promising compound is remdesivir (GS-5734), a nucleotide analog prodrug currently in clinical trials for treating Ebola virus infections. Remdesivir inhibited the replication of SARS-CoV and MERS-CoV in tissue cultures, and it displayed efficacy in non-human animal models. In addition, a combination of the human immunodeficiency virus type 1 (HIV-1) protease inhibitors, lopinavir/ritonavir, and interferon beta (LPV/RTV-INFb) were shown to be effective in patients infected with SARS-CoV. LPV/RTV-INFb also improved clinical parameters in marmosets and mice infected with MERS-CoV. Remarkably, the therapeutic efficacy of remdesivir appeared to be superior to that of LPV/RTV-INFb against MERS-CoV in a transgenic humanized mice model. The relatively high mortality rates associated with these three novel human coronavirus infections, SARS-CoV, MERS-CoV, and SARS-CoV-2, has suggested that pro-inflammatory responses might play a role in the pathogenesis. It remains unknown whether the generated inflammatory state should be targeted. Therapeutics that target the coronavirus alone might not be able to reverse highly pathogenic infections. This minireview aimed to provide a summary of therapeutic compounds that showed potential in fighting SARS-CoV-2 infections."
AUTHOR
Miguel Angel Martinez
PUBLISHED
2020 in Antimicrobial Agents and Chemotherapy

Add to List
Sitagliptin: a potential drug for the treatment of SARS-CoV-2?
"Recently, an outbreak of fatal coronavirus, SARS-CoV-2, has emerged from China and is rapidly spreading worldwide. As the coronavirus pandemic rages, drug discovery and development become even more challenging. Drug repurposing of the antimalarial drug chloroquine and its hydroxylated form had demonstrated apparent effectiveness in the treatment of COVID-19 associated pneumonia in clinical trials. SARS-CoV-2 spike protein shares 31.9% sequence identity with the spike protein presents in the Middle East Respiratory Syndrome Corona Virus (MERS-CoV), which infects cells through the interaction of its spike protein with the DPP4 receptor found on macrophages. Sitagliptin, a DPP4 inhibitor, that is known for its antidiabetic, immunoregulatory, anti-inflammatory, and beneficial cardiometabolic effects has been shown to reverse macrophage responses in MERS-CoV infection and reduce CXCL10 chemokine production in AIDS patients. We suggest that Sitagliptin may be beneficial alternative for the treatment of COVID-19 disease especially in diabetic patients and patients with preexisting cardiovascular conditions who are already at higher risk of COVID-19 infection."
AUTHOR
Sanaa Bardaweel
PUBLISHED
2020 in Center for Open Science

Add to List
Association between 2019-nCoV transmission and N95 respirator use
"2019-nCoV had caused pneumonia outbreak in Wuhan. Existing evidence have confirmed the human-to-human transmission of 2019-nCoV. We retrospectively collected infection data from 2 January to 22 January at six departments from Zhongnan Hospital of Wuhan University. In our study, we found N95 respirators, disinfection and hand washing can help to reduce the risk of 2019-nCoV infection in medical staffs. Our results call for re-emphasizing strict occupational protection code in battling this novel contagious disease. The risk of 2019-nCoV infection was higher in the open area than in the quarantined area. N95 may be more effective for 2019-nCoV infections."
AUTHORS
Zhenshun Cheng
Zhenyu Pan
Xinghuan Wang
PUBLISHED
2020 in Cold Spring Harbor Laboratory

Add to List
CT Manifestations and Clinical Features of the 2019 Novel Coronavirus Pneumonia Infected by Cluster Transmission Within a Family: Case Report
"Abstract

