Face Masks Can Protect You
The spreading of the current COVID-19 pandemic is incredibly fast – by April 21st, over 2500000 people have been infected, and the virus has spread to almost every country in the world. Not only does the virus pose a considerable threat to every people, but the virus also threats the healthcare system of every country by overwhelming the system. During the pandemic, for all the people, knowing how to protect themselves from getting infected is a significant concern for them. Now the problem is that wearing face masks, which is one of the most useful ways of protecting people from getting the virus, is still doubtful and exceptionable for some people. The reason why I am writing this article is to promote the importance of mask-wearing during the pandemic, especially for respiratory infectious diseases. Thankfully, wearing face masks, including cloth face coverings, is now recommended by many governments. However, about one month ago, face masks were not supported in the United States, while face masks were commonly used in Asian countries, such as China, Korea, and Japan. Therefore, most people in the United States do not know the importance of wearing masks until recently. Moreover, some people were being averse to and even discriminating against people who wear a mask. As a matter of fact, recent studies have showcased that wearing face masks in public places can significantly reduce the risk of getting infected and infecting other people.
Transmission Mode
To begin with, understanding the transmission mode of the disease plays a vital role in analyzing the effectiveness of face masks. According to the WHO and CDC, it is inevitable that the coronavirus can be transmitted through droplets of different sizes (usually >5μm), and airborne transmission of the virus is still controversial and uncertain. According to WHO, Droplet transmission occurs when a person is in close contact (within 1 m) with someone who has respiratory symptoms (e.g., coughing or sneezing) and is therefore at risk of having his/her mucosae (mouth and nose) or conjunctiva (eyes) exposed to potentially infective respiratory droplets.
On the other hand, Airborne transmission refers to situations where droplet nuclei (residue from evaporated droplets and generally considered to be particle <5μm in diameter) or dust particles containing microorganisms can remain suspended in the air for long periods of time and transmit to others over distances greater than 1m. Therefore, the transmission of the COVID-19 virus can occur by direct contact with infected people and indirect contact with surfaces in the immediate environment or with objects used on the infected person (e.g., stethoscope or thermometer).
Recently, more and more studies indicate the existence of airborne transmission. According to Harvey Fineberg, who heads a standing committee on Emerging Infectious Diseases and 21st Century Health Threats, and his National Academy of Sciences (NAS) colleagues, the novel coronavirus can spread through the air—not just through the large droplets emitted in a cough or sneeze. Though current studies aren’t conclusive and complete, “the results of available studies are consistent with aerosolization of virus from normal breathing,” Harvy Fineberg wrote in a letter to Kelvin Droegemeier, head of the White House Office of Science and Technology Policy. Therefore, even though the airborne transmission of COVID-19 is still uncertain, we should not neglect the existence of airborne transmission showcased by recent studies because the consequence is severe and unaffordable for the healthcare systems of countries all over the world.
Different Types of Mask and Effectiveness to Each
When talking about the effectiveness of face masks, different types of face masks need to be mentioned: the homemade mask (made of four-layer kitchen paper and one-layer cloth), surgical (medical mask), and N95 respirator. Different face masks’ effectiveness in blocking the virus is different. A recent study conducted by Qing-Xia Ma, Hu Shan, Hong-Liang Zhang, Gui-Mei Li, Rui-Mei Yang, and Ji-Ming Chen indicates that N95 masks, medical masks, and homemade masks made of four-layer kitchen paper and one-layer cloth could block 99.98%, 97.14%, and 95.15% of the virus in aerosols, respectively. In their study, we evaluated the effectiveness of three types of masks in blocking the avian influenza virus (AIV) in aerosols. It is appropriate to utilize AIV to mock SARS-CoV-2, which is the virus that causes COVID-19, because both viruses have similar properties, such as shape and diameter.
This study showcases that N95 respirator could block nearly all the mock virus. Because of this, N95 respirators are commonly used in hospital environments that are contaminated by the virus. Medical masks blocked approximately 97% of the virus. Hence, though medical masks are not adequately protected in hospital environments, they are suitable for casual social occasions because they can significantly reduce the risk of inhaling the virus. When medical masks are in shortage, the homemade masks made of four-layer kitchen paper (each layer contains three thin coats) and one layer of polyester cloth should be helpful, as indicated by this study. Also, the process of producing a homemade mask is simple, and the materials are common for ordinary people.
However, it is worth noting that the homemade masks shall be of less blocking efficacy if made of fewer layers of kitchen paper. Other types of homemade masks, especially those made of cloth alone, may be unable to block the virus and thus confer no protection against the infection. The experiment was only performed 100 times, and therefore, some people may question the accuracy of the investigation. However, although a person inhales much more than 100 times a day, the mocking data are reliable because aerosols containing the virus to be inhaled by a person on most common social occasions are fewer than in this experiment.
