The coronavirus disease (COVID-19) has left many countries grappling with high infection rates. The novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has negatively impacted societies and economies. Now though, many countries are starting to lift restrictions to prepare for a "new normal."
As the world slowly switches to a more cautious way of living, many Governments are advising residents to maintain some of the COVID-19 preventative measures. These include the wearing of facemasks in public, maintaining social distancing, maintaining proper hand and cough/sneeze hygiene, staying at home when unwell, and getting tested if showing respiratory symptoms or a fever.
Why universal masking?
Countries who fought the coronavirus and effectively "flattened the curve" had one thing in common – they all advised their residents to wear facemasks in public places and to social and physical distance from anyone outside of their immediate family. These measures have shown to be effective in reducing the transmission of SARS-CoV-2.
A new study by researchers at the University of Cambridge illustrates how important it is to use facemasks. They found that if 100 percent of people wore masks all the time in public, combined with lockdowns and social distancing measures, it could help stem the spread of the virus.
In the modeling study, described in the Proceedings of the Royal Society A, the study highlights the population-wide use of facemasks. Facemasks keep the coronavirus reproduction number or R0, the rate at which a single infected person infects secondary individuals, under 1.0. This means that wearing face masks could prevent a second wave of the virus from hitting during the 18 months that experts say it will take to have a vaccine ready.
"Our analyses support the immediate and universal adoption of facemasks by the public," Dr. Richard Stutt, part of a team that usually models the spread of crop diseases at Cambridge's Department of Plant Sciences and lead author of the study.
"If widespread facemask use by the public is combined with physical distancing and some lockdown, it may offer an acceptable way of managing the pandemic and re-opening economic activity long before there is a working vaccine," he added.
The study also found that if 50 percent of the population or more wear masks in public, it can reduce the COVID-19 spread to a reproduction number less than 1.0, which could help flatten the disease wave.
The modeling study also advocated that the sooner a policy of total facemask adoption is imposed, the better.
What masks to use?
The team investigated the varying effectiveness of facemasks. In a previous study, it showed that even homemade masks, which were made from cotton t-shorts or dishcloths could provide 90 percent protection.
The study also implies that if the entire population wear masks that provide 75 percent protection, it can still bring a high reproduction number of 4.0 to under 1.0, even without strict lockdowns.
"Our analysis indicates that a high proportion of the population would need to wear facemasks to achieve a reasonable impact of the intervention. In Hong Kong, 99% of survey respondents reported wearing facemasks when outside of their home," the researchers wrote in the paper.
The team also emphasized that homemade masks could capture large droplets of the virus. The larger the droplets, the more critical it is to capture them, and homemade masks can do this very well. Homemade masks reduce disease spread by catching the wearer's virus particles, while inhaled air is breathed in from around the exposed sides of the mask.
In another study, evidence shows that cloth masks, specifically those with several layers of cotton cloth, can block droplet and airborne transmission of COVID-19. A mask made of three layers of fabric – muslin, flannel, and muslin, reduced surface contamination by as much as 99 percent, total airborne pathogens by 99 percent, and bacteria by 88 to 99 percent.
A single-layered mask may provide 10 to 40 percent protection, but adding more layers may improve efficiency.
The U.S. Centers for Disease Control and Prevention (CDC) recommends that people should use simple cloth face coverings to slow the spread of the virus. Asymptomatic and presymptomatic people may transmit the virus and do not know it. Cloth face coverings, even those made from homemade items from everyday materials, can be used as a public health measure.
The CDC also recommends that people use homemade masks instead of surgical masks or N-95 respirators because those are critical supplies that should be reserved for health care workers and medical responders.
Western countries may have a hard time imposing universal masking. People often have the notion that if they wear a facemask, they consider others as a threat.
"There is a common perception that wearing a facemask means you consider others a danger. In fact, by wearing a facemask, you are primarily protecting others from yourself. Cultural and even political issues may stop people wearing facemasks, so the message needs to be clear: my mask protects you, your mask protects me," Professor John Colvin, coauthor from the University of Greenwich," said.
"In the U.K., the approach to facemasks should go further than just public transport. The most effective way to restart daily life is to encourage everyone to wear some kind of mask whenever they are in public," Colvin added.
How to make an easy, no-sew face mask
- Stutt, R., Retkure, R., Bradley, M., Gilligan, C., and Colvin, J. (2020). A modelling framework to assess the likely effectiveness of facemasks in combination with 'lockdown' in managing the COVID-19 pandemic. Proceedings of the Royal Society A. https://royalsocietypublishing.org/doi/10.1098/rspa.2020.0376