Coronavirus disease (COVID-19) technical guidance by WHO Advice on the use of masks in the community

Advice on the use of masks in the community, during home
care, and in health care settings in the context of COVID-19.
Interim guidance
19 March 2020
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Background
This document provides rapid advice on the use of medical
masks in communities, at home, and in health care facilities
in areas that have reported outbreaks of COVID-19. It is
intended for public health and infection prevention and
control (IPC) professionals, health care managers, health care
workers, and community health workers. It will be revised as
more data become available.

cover their nose and mouth with a bent elbow or paper
tissue if coughing or sneezing, dispose of the tissue
immediately after use, and perform hand hygiene;
refrain from touching their mouth and nose.
A medical mask is not required for people who are not sick
as there is no evidence of its usefulness in protecting them.
However, masks might be worn in some countries, in
accordance with local cultural habits. If masks are used, best
practices should be followed about how to wear, remove, and
dispose of them, and for hand hygiene after removal.
Current information suggests that the route of
human-to-human transmission of COVID-19 is either via
respiratory droplets or contact. Any person who is within
1 metre (in close contact) of someone who has respiratory
symptoms (e.g. sneezing, coughing, etc.) is at risk of being
exposed to potentially infective respiratory droplets.
Individuals with respiratory symptoms should:

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Medical masks are surgical or procedure masks that are flat
or pleated (some are shaped like cups); they are affixed to the
head with straps.
wear a medical mask and seek medical care as soon as
possible if they have fever, cough, and difficulty
breathing;
follow the advice below regarding appropriate mask
management.
Home care
General advice
WHO recommends that all laboratory confirmed cases be
isolated and cared for in a health care facility. WHO
recommends that all persons with suspected COVID-19 who
have severe acute respiratory infection be triaged at the first
point of contact with the health care system and that
emergency treatment should be started based on disease
severity. WHO has updated treatment guidelines for patients
with ARI associated with COVID-19, which includes
guidance for vulnerable populations (e.g., older adults,
pregnant women and children). In situations where isolation
in a health care facility of all cases is not possible, WHO
emphasizes the prioritization of those with highest probability
of poor outcomes: patients with severe and critical illness and
those with mild disease and risk for poor outcome (age >60
years, cases with underlying co-morbidities, e.g., chronic
cardiovascular disease, chronic respiratory disease, diabetes,
cancer).
Wearing a medical mask is one of the prevention measures
that can limit the spread of certain respiratory diseases,
including COVID-19. However, the use of a mask alone is
insufficient to provide an adequate level of protection, and
other measures should also be adopted. If masks are used,
they must be combined with hand hygiene and other
IPC measures to prevent human-to-human transmission of
COVID-19. WHO has developed guidance for home care 1
and health care settings 2 on IPC strategies for use when
COVID-19 is suspected.
Wearing medical masks when not indicated may result in
unnecessary costs and procurement burdens and create a false
sense of security that can lead to the neglect of other essential
measures, such as hand hygiene practices. Further, using a
mask incorrectly may hamper its effectiveness in reducing the
risk of transmission.
If all mild cases cannot be isolated in health facilities, then
those with mild illness and no risk factors may need to be
isolated in non-traditional facilities, such as repurposed hotels,
stadiums or gymnasiums where they can remain until their
symptoms resolve and laboratory tests for COVID-19 virus
are negative. Alternatively, patients with mild disease and no
risk factors can be managed at home. Home care may also be
considered when inpatient care is unavailable or unsafe (e.g.
capacity is limited, and resources are unable to meet the
demand for health care services).
Community settings
Individuals without respiratory symptoms should:
 avoid groups of people and enclosed, crowded spaces;
 maintain distance of at least 1 meter from any person
with respiratory symptoms (e.g. coughing, sneezing);
 perform hand hygiene frequently, using an alcohol-based
hand rub if hands are not visibly dirty or soap and water
when hands are visibly dirty;
Specific IPC guidance for home care should be followed.
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