Background: In December 2019, a cluster of patients associated with a seafood wholesale market was confirmed having infected the 2019 novel coronavirus (2019-nCoV) in Wuhan, China. As of Feb 11, 2020, 43144 cases of the 2019-nCoV infection have been confirmed in the world, and person-to-person transmission has been recognized. To our knowledge, there are no reports regarding the 2019-nCoV pneumonia infected by cluster transmission within a family. The amount of close contact suspect was increasing. We reported cases of family cluster transmission of the 2019-nCoV infection, showing the differences in computed tomography (CT) manifestations and symptoms between patients with and without history of exposure to the epidemic area (Wuhan).Case Presentation: A 48-year-old man was presented to the hospital in Jan 30, 2020 with a 2-day history of low fever and chill. He had traveled to Wuhan City of Hubei Province of China 12 days before, and was confirmed having the 2019-nCoV infection based on his positive CT manifestations, clinical signs, and real-time fluorescence polymerase chain reaction results. The other three members of his family without history of exposure to the epidemic area (Wuhan) were subsequently identified having the 2019-nCoV transmissive infection based on the positive findings of real-time fluorescence polymerase chain reaction, but they did not have abnormal CT manifestations and clinical signs.Conclusion: For patients who have history of exposure to the epidemic area (Wuhan), the 2019-nCoV infected pneumonia can be identified by real-time fluorescence polymerase chain reaction testing and chest CT together with the symptoms. But for patients without exposure to the epidemic area, the 2019-nCoV infection can be confirmed by real-time fluorescence polymerase chain reaction testing and history of close contact with confirmed patients who have history of exposure to the epidemic area.
"
AUTHORS
Li-qin Yang
Yu-ping Wu
Jin-ming Cao
Hong-jun Li
Xiao-ming Zhang
Tian-wu Chen et al
PUBLISHED
2020 in Research Square

Add to List
Receptor recognition by novel coronavirus from Wuhan: An analysis based on decade-long structural studies of SARS
"Recently a novel coronavirus (2019-nCoV) has emerged from Wuhan, China, causing symptoms in humans similar to those caused by SARS coronavirus (SARS-CoV). Since SARS-CoV outbreak in 2002, extensive structural analyses have revealed key atomic-level interactions between SARS-CoV spike protein receptor-binding domain (RBD) and its host receptor angiotensin-converting enzyme 2 (ACE2), which regulate both the cross-species and human-to-human transmissions of SARS-CoV. Here we analyzed the potential receptor usage by 2019-nCoV, based on the rich knowledge about SARS-CoV and the newly released sequence of 2019-nCoV. First, the sequence of 2019-nCoV RBD, including its receptor-binding motif (RBM) that directly contacts ACE2, is similar to that of SARS-CoV, strongly suggesting that 2019-nCoV uses ACE2 as its receptor. Second, several critical residues in 2019-nCoV RBM (particularly Gln493) provide favorable interactions with human ACE2, consistent with 2019-nCoV's capacity for human cell infection. Third, several other critical residues in 2019-nCoV RBM (particularly Asn501) are compatible with, but not ideal for, binding human ACE2, suggesting that 2019-nCoV has acquired some capacity for human-to-human transmission. Last, while phylogenetic analysis indicates a bat origin of 2019-nCoV, 2019-nCoV also potentially recognizes ACE2 from a diversity of animal species (except mice and rats), implicating these animal species as possible intermediate hosts or animal models for 2019-nCoV infections. These analyses provide insights into the receptor usage, cell entry, host cell infectivity and animal origin of 2019-nCoV, and may help epidemic surveillance and preventive measures against 2019-nCoV."
AUTHORS
F Li
RS Baric
R Graham
J Shang
Y Wan
PUBLISHED
2020 in Journal of Virology

