Shaheen Mehtar, Stellenbosch University; Lucille Blumberg, University of the Witwatersrand, and Marc Mendelson, University of Cape Town

Many countries, including South Africa and Nigeria in Africa, are moving to make it mandatory to wear non-medical cloth masks when people are outside their homes. The move is seen as a vital additional measure to prevent the spread of SARS-CoV-2, the novel coronavirus causing COVID-19.

Wearing cloth masks is being introduced in conjunction with maintaining a physical distance of at least 1.5 metres and strictly following hygiene measures such as hand washing, good cough etiquette, and decontamination of regularly used surfaces.

Medical face masks have been a vital part of COVID-19 prevention efforts in East Asian countries such as China, Taiwan, Hong Kong and South Korea.

In countries where medical face masks are preserved for healthcare workers or are scarce, fabric face masks provide a cost-effective alternative. These can be homemade and are reusable.

There has been a growing movement of homemade mask production. Factories have also repurposed to produce fabric face masks to support commercial and free distribution.

In South Africa wearing a cloth mask in public places is now mandatory. In our view, there is sufficient evidence to suggest if everyone wears a mask, droplet transmission from each person will reduce and minimise exposure.

Transmission

The early phases of the COVID-19 epidemic included an evolving understanding of the routes of transmission of the coronavirus. It is now well established that droplet transmission is of vital concern. In the case of the severe acute respiratory syndrome coronavirus in 2002, viral shedding via the respiratory tract happened mostly after people developed symptoms. But COVID-19 includes a pre-symptomatic phase where people can be infectious and still feel healthy and be unaware that they are infected. Mildly symptomatic and asymptomatic cases also occur.

Mandatory masking ensures that viral transmission by any potential carrier is markedly reduced. It emphasises the concept of “source control”, in other words controlling the amount of a pathogen that is present in the environment. This is well expressed through the slogan: “I protect you, you protect me”. This was popularised by the #masks4all initiative, started by a group of researchers and scientists to promote the scientific evidence showing that cloth masks limit the spread of SARS-CoV-2.

An additional benefit of the ubiquitous wearing of face masks is the reduced possibility that respiratory droplets will be released to settle on surfaces – or for smaller aerosolised particles to float in the air.

For those still in doubt, we have answered some key questions to address the biggest areas of controversy:

• Why should I wear a cloth mask? To prevent potential transmission of the coronavirus that causes COVID-19 via respiratory droplets and particles released when you talk, laugh, sing, shout, cough or sneeze, or to prevent the potential inhalation virus laden particles. A cloth face mask also serves as barrier that prevents touch transfer from surfaces to your mouth and nose and a reminder not to touch other parts of your face – especially your eyes. In addition, a face mask reduces the extent to which droplets and particles end up on surfaces or float in the air.

• When should I wear a cloth mask? As a general rule, any time that you are outside your home, and especially in close contact situations such as when using public transport, shopping, working, or in any crowded setting. If a person in your household is possibly infected with coronavirus, face masks must be used when in close proximity, in conjunction with separating living quarters. Helplines and healthcare providers are good places to go for additional steps to follow.

• Can I make my cloth mask out of anything? The most effective approach is to use a thicker weave material such as cotton for the outer layer, and then to include at least two layers of softer material for comfort and additional barrier protection. Test the materials combined for breathability before sewing. There should be some resistance to airflow, but you should be able to breathe freely when using the completed mask. Fit is important to minimise air bypassing the cloth barrier via the sides. Materials used should be easily washable and heat tolerant for cleaning. Stretchy material should be avoided.

• How do I wear the mask? Never share a mask with anyone and always use a mask that is freshly cleaned. Wash or sanitise your hands before putting on the mask and when removing. Ensure that it covers the area from the top of your nose to below your chin. When you remove the mask, move your hands forward so you can fold the front over itself. Hold on the sides and place in a safe area for cleaning.

• How do I reuse a mask? A cloth mask can be washed in hot water with soap or washed in a washing machine. Iron or sun dry. You can also drop the mask into boiled water and leave to cool to a temperature that allows you to wash the mask with soap or washing detergent. Avoid harsh chemicals such as bleach as this will be toxic when wearing the mask. By having two masks available, you can wear one, and have one to wash.

Dr Warren Parker a public health communications specialist, and Dr Beth Engelbrecht from the Western Cape Department of Health contributed to this article.

Shaheen Mehtar, Infection Prevention and Control specialist, Stellenbosch University; Lucille Blumberg, Deputy Director of the National Institute for Communicable Diseases and a member of the joint staff, University of the Witwatersrand, and Marc Mendelson, Professor of Infectious Diseases, University of Cape Town

This article is republished from The Conversation under a Creative Commons license. Read the original article.