By Professor Dr Moy Foong Ming

This is the key question during this COVID-19 pandemic. After months the pandemic began, the public is confused if a mask is essential to keep them safe despite the World Health Organisation and the Ministry of Health Malaysia keep reiterate that people who are not sick need not wear masks. They advise that only people who are unwell or caring for the sick need to wear a mask, so that the masks can be reserved for the frontliners. Besides that, the infectious disease experts worry that masks could give people a false sense of security and make them less discipline about social distancing and hand-washing.

However, the public is not convinced with this advice. It is common to see Malaysians wearing masks in the public and some supermarkets/hypermarkets are imposing the rule that 'no mask no entry'. Recently, there are more health experts supporting the idea that face mask may be beneficial in preventing the spread of COVID-19.

COVID-19 is spread by droplet, not airborne transmission. Face masks work by stopping infected droplets spewing from the wearer's nose or mouth, rather than stopping acquisition of the virus from others. Since a COVID-19 patient may not show any symptoms and be contagious, if everyone wears a mask, the asymptomatic patient may be less likely to spread the disease to others. If everyone wears a mask, individuals protect one another, reducing overall community transmission. Places like Hongkong and Taiwan, applied social distancing and universal mask wearing early may have gotten their cases under better control. South Korea and Japan distribute masks to the public. Recently Czech Republic and Slovakia even made mask wearing mandatory. The Czech Republic has a slogan that promotes mask wearing: "my mask protects you, your mask protects me".

George Gao, the director of the Chinese Centre for Disease Control and Prevention (CDC) shares the thinking of the Czech government. He believes not wearing a mask is a big mistake. If people who are infected but asymptomatic wear a mask, it can prevent droplets that carry the virus from escaping and infecting others. Some researchers quoted that wearing mask is a perfectly good public health intervention that is not used.

Although systematic review and meta-analysis may not provide evidence on the effectiveness of face mask on flu like diseases among the public, which the included studies were mostly cluster randomized controlled trials on non COVID-19; we should observe the progress made with countries like China (including Hong Kong and Taiwan), South Korea and Japan. These countries have very proactive measures in dealing with COVID-19, and they managed to flatten the epidemic curve. These countries recommended face mask wearing among the public in areas of high population density places such as supermarket, shopping mall (China), when taking public transport or staying in crowded places (Hong Kong), or in in confined and badly ventilated spaces (Japan).

Lack of solid evidence supporting the effectiveness of masks against COVID 19 is no reason to dismiss its use, because there may never be definitive scientific proof. However, community use of masks alone is not the only method to stop the spread. Social distancing, staying home, rigorous system of contact tracing, testing and quarantine of people who are potentially infected are important steps in flattening the curve.

It is time for the government to make rational recommendations on appropriate face mask use to complement on other public health measures. Older adults and those with comorbidities, should wear masks if available. Universal use of face masks should be considered with adequate supplies. In addition, research on effectiveness of cloth face masks which is reusable after washing should be encouraged. 

(Professor Dr Moy Foong Ming is Professor in Epidemiology, Department of Social & Preventive Medicine, Faculty of Medicine, Universiti Malaya.)