Add to List
Receptor Recognition by the Novel Coronavirus from Wuhan: an Analysis Based on Decade-Long Structural Studies of SARS Coronavirus
FUNDERS
National Institute of Allergy and Infectious Diseases
"ABSTRACT
Recently, a novel coronavirus (2019-nCoV) has emerged from Wuhan, China, causing symptoms in humans similar to those caused by severe acute respiratory syndrome coronavirus (SARS-CoV). Since the SARS-CoV outbreak in 2002, extensive structural analyses have revealed key atomic-level interactions between the SARS-CoV spike protein receptor-binding domain (RBD) and its host receptor angiotensin-converting enzyme 2 (ACE2), which regulate both the cross-species and human-to-human transmissions of SARS-CoV. Here, we analyzed the potential receptor usage by 2019-nCoV, based on the rich knowledge about SARS-CoV and the newly released sequence of 2019-nCoV. First, the sequence of 2019-nCoV RBD, including its receptor-binding motif (RBM) that directly contacts ACE2, is similar to that of SARS-CoV, strongly suggesting that 2019-nCoV uses ACE2 as its receptor. Second, several critical residues in 2019-nCoV RBM (particularly Gln493) provide favorable interactions with human ACE2, consistent with 2019-nCoV’s capacity for human cell infection. Third, several other critical residues in 2019-nCoV RBM (particularly Asn501) are compatible with, but not ideal for, binding human ACE2, suggesting that 2019-nCoV has acquired some capacity for human-to-human transmission. Last, while phylogenetic analysis indicates a bat origin of 2019-nCoV, 2019-nCoV also potentially recognizes ACE2 from a diversity of animal species (except mice and rats), implicating these animal species as possible intermediate hosts or animal models for 2019-nCoV infections. These analyses provide insights into the receptor usage, cell entry, host cell infectivity and animal origin of 2019-nCoV and may help epidemic surveillance and preventive measures against 2019-nCoV.
IMPORTANCE The recent emergence of Wuhan coronavirus (2019-nCoV) puts the world on alert. 2019-nCoV is reminiscent of the SARS-CoV outbreak in 2002 to 2003. Our decade-long structural studies on the receptor recognition by SARS-CoV have identified key interactions between SARS-CoV spike protein and its host receptor angiotensin-converting enzyme 2 (ACE2), which regulate both the cross-species and human-to-human transmissions of SARS-CoV. One of the goals of SARS-CoV research was to build an atomic-level iterative framework of virus-receptor interactions to facilitate epidemic surveillance, predict species-specific receptor usage, and identify potential animal hosts and animal models of viruses. Based on the sequence of 2019-nCoV spike protein, we apply this predictive framework to provide novel insights into the receptor usage and likely host range of 2019-nCoV. This study provides a robust test of this reiterative framework, providing the basic, translational, and public health research communities with predictive insights that may help study and battle this novel 2019-nCoV."
AUTHORS
Fang Li
Rachel Graham
Yushun Wan
Jian Shang
Ralph S. Baric
PUBLISHED
2020 in Journal of Virology

Add to List
Promising Inhibitor for 2019-nCoV in Drug Development
"The 2019 novel coronavirus (2019-nCoV), which is first detected in Wuhan, China, is a virus identified as the cause of pneumonia. In the event of epidemic outbreak, a series of actions have taken by the Chinese government to control the pandemic of the virus, and the effective medical methods are in urgent need to prevent 2019-nCoV infection and cure the disease, especially a drug that can suppress 2019-nCoV is urgently needed. However, there are no specific drugs and vaccine that can prevent coronavirus infection. Some research works on the transmissibility, severity, and other features associated with this virus are ongoing. Some works about new drug against 2019-nCoV are carried out, more time is required to develop an effective drug against pneumonia caused by 2019-nCoV. Now, to develop broad spectrum anti-viral agents, there is quickly method to identify drugs with high binding capacity with 2019-nCoV by virtual screening based on the clinical drug libraries, all these drugs have been widely used in clinical applications with guaranteed safety, which may serve as promising candidates to treat the infection of 2019-nCoV. In this paper, we summarize the discovery and clinical application of specific drugs against 2019-nCoV as potential inhibitors to alleviate the current epidemic."
AUTHORS
Zilong Dang
Xiaohui Xu
PUBLISHED
2020 in Center for Open Science

Add to List
Full-genome evolutionary analysis of the novel corona virus (2019-nCoV) rejects the hypothesis of emergence as a result of a recent recombination event
"Background
A novel coronavirus (2019-nCoV) associated with human to human transmission and severe human infection has been recently reported from the city of Wuhan in China. Our objectives were to characterize the genetic relationships of the 2019-nCoV and to search for putative recombination within the subgenus of sarbecovirus.