The Case for Masks
While vital Western institutions such as Food and Drug Administration (FDA), Center for Disease Control and Surgeon general in the United States and many other public health agencies in the west advise the general public against donning of surgical or N95, Eastern countries have strongly advocated for their uses, and it is evident they are somehow successfully starting to contain the novel virus. Besides, many other regions that have effectively subdued the incidence rate of the virus infections have embedded the cultures of wearing masks except for Germany, where they had implemented the early and excellent testing protocols to break the chain of the infection quickly.
China, South Korea, Hong-Kong, and Japan all embraced various degrees of austerity in encouraging widespread use of masks more so for individuals likely involve in interpersonal contacts (“What is the evidence on wearing masks to stop COVID-19?”, 2020). Notwithstanding, additional strategies such as mass testing, active contact tracing, and necessary social distancing have also been embraced in all of these countries to manage the risk effectively. Cities that have not effectively managed the risk, such as Milan and New York, have not adopted the widespread wearing of masks. However, although it is imperatively not possible to conclusively attribute the differences in outcomes to the extensive use of masks, we should reconsider its effectiveness as an intervention.
Additionally, to the anecdotal observations, several scientific types of research show the use of masks reduces the risk of respiratory infection in healthcare workers. For example, Meta-analyses showed that N95 respirators and surgical masks were the most consistent and comprehensive supportive measures in reducing the risk of COVID-19 infection among healthcare workers. Most such researches are observational in nature, and naturally, we should request a Randomized Controlled Trial (RCT) to be the primary arbiter of this debate. Fortunately, there exist RCTs on the usage of masks as some were indeed conducted in 2008 to examine the use of masks in a household to prevent respiratory virus transmission. The study concludes with an eighty percent reduction in contracting respiratory illness among compliant patients.
What Should We Aim For?
Eventually, we must reflect on key global outcomes of what we are pursuing. If we are aiming to contain the pandemic, the primary goal of any intervention should be to bring R0, the number of people that can be infected by one infected person, to less than one, suggesting that the infection rate will not grow exponentially anymore. The use of masks has a compelling effect in that it will protect both an individual from transmitting and getting exposed to the virus. The impact of this could be a tremendous reduction in RO. Assuming that masks are 80 Percent effective in spreading the spread of the novel coronavirus on an individual basis, then the overall risk reduction in a single interaction between two people should be 96 percent. Additionally, if we are more conservative and assume that low compliance mask quality reduces individual risk by 50 percent instead, then the overall risk reduction within a single interaction between two people will be 75 percent.
If RO is estimated to be 4, and we all practice the existing risk mitigation methodologies, including social distancing and hand hygiene besides wearing masks, it is highly possible that RO will be reduced to less than 1. Any intervention effort that brings down RO to less than 1 is the difference between the unconstrained growth and eventually stopping the spread of the virus. Therefore, this should be a though consideration.
I support and recognize the WHO, CDC, and other vital institutional leaders that are heroically leading the fight against COVID-19 and invite all stakeholders to acknowledge if there are any dubious benefits to the widespread use of masks, all the considerations are merited. Additionally, the general low-risk nature associate with this intervention, scientific and anecdotal evidence that surrounds their extensive use, is actually a cause for pause. Therefore, our thoughts for their use in this fight should be subjected to sober and subjective scrutiny. Probably, this could very well be the proverbial little hinge that swings the big door in the battle for humanity.
References
“Modes of transmission of the virus causing COVID-19: implications for IPC precaution recommendations” by WHO: https://www.who.int/news-room/commentaries/detail/modes-of-transmission-of-virus-causing-covid-19-implications-for-ipc-precaution-recommendations
The peer-reviewed article “Potential Utilities of Mask Wearing and Instant Hand Hygiene for Fighting SARS-CoV-2” by Qing-Xia Ma et al.
Singhal, T. (2020). A review of coronavirus disease-2019 (COVID-19). The Indian Journal of Pediatrics, 1-6.
“Use of Cloth Face Coverings to Help Slow the Spread of COVID-19” by CDC: https://www.cdc.gov/coronavirus/2019-ncov/prevent-getting-sick/diy-cloth-face-coverings.html
What is the evidence on wearing masks to stop COVID-19?. (2020). Retrieved May 3rd, 2020, from https://www.weforum.org/agenda/2020/04/should-we-be-promoting-the-widespread-use-of-masks/
“You may be able to spread coronavirus just by breathing, a new report finds” by Robert F. Service: https://www.sciencemag.org/news/2020/04/you-may-be-able-spread-coronavirus-just-breathing-new-report-finds
Zhong, B. L., Luo, W., Li, H. M., Zhang, Q. Q., Liu, X. G., Li, W. T., & Li, Y. (2020). Knowledge, attitudes, and practices towards COVID-19 among Chinese residents during the rapid rise period of the COVID-19 outbreak: a quick online cross-sectional survey. International Journal of Biological Sciences, 16(10), 1745.