Show simple item record

[Evidence summary:] What is the evidence around the relative effectiveness of surgical masks to properly fitted respiratory protective equipment such as FFP2 and FFP3 masks against airborne droplet viruses: SARS, MERS, influenza, and SARS-CoV-2? [v1.0]

dc.contributor.authorNational Health Library & Knowledge Service (NHLKS)
dc.contributor.authorClark, Helen
dc.contributor.authorDelaunois, Isabelle
dc.contributor.authorLeen, Brendan
dc.contributor.authorMcKeown, Declan
dc.date.accessioned2020-07-28T09:57:56Z
dc.date.available2020-07-28T09:57:56Z
dc.date.issued2020-07-27
dc.identifier.urihttp://hdl.handle.net/10147/627923
dc.descriptionThis evidence summary incorporates general international guidance on the use of surgical masks and respirators; it also cites a recent evidence summary prepared by the Centre for Evidence Based Medicine (CEBM)6which was updated in April 2020 and concurs with the findings of a systematic review conducted by the Chinese Cochrane Centre1.In view of the fact that both of these papers have conducted literature searches that include previous pandemics, our summary provides references to trials and reviews published since March 2020,and which are not included in either the review by the Chinese Cochrane Centre or the CEBM summary.National guidance from the HPSC2and international guidance from theWHO3and ECDC4regarding the use of surgical masks vs respirators is mainly in agreement that surgical masks provide sufficient protection for all encounters with COVID-19 confirmed or suspected cases,and that N95 respirators should be reserved for situations that involve or may involve the generation of aerosols [aerosol generating procedures or AGPs]. The guidance from CDC differs insofar asit recommends more widespread use of N95 respirators5.However, widespread use of N95 masks may result in limited PPE for those healthcare workers exposed to AGPs.International literature is also, for the most part, in agreement with international guidance. The CEBM summary concludes that standard surgical masks are as effective as respirator masks such asN95, FFP2andFFP3 for preventing infection of healthcare workers in outbreaks of viral respiratory illnesses such as influenza, except in situations involving AGPs6.Most of the studies highlight the fact that the epidemiological study of COVID-19 is still in its infancy and there has not been sufficient time or organisational capacity to organise robust, properly constructed cohort studies. Opinions are also divided as to whether COVID-19 is preferentially spread in droplet or aerosol form, although fluid and droplet dynamic models suggest that influenza transmission models can be applied to COVID to better illustrate the dynamics of person-to-person transmission.More recent studies draw a similar conclusion, while at the same time acknowledging that although respirators may offer better protection, the evidence base is so uncertain that definitive conclusions cannot be deduced. MacIntyre et al note that although laboratory testing shows that N95 masks are superior to surgical masks, the outcomes of studies in the clinical setting show no significant difference in effect11.In summary, surgical masks, according to the available evidence, have been shown to provide similar protection against COVID-19 as N95 respirators in routine patient contact in a clinical setting. However, N95 masks are recommended for use in all procedures that risk generating aerosols due to the greater level of fit of the mask to the individual’s face:the robust barrier effectively prevents the inhalation of aerosolised secretions from an infected patient. It is important to stress at this point that the definition of an aerosol-generating procedure will differ from setting to setting and therefore there should be flexibility to allow the use of N95 masks if an individual clinician, following a clinical risk assessment, determines that there is a risk of generation of aerosol from any procedure or patient encounter.Most authors agree that more research is needed;and trials comparing the effectiveness of surgical masks vs respirators have been registered, an example of which is included below.en_US
dc.language.isoenen_US
dc.publisherHealth Service Executiveen_US
dc.relation.ispartofseriesEvidence summariesen_US
dc.subjectCORONAVIRUSen_US
dc.subjectCOVID-19en_US
dc.subjectSURGICAL MASKSen_US
dc.subjectINFECTION PREVENTION AND CONTROLen_US
dc.title[Evidence summary:] What is the evidence around the relative effectiveness of surgical masks to properly fitted respiratory protective equipment such as FFP2 and FFP3 masks against airborne droplet viruses: SARS, MERS, influenza, and SARS-CoV-2? [v1.0]en_US
dc.typeOtheren_US
refterms.dateFOA2020-07-28T09:57:56Z


Files in this item

Thumbnail
Name:
Evidence-Summary-COVID-19-Surg ...
Size:
447.1Kb
Format:
PDF
Download

This item appears in the following Collection(s)

Show simple item record