Methods
Putative recombination was investigated by RDP4 and Simplot v3.5.1 and discordant phylogenetic clustering in individual genomic fragments was confirmed by phylogenetic analysis using maximum likelihood and Bayesian methods.

Results
Our analysis suggests that the 2019-nCoV although closely related to BatCoV RaTG13 sequence throughout the genome (sequence similarity 96.3%), shows discordant clustering with the Bat_SARS-like coronavirus sequences. Specifically, in the 5′-part spanning the first 11,498 nucleotides and the last 3′-part spanning 24,341–30,696 positions, 2019-nCoV and RaTG13 formed a single cluster with Bat_SARS-like coronavirus sequences, whereas in the middle region spanning the 3′-end of ORF1a, the ORF1b and almost half of the spike regions, 2019-nCoV and RaTG13 grouped in a separate distant lineage within the sarbecovirus branch.

Conclusions
The levels of genetic similarity between the 2019-nCoV and RaTG13 suggest that the latter does not provide the exact variant that caused the outbreak in humans, but the hypothesis that 2019-nCoV has originated from bats is very likely. We show evidence that the novel coronavirus (2019-nCov) is not-mosaic consisting in almost half of its genome of a distinct lineage within the betacoronavirus. These genomic features and their potential association with virus characteristics and virulence in humans need further attention."
AUTHORS
G Magiorkinis
EG Kostaki
D Paraskevis
PUBLISHED
2020 in Infection

Add to List
Full-genome evolutionary analysis of the novel corona virus (2019-nCoV) rejects the hypothesis of emergence as a result of a recent recombination event
"AbstractBackgroundA novel coronavirus (2019-nCoV) associated with human to human transmission and severe human infection has been recently reported from the city of Wuhan in China. Our objectives were to characterize the genetic relationships of the 2019-nCoV and to search for putative recombination within the subgenus of sarbecovirus.MethodsPutative recombination was investigated by RDP4 and Simplot v3.5.1 and discordant phylogenetic clustering in individual genomic fragments was confirmed by phylogenetic analysis using maximum likelihood and Bayesian methods.ResultsOur analysis suggests that the 2019-nCoV although closely related to BatCoV RaTG13 sequence throughout the genome (sequence similarity 96.3%), shows discordant clustering with the Bat-SARS-like coronavirus sequences. Specifically, in the 5’-part spanning the first 11,498 nucleotides and the last 3’-part spanning 24,341-30,696 positions, 2019-nCoV and RaTG13 formed a single cluster with Bat-SARS-like coronavirus sequences, whereas in the middle region spanning the 3’-end of ORF1a, the ORF1b and almost half of the spike regions, 2019-nCoV and RaTG13 grouped in a separate distant lineage within the sarbecovirus branch.ConclusionsThe levels of genetic similarity between the 2019-nCoV and RaTG13 suggest that the latter does not provide the exact variant that caused the outbreak in humans, but the hypothesis that 2019-nCoV has originated from bats is very likely. We show evidence that the novel coronavirus (2019-nCov) is not-mosaic consisting in almost half of its genome of a distinct lineage within the betacoronavirus. These genomic features and their potential association with virus characteristics and virulence in humans need further attention."
AUTHORS
S. Tsiodras
G. Panayiotakopoulos
G. Magiorkinis
E.G. Kostaki
D. Paraskevis
PUBLISHED
2020 in Cold Spring Harbor Laboratory

