Why everyone should wear masks

The pandemic can be slowed only by a lockdown as well as by ensuring universal mask use

06/04/2020, T. JACOB JOHN

Flattening the epidemic curve (case distribution curve) is the need of the day. On the curve, Y axis and X axis represent case numbers and time, respectively. A normal epidemic curve is bell-shaped, with an early ascending slope (first phase), a peak (second phase) and a declining slope (third phase). The area under the curve represents the total number of cases. India is now in the first phase of the COVID-19 pandemic.

A rapid increase in cases will demand far more healthcare facilities than now available. Healthcare facilities were not created in anticipation of a pandemic and are grossly inadequate for India to tackle the first phase. A flattening of the curve will reduce the demand on beds in intensive care units, respirators, and specialists to manage acute respiratory distress syndrome. The peak will be dwarfed and come after some breathing time; the pressure will be eased. However, the area under the curve, the total number of cases, whether the curve is bell-shaped or flattened, will be the same. This crucial information in the epidemiology of the epidemic must be taken into account for planning a response.

Flattening the curve

There are two ways of flattening the curve: imposing a strict lockdown for a number of weeks or use of face masks all the time when outside our homes. A lockdown physically distances families from each other. The disadvantage is that family members may not be able to keep a physical distance of two metres from one another all the time. As a result, intra-familial spread occurs and more people are infected at the end of the lockdown than at the beginning. But during a lockdown community transmission is prevented.

There are four reasons for the universal use of masks. First, any infected person will not infect others because the droplets of fluids that we let out during conversations, coughing or sneezing will be blocked by the mask. Remember, most infectious people don’t have symptoms, or have mild symptoms, and are unaware that they are infected. Second, uninfected people will have some protection from droplet infection during interactions with others. For those who wear eyeglasses, there is additional protection from droplets falling on the conjunctiva. When both parties wear masks, the probability of transmission is virtually zero. Third, the mask-wearers will avoid inserting their fingertips into their nostrils or mouths. Viruses deposited on surfaces may be carried by hand if we touch such surfaces; if we do not touch our eyes, nostrils or mouth, this mode of transmission is prevented. Fourth, everyone will be reminded all the time that these are abnormal days.

In overcrowded areas such as slums, a lockdown will not be efficient in slowing down transmission. In such places, universal mask use is a simple way to slow down transmission. In India the wise choice would have been to ensure universal mask use in slums, bazaars, shops selling essential commodities, etc. before the lockdown. But then, wisdom, proverbially, is slower than adventure.

Making your own mask

Taiwan and the Czech Republic depended primarily on universal mask use and slowed down the epidemic. In the Czech Republic, people made their own masks. Cotton pieces, preferably coarse, three layers, stitched with two straps, make masks of sufficient quality. These masks should cover the nose from just below the eye level and reach and cover the chin. All adults, and children who are old enough to wear masks, should wear them. At the end of the day, cotton masks can be washed in soapy water and hung to dry for re-use.

COVID-19 mortality is due to three reasons. Virus virulence is the given and cannot be altered. Co-morbidity (diabetes, chronic diseases) is already prevalent. Then there is low-quality healthcare. Slowing down the epidemic by imposing a lockdown and ensuring universal mask use gives us the chance to protect people from infection and improve healthcare quality; wherever that was done, the mortality was less than 1%.

T. Jacob John is retired Professor of Virology in the Christian Medical College, Vellore