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COVID-19
PANDEMIC

Cloth Masks:

Public Defense

Against COVID-19

Disease

By John Menchaca, MD

In December 2019, a novel form of the coronavirus family was
first detected in a group of residents in the city of Wuhan, China,
that initially presented with fever and cough, followed later by severe
respiratory distress. At first, these patients were thought to have had
close contact with bats that were being sold at the Hunan Seafood
Market, but Zhang et al reported that only 8 of the 221 patients
had any contact with the market. 1,2 In another report, JF-W Chan
et al reported on several family clusters in the same city to suggest There were two countries outside of China that, despite the
a human-to-human transmission. In the ensuing weeks of January paucity of evidence of masks being effective in preventing the
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and February 2020, the disease became widespread throughout transmission of the virus, chose to mandate mass cloth mask usage
many of the Asian countries and later on into European countries in public places where social spacing was not possible or practical
and the United States. – South Korea and Chechnya. On the other hand, Italy and Austria
Initial recommendations from both the World Health Organiza- chose not to mandate masks. The two countries that mandated
tion (WHO) and Centers for Diseases Control (CDC) specified only masks had dramatic lower rates of transmission. 8
social spacing (six feet), frequent hand washing and cleansing of Incorporating the basic physiological behavior of viral droplets
surfaces that might be reservoirs of the viruses. 4,5 Cloth masks, and aerosols in public places with the fact that patients who were
used by the general public at risk for the coronavirus infection, were already infected but not showing any signs of disease may be already
discouraged because they were thought to be ineffective in prevent- shedding the viruses by their simply breathing without coughing or
ing the spread of the virus. In addition to the absence of controlled sneezing, brings up a very difficult disease management dilemma;
studies to evaluate the effectiveness of the masks, two other argu- how to manage these asymptomatic patients? Extensive testing and
ments were mentioned; usage of the masks would compromise the contact tracing only symptomatic patients will obviously miss many
already inadequate supply for healthcare personnel and, there were of the asymptomatic ones who are just as infectious as the symp-
a few studies on masks that suggested only a marginal effect on the tomatic ones.
transmission rates of avian and seasonal influenza and obviously The obvious solution is to consider universal, general public mask
none for the COVID-19 virus. usage when in public places. Cloth masks worn by infected persons,
During the early weeks of the pandemic, there were two studies asymptomatic or symptomatic, will trap the droplets before they are
that further complicated the original recommendations of social released into the immediate air space, thereby preventing the virus
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spacing and handwashing. 6,7 Bourouiba, et al, demonstrated that from spreading any further. Greenhalgh, et al, further expounded
droplets and aerosols (dried airborne residues from the droplets), on the “precautionary principle” that in the absence of definitive
produced by coughing and sneezing, could actually travel as far as results from controlled studies and the fact that we are dealing with
twenty five feet. Furthermore, they showed that the aerosols may a very dangerous illness, it is reasonable to proceed with universal
persist in the air for two-to-three hours, especially in areas with poor usage of masks to prevent the spread of COVID-19 infections. In
air circulation. their most recent updates, both the World Health Organization and

16 San Antonio Medicine • June 2020