Add to List
The novel coronavirus 2019 (2019-nCoV) uses the SARS-coronavirus receptor ACE2 and the cellular protease TMPRSS2 for entry into target cells
"AbstractThe emergence of a novel, highly pathogenic coronavirus, 2019-nCoV, in China, and its rapid national and international spread pose a global health emergency. Coronaviruses use their spike proteins to select and enter target cells and insights into nCoV-2019 spike (S)-driven entry might facilitate assessment of pandemic potential and reveal therapeutic targets. Here, we demonstrate that 2019-nCoV-S uses the SARS-coronavirus receptor, ACE2, for entry and the cellular protease TMPRSS2 for 2019-nCoV-S priming. A TMPRSS2 inhibitor blocked entry and might constitute a treatment option. Finally, we show that the serum form a convalescent SARS patient neutralized 2019-nCoV-S-driven entry. Our results reveal important commonalities between 2019-nCoV and SARS-coronavirus infection, which might translate into similar transmissibility and disease pathogenesis. Moreover, they identify a target for antiviral intervention.One sentence summaryThe novel 2019 coronavirus and the SARS-coronavirus share central biological properties which can guide risk assessment and intervention."
AUTHORS
Hannah Kleine-Weber
Stefan Pöhlmann
Nadine Krüger
Marcel Müller
Christian Drosten
Markus Hoffmann
PUBLISHED
2020 in Cold Spring Harbor Laboratory

Add to List
Identification of 2019-nCoV related coronaviruses in Malayan pangolins in southern China
"AbstractThe ongoing outbreak of viral pneumonia in China and beyond is associated with a novel coronavirus, provisionally termed 2019-nCoV. This outbreak has been tentatively associated with a seafood market in Wuhan, China, where the sale of wild animals may be the source of zoonotic infection. Although bats are likely reservoir hosts for 2019-nCoV, the identity of any intermediate host facilitating transfer to humans is unknown. Here, we report the identification of 2019-nCoV related coronaviruses in pangolins (Manis javanica) seized in anti-smuggling operations in southern China. Metagenomic sequencing identified pangolin associated CoVs that belong to two sub-lineages of 2019-nCoV related coronaviruses, including one very closely related to 2019-nCoV in the receptor-binding domain. The discovery of multiple lineages of pangolin coronavirus and their similarity to 2019-nCoV suggests that pangolins should be considered as possible intermediate hosts for this novel human virus and should be removed from wet markets to prevent zoonotic transmission."
AUTHORS
Yi-Gang Tong
Yi Guan
Yan-Ling Hu
Wen-Juan Li
Wei Wei
Lian-Feng Li et al
PUBLISHED
2020 in Cold Spring Harbor Laboratory

Add to List
Surgical mask versus N95 respirator for preventing influenza among health care workers: a randomized trial.
"CONTEXT:
Data about the effectiveness of the surgical mask compared with the N95 respirator for protecting health care workers against influenza are sparse. Given the likelihood that N95 respirators will be in short supply during a pandemic and not available in many countries, knowing the effectiveness of the surgical mask is of public health importance.

OBJECTIVE:
To compare the surgical mask with the N95 respirator in protecting health care workers against influenza.

DESIGN, SETTING, AND PARTICIPANTS:
Noninferiority randomized controlled trial of 446 nurses in emergency departments, medical units, and pediatric units in 8 tertiary care Ontario hospitals.

INTERVENTION:
Assignment to either a fit-tested N95 respirator or a surgical mask when providing care to patients with febrile respiratory illness during the 2008-2009 influenza season.

MAIN OUTCOME MEASURES:
The primary outcome was laboratory-confirmed influenza measured by polymerase chain reaction or a 4-fold rise in hemagglutinin titers. Effectiveness of the surgical mask was assessed as noninferiority of the surgical mask compared with the N95 respirator. The criterion for noninferiority was met if the lower limit of the 95% confidence interval (CI) for the reduction in incidence (N95 respirator minus surgical group) was greater than -9%.

RESULTS:
Between September 23, 2008, and December 8, 2008, 478 nurses were assessed for eligibility and 446 nurses were enrolled and randomly assigned the intervention; 225 were allocated to receive surgical masks and 221 to N95 respirators. Influenza infection occurred in 50 nurses (23.6%) in the surgical mask group and in 48 (22.9%) in the N95 respirator group (absolute risk difference, -0.73%; 95% CI, -8.8% to 7.3%; P = .86), the lower confidence limit being inside the noninferiority limit of -9%.

