Masks - to wear or not to wear
By Tanya Waterworth, Independent on Saturday, article published Apr 4, 2020
Executive director of WHO health emergencies programme, Dr Mike Ryan, said at a press briefing on Monday 'there is no specific evidence to suggest the wearing of masks by the mass population has any potential benefit', adding the global shortage of masks was putting front-line healthcare workers at high risk.
'The thought of them not having masks is horrific,' he said.
Also this week, South Africa's Minister of Health, Dr Zweli Mkhize, recommended the wearing of masks, saying 'we recommend them particularly where people have any cough or any symptoms in a situation where social distancing is difficult'.
Infectious disease specialist on the University of KwaZulu-Natal Covid-19 War Room team, Dr Richard Lessells, said when it came to masks, it was important to differentiate between an infected person or potentially infected person wearing a mask to prevent the spread, compared with a healthy person using a mask to protect themselves from being exposed to the virus.
'When members of the public think about wearing a mask, they think it's to protect themselves, but actually it will mostly be for other people's benefit. If they happen to have Covid-19 and are infectious (even if they don't have symptoms) then wearing a mask may limit the spread to other people.'
'The mask is just acting as a physical barrier to the droplets (tiny spatters of water) that come out of our mouth and nose when we cough, sneeze, talk and just breathe - the droplets will be captured on the internal surface of the mask and not get through.'
'The mask acts in the same way as covering your mouth and nose with a tissue or with your elbow, but it's on all the time. This essentially reduces the exposure of people around that infected person whose droplets might be carrying the virus.'
Lessells said the second option of using a mask to protect the wearer from being exposed to the virus should be focused on health workers because they will have close contact with people who have or may have Covid-19.
In public areas, social distancing should reduce close contact.
He said healthcare workers should be wearing either surgical masks or N95 masks (the N95 masks are designed with a special filter). Which mask they should wear depends on the area in which they are working, how long they will be in close contact with patients, and the procedures they might be doing.
'Both the surgical and N95 masks act as a physical barrier to the larger droplets,' he said, adding that specialised N95 masks were used when doing medical procedures where aerosols (smaller particles from the respiratory tract) are generated.
'An example of such a medical procedure would be an intubation, when a tube is placed down the back of the throat into the lungs and connected to a ventilator for the patient to be able to breathe. Such a procedure would be carried out by medical personnel, such as anaesthetists and critical care specialists, who would be looking after the most serious cases and doing many of the procedures which carry the most risk. An N95 mask also has to be fitted correctly, sealing the face to be effective, and close attention has to be paid as to how it is removed to avoid contamination of hands during the process.'
Lessells said: 'There is a huge focus on the masks. It's a very emotive issue and there is understandably a lot of fear, particularly among healthcare workers'.
'But it is important to remember that masks are only one component of how we prevent the spread of the virus, particularly in healthcare settings,' he said, adding that personal protective equipment also includes aprons or gowns, eye protection and gloves, and infection prevention and control includes many other components such as hand hygiene, cough hygiene, separation of patients, and adequate ventilation.'
He stressed that for the general public and health workers, 'hand hygiene remains the most important prevention method'.
With regard to South Africa, Lessells also pointed out that the country's health system was also dealing with other respiratory infections such as tuberculosis (TB).
On World TB Day on March 24, the WHO said: 'As we mark World TB Day 2020, the disease remains the world's top infectious killer.'
'In 2018, 10million people fell ill with TB worldwide and 1.5million people lost their lives.'
The University of the Western Cape also released a statement on World TB Day, describing TB as one of the leading causes of death in South Africa, with more than 300000 people contracting the disease each year, with an average of 180 deaths a day.
Lessells said: 'Some of the panic now around Covid-19 is highlighting that in many places we weren't doing what we should have been doing to prevent the spread of TB in health facilities and in the community.
"The initiatives we are now rushing to introduce are things we should be doing already - screening people at entry to health facilities for cough, giving surgical masks to anyone who's coughing and masks for healthcare workers if working in an area where they are exposed to people with TB or people being investigated for TB.'
The Independent on Saturday
News date: 2020-04-04