Current information suggests that there are the two main routes of transmission of the COVID-19 virus, namely by respiratory droplets (generated when an infected person coughs or sneezes) and contact. Any person who is in close contact (within 1 m) with someone who has respiratory symptoms (coughing, sneezing) is at risk of being exposed to the virus. Droplets may also land on surfaces where the virus could remain viable; therefore, the environment of an infected individual may also be a source of transmission.
WHO convenes global teams of experts that review the latest studies and participate in weekly advisory calls to help inform guidance documents. Advice on the use of masks has been changing constantly based on emerging evidence.
Why do we use masks?
- prevent the wearer transmitting infection to others (source control) or
- protect to the wearer against infection (prevention).
Points that should be considered when identifying the correct mask to be worn include:
Risk of exposure to COVID-19
- When there is high viral transmission within the community and other measures, such as contact tracing or the ability to swab, are not possible.
- Based on occupation, for example when individuals work in close contact with the public
Vulnerability of the mask wearer/population:
If supplies are adequate, medical masks could be used by people who are more vulnerable such as older people or those who are immuno-compromised.
The setting in which the population lives:
Settings with high population density (e.g. refugee camps, those living in cramped conditions) and where individuals are unable to maintain recommended physical distancing (e.g. crowded buses or supermarkets etc.)
- Availability and cost of masks
- Access to clean water to wash non-medical masks
- Ability of mask wearers to tolerate the adverse effects of wearing a mask.
It is important to note that are a number of potential risks and disadvantages to be considered on the use of masks:
Factors to consider (based on type of mask used) include overall discomfort with prolonged use that can cause facial skin breakdown, difficulty with communicating clearly and in some cases difficulty in breathing.
Non-medical masks/ cloth face coverings
There is an increased risk of infecting a person if the mask is contaminated by dirty hands and touched often, or kept on other parts of the face or head and then placed back over the mouth and nose
In addition, it is possible that mask-use, could create a false sense of security in the wearer, leading to negligence to observe other beneficial preventive measures such as physical distancing and hand hygiene.
- For information on the types of masks, click here.
- For information on the use of medical masks, click here.
- For information on management of masks/face coverings, click here.
- For information on how to make a fabric face covering, download the ‘Face Covering’ resources on this page or read more from PHE or the CDC.
- For the latest WHO guidance on the use of masks during COVID-19, click here.
WHO highlights that wearing a mask does not dimish the need for regular hand hygiene and observance of physical distancing wherever possible; and that if you do use a mask, you must know how to use it and dispose of it properly.