CONCLUSION:
Among nurses in Ontario tertiary care hospitals, use of a surgical mask compared with an N95 respirator resulted in noninferior rates of laboratory-confirmed influenza."
AUTHORS
Damon Atrie
Andrew Worster
PUBLISHED
2012 in CJEM

Add to List
Efficacy of face masks and respirators in preventing upper respiratory tract bacterial colonization and co-infection in hospital healthcare workers
"Objective: We compared the efficacy of medical masks (MM) and N95 respirators (N95) in preventing bacterial colonization/infection in healthcare workers (HCWs).

Methods: A cluster randomized clinical trial (RCT) of 1441 hospital HCWs randomized to medical masks or N95 respirators, and compared to 481 control HCWs, was performed in Beijing, China, during the winter season of 2008-2009. Participants were followed for development of clinical respiratory illness (CRI). Symptomatic subjects were tested for Streptococcus pneumoniae, Bordetella pertussis, Chlamydia pneumoniae, Mycoplasma pneumoniae or Haemophilus influenza type B by multiplex polymerase chain reaction (PCR).

Results: The rate of bacterial colonization was 2.8% in the N95 group (p=0.02), 5.3% among medical mask users (p<0.01) and 7.5% among the controls (p=0.16). N95 respirators were significantly protective (adjusted RR 0.34, 95% CI: 0.21-0.56) against bacterial colonization. Co-infections of two bacteria or a virus and bacteria occurred in up to 3.7% of HCWs, and were significantly lower in the N95 arm.

Conclusions: N95 respirators were significantly protective against bacterial colonization, co-colonization and viral-bacterial co-infection. We showed that dual respiratory virus or bacterial-viral co-infections can be reduced by the use of N95 respirators. This study has occupational health and safety implications for health workers.

"
AUTHORS
Zhanhai Gao
Iman Ridda
Holly Seale
Bayzidur Rahman
Quanyi Wang
C. Raina MacIntyre et al
PUBLISHED
2014 in Preventive Medicine

Add to List
The Respiratory Protection Effectiveness Clinical Trial (ResPECT): a cluster-randomized comparison of respirator and medical mask effectiveness against respiratory infections in healthcare personnel.
"Background: Although N95 filtering facepiece respirators and medical masks are commonly used for protection against respiratory infections in healthcare settings, more clinical evidence is needed to understand the optimal settings and exposure circumstances for healthcare personnel to use these devices. A lack of clinically germane research has led to equivocal, and occasionally conflicting, healthcare respiratory protection recommendations from public health organizations, professional societies, and experts.

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

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

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

"
AUTHORS
Cynthia Gibert
Charlotte Gaydos
Aaron Eagan
Derek A Cummings
Mary T Bessesen
Lewis J Radonovich et al
PUBLISHED

