Protection From COVID-19The Efficacy of Face Masks.
Dtsch Arztebl Int
; 118(5): 59-65, 2021 02 05.
Article
in English
| MEDLINE | ID: covidwho-1159700
ABSTRACT
BACKGROUND:
Since the beginning of 2020 the SARS-CoV-2 virus has spread to nearly every country in the world. The mainly airborne pathogen has led to large numbers of deaths, principally in elderly and vulnerable segments of the population. Protective vaccines have recently become available, but it is not yet clear whether and when population-wide immunity will be achieved. The existence of evidence for the protective effect of masks covering the mouth and nose is a topic of public debate.METHODS:
A selective literature search was carried out in PubMed. Data from the German Robert Koch Institute and the Centers for Disease Control and Prevention were also taken into account.RESULTS:
When talking, as many as 20 000 droplets ranging in size from 20 to 500 µM are released every second. According to PCR tests, the amount of virus exhaled is highest immediately before the onset of symptoms. No randomized trials have been conducted on the effect of masks covering the mouth and nose. A metaanalysis of 29 studies on infection with SARS-CoV-2, SARS, or MERS revealed that type N-95 masks (corresponding approximately to FFP-2), surgical masks, or similar multilayer cotton masks can greatly reduce the infection risk for the wearers (RR 0.34 [0.26; 0.45], with moderate heterogeneity [I2 = 48%]). Model experiments and case reports suggest that masks covering the mouth and nose afford considerable protection against transmission of SARS-CoV-2 and other airborne diseases by reducing release of and exposure to potentially infectious droplets; in addition, infections that do occur take a milder course. A limitation of the studies analyzed is that in most cases, this effect cannot be viewed in isolation from the protective impact of other measures (distancing, hygiene precautions).CONCLUSION:
It can plausibly be assumed that consistent use of masks covering the mouth and nose can play an important role in containing the spread of SARSCoV- 2.
Full text:
Available
Collection:
International databases
Database:
MEDLINE
Main subject:
COVID-19
Type of study:
Experimental Studies
/
Observational study
/
Prognostic study
/
Randomized controlled trials
/
Reviews
Topics:
Vaccines
Limits:
Aged
/
Humans
Country/Region as subject:
North America
Language:
English
Journal:
Dtsch Arztebl Int
Journal subject:
Medicine
/
Public Health
Year:
2021
Document Type:
Article
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