April 18 2020
When and how to wear medical masks to protect against coronavirus?
Should members of the public be wearing face masks during the COVID-19 pandemic?
The Oxford University reviewed the results of more than a dozen randomized trials of face masks and transmission of respiratory illnesses. The current best evidence suggests wearing a mask to avoid viral respiratory infections such as COVID-19 offers minimal protection, if any.
Two of the world's major health organisations disagree on mask wearing. The World Health Organisation (WHO) currently discourages mask use:
There is currently no evidence that wearing a mask (whether medical or other types) by healthy persons in the wider community setting, including universal community masking, can prevent them from infection with respiratory viruses, including COVID-19.
WHO does recommend special masks (N95 masks or equivalent) plus other protection for health-care workers working with people who have, or are suspected to have, COVID-19.
By contrast, the Centres for Disease Control and Prevention (CDC) in the United States has recently recommended everyone wear a (cloth) mask. However, this is to prevent infected people passing on the infection, not to prevent the wearer getting infected.
Recommendations:
If you are healthy, you only need to wear a mask if you are taking care of a person with COVID-19;
N95 masks useful only in intensive care when worn by health personnel;
Before putting on a mask, clean hands with alcohol-based hand rub or soap and water;
Cover mouth and nose with mask and make sure there are no gaps between your face and the mask;
Avoid touching the mask while using it; if you do, clean your hands with alcohol-based hand rub or soap and water;
Replace the mask with a new one as soon as it is damp and do not re-use single-use masks;
To remove the mask: remove it from behind (do not touch the front of mask); discard immediately in a closed bin; clean hands with alcohol-based hand rub or soap and water;
Wear a mask if you are coughing or sneezing;
Masks are effective only when used in combination with frequent hand-cleaning with alcohol-based hand rub or soap and water;
If you wear a mask, then you must know how to use it and dispose of it properly.