Add to List
The need of health policy perspective to protect Healthcare Workers during COVID-19 pandemic. A GRADE rapid review on the N95 respirators effectiveness.
"Background Protecting Health Care Workers (HCWs) during routine care of suspected or confirmed COVID-19 patients is of paramount importance to halt the SARS-CoV-2 (Severe Acute Respiratory Syndrome-Coronavirus-2) pandemic. The WHO, ECDC and CDC have issued conflicting guidelines on the use of respiratory filters (N95) by HCWs.
Methods We searched PubMed, Embase and The Cochrane Library from the inception to March 21, 2020 to identify randomized controlled trials (RCTs) comparing N95 respirators versus surgical masks for prevention of COVID-19 or any other respiratory infection among HCWs. The grading of recommendations, assessment, development, and evaluation (GRADE) was used to evaluate the quality of evidence.
Findings Four RCTs involving 8736 HCWs were included. We did not find any trial specifically on prevention of COVID-19. However, wearing N95 respirators can prevent 73 more (95% CI 46-91) clinical respiratory infections per 1000 HCWs compared to surgical masks (2 RCTs; 2594 patients; low quality of evidence). A protective effect of N95 respirators in laboratory-confirmed bacterial colonization (RR= 0.41; 95%CI 0.28-0.61) was also found. A trend in favour of N95 respirators was observed in preventing laboratory-confirmed respiratory viral infections, laboratory-confirmed respiratory infection, and influenza like illness.
Interpretation We found no direct high quality evidence on whether N95 respirators are better than surgical masks for HCWs protection from SARS-CoV-2. However, low quality evidence suggests that N95 respirators protect HCWs from clinical respiratory infections. This finding should be contemplated to decide the best strategy to support the resilience of healthcare systems facing the potentially catastrophic SARS-CoV-2 pandemic."
AUTHORS
Greta Castellini
Primiano Iannone
Silvia Gianola
Daniela D'Angelo
Claudio Mastroianni
Giuseppe La Torre et al
PUBLISHED
2020 in Cold Spring Harbor Laboratory

Add to List
Effect of various decontamination procedures on disposable N95 mask integrity and SARS-CoV-2 infectivity
"The COVID-19 pandemic has created a high demand on personal protective equipment, including disposable N95 masks. Given the need for mask reuse, we tested the feasibility of vaporized hydrogen peroxide (VHP), ultraviolet light (UV), and ethanol decontamination strategies on N95 mask integrity and the ability to remove the infectious potential of SARS-CoV-2. FIT test data showed functional degradation by both ethanol and UV decontamination to different degrees. VHP treated masks showed no significant change in function after two treatments. We also report a single SARS-CoV-2 virucidal experiment using Vero E6 cell infection. We hope our data will guide further research for evidenced-based decisions for disposable N95 mask reuse and help protect caregivers from SARS-CoV-2 and other pathogens."
AUTHORS
John Welle
Haley Hanseler
Tacy Brotherton
Jeffrey S. Smith
Nicholas L. Stucky
Carlo B. Bifulco et al
PUBLISHED
2020 in Cold Spring Harbor Laboratory

Add to List
Human monoclonal antibodies block the binding of SARS-CoV-2 spike protein to angiotensin converting enzyme 2 receptor
"The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused a global pandemic of novel corona virus disease (COVID-19). To date, no prophylactic vaccines or approved therapeutic agents are available for preventing and treating this highly transmittable disease. Here we report two monoclonal antibodies (mAbs) cloned from memory B cells of patients recently recovered from COVID-19, and both mAbs specifically bind to the spike (S) protein of SARS-CoV-2, block the binding of receptor binding domain (RBD) of SARS-CoV-2 to human angiotensin converting enzyme 2 (hACE2), and effectively neutralize S protein-pseudotyped virus infection. These human mAbs hold the promise for the prevention and treatment of the ongoing pandemic of COVID-19."
AUTHORS
Lilin Ye
Zhirong Li
Jianfang Tang
Xiangyu Chen
Zhaohui Qian
Yang Yang et al
PUBLISHED
2020 in Cold Spring Harbor Laboratory

Add to List
Mutated COVID-19, May Foretells Mankind in a Great Risk in the Future
"Corona virus disease 2019 SARS-CoV-2 (COVID-19) is a zoonotic virus causing a variety of severe of respiratory diseases. SARS-CoV-2 is closest to SARS-CoV and MERS-CoV in structure. The highly prevalence of COVID-19 is due to the lack onset of symptoms. Our study aimed to present an overview of the virus in terms of structure, epidemiology, symptoms, treatment, and prevention. Conduct the differences of whole genome sequence and some viral proteins to determine the gap and the change alternation of nucleotides and amino acids sequences. We evaluate 11 complete genome sequence of different coronavirus using BAST and MAFFT software. We also selected 7 types of structural proteins. We were conclude that COVID-19 might be created new mutations specifically in glycoproteins hence requires caution and complete preparation by health authorities."
AUTHOR
Ali A. Dawood
PUBLISHED
2020 in New Microbes and New Infections

Add to List
Transmission routes of 2019-nCoV and controls in dental practice
FUNDERS
Emergency Project of Sichuan University
"A novel β-coronavirus (2019-nCoV) caused severe and even fetal pneumonia explored in a seafood market of Wuhan city, Hubei province, China, and rapidly spread to other provinces of China and other countries. The 2019-nCoV was different from SARS-CoV, but shared the same host receptor the human angiotensin-converting enzyme 2 (ACE2). The natural host of 2019-nCoV may be the bat Rhinolophus affinis as 2019-nCoV showed 96.2% of whole-genome identity to BatCoV RaTG13. The person-to-person transmission routes of 2019-nCoV included direct transmission, such as cough, sneeze, droplet inhalation transmission, and contact transmission, such as the contact with oral, nasal, and eye mucous membranes. 2019-nCoV can also be transmitted through the saliva, and the fetal-oral routes may also be a potential person-to-person transmission route. The participants in dental practice expose to tremendous risk of 2019-nCoV infection due to the face-to-face communication and the exposure to saliva, blood, and other body fluids, and the handling of sharp instruments. Dental professionals play great roles in preventing the transmission of 2019-nCoV. Here we recommend the infection control measures during dental practice to block the person-to-person transmission routes in dental clinics and hospitals."
AUTHORS
Lei Cheng
Xuedong Zhou
Biao Ren
Xian Peng
Xin Xu
Yuqing Li
PUBLISHED
2020 in International journal of oral science

Add to List
Saliva: potential diagnostic value and transmission of 2019-nCoV
FUNDERS
China Postdoctoral Science Foundation , Covidien , Special Funds for Prevention and Control of COVID-19 of Sichuan University
"2019-nCoV epidemic was firstly reported at late December of 2019 and has caused a global outbreak of COVID-19 now. Saliva, a biofluid largely generated from salivary glands in oral cavity, has been reported 2019-nCoV nucleic acid positive. Besides lungs, salivary glands and tongue are possibly another hosts of 2019-nCoV due to expression of ACE2. Close contact or short-range transmission of infectious saliva droplets is a primary mode for 2019-nCoV to disseminate as claimed by WHO, while long-distance saliva aerosol transmission is highly environment dependent within indoor space with aerosol-generating procedures such as dental practice. So far, no direct evidence has been found that 2019-nCoV is vital in air flow for long time. Therefore, to prevent formation of infectious saliva droplets, to thoroughly disinfect indoor air and to block acquisition of saliva droplets could slow down 2019-nCoV dissemination. This review summarizes diagnostic value of saliva for 2019-nCoV, possibly direct invasion into oral tissues, and close contact transmission of 2019-nCoV by saliva droplets, expecting to contribute to 2019-nCoV epidemic control."
AUTHORS
Quan Yuan
Xuedong Zhou
Xiaobo Duan
Bomiao Cui
Ruoshi Xu
Ping Zhang
PUBLISHED
2020 in International journal of oral science

Add to List

QUESTIONS TO CONSIDER
Are cloth masks as effective as surgical masks at reducing the risk of contracting viruses that cause respiratory disease?
6 studies
Submitted by: MChoi 148

Do adults get sick from COVID-19 more often than children?
10 studies
Submitted by: JLjilijana 85

Do cloth masks reduce the risk of contracting viruses that cause respiratory disease?
5 studies
Submitted by: JAloni 111

Does air pollution accelerate the spread of COVID-19?
5 studies
Submitted by: JLjilijana 85

Does air pollution increase the severity of symptoms from COVID-19?
6 studies
Submitted by: KKrista 83

Does a surgical (non-N95) mask reduce the risk of contracting viruses that cause respiratory disease?
23 studies
Submitted by: ELee 65

Add question
What additional question do you want someone who searches for "Does an N95 mask reduce the risk of contracting viruses that cause respiratory disease better than a surgical mask" to consider?