COVID-19: the Evils of Denying Preventive Effect of Face Mask


March 16,2020
Takeshi Yamasaki, D.V.M., Ph.D.
Chairman, NPO Science of Food Safety & Security

WHO (the World Health Organization) and the CDC of the United States have asserted that wearing face mask has no preventive effect on the new coronavirus infection (COVID-19).

According to the physicians who claim an expert on infectious disease even on TV wide shows and online, “Wearing face mask is a way to prevent infected people from transmitting the virus to others, and there is no preventive effect for healthy people from the COVID-19 infection. Don’t say unscientific things like virus infection prevention by wearing mask! “

You all know that Latin European countries, where no mask-wearing culture penetrated deeply, now encounter the tragedy. Thousands of people have died in Italy. Is it really okay with saying carelessly, such as “Face mask has no preventive effect”?

“WHO says that wearing face mask has no preventive effect from virus infection, and that’s why we are talking to others normally without wearing mask…” If asymptomatic infected person who looks healthy were flying saliva (so called, “virus droplet”) without wearing face mask, it might adhere to the mucous membranes of your eyes, nose and throat and you might be infected in an instant. As soon as the next person coughs, you should avoid it with an “elbow mask”. “Are you crazy? It’s IMPOSSIBLE”

Hey doctor, you say “Face mask has no preventive effect”, and always wear surgical mask for yourself when examining a patient suspected new coronavirus infection and collecting mucus for PCR tests, right? Even though you protect yourself by wearing face mask from COVID-19 infection, are you telling us not to wear mask where in the city we don’t know who the contagious people are? It’s very strange to me.

I don’t know if the passenger on the train standing in front of me is COVID-19 contagious person, how do I judge whether to wear a face mask? You should not give instructions to citizens that you cannot do.

It is said that face mask is intended to prevent others from virus infection, but it is very questionable how many asymptomatic citizens wear masks obediently. Even if the person in Gamagori-city (near Nagoya area) found PCR test positive, he intentionally spread the COVID-19 virus in the pub without wearing mask (later, he passed away). The motivation for preventive action is to protect yourself and your family from the health risk of unknown virus infection. I am afraid that humans do not move for others.

“Medical institutions and hospitals are in trouble because they do not have sufficient amount of face masks. Therefore, the general public should stop using masks for prevention.” It is a matter of course for hospitals to carry out crisis management such as backup stock of surgical masks. While we fully understand that doctors ask the health authority or local government to supply surgical masks, isn’t it strange that doctors tell citizens not to use masks. Rather, you should recommend citizens to wear face masks.

Anyway, is there any evidence that face mask has no preventive effect from the COVID-19 transmission? There must be some literature on other virus transmission such as influenza, but why can you say no preventive effect on COVID-19 by referring papers on the other virus data?

In the case of influenza, since the contact infection is often the cause, we understand that the hand washing must be much more effective than wearing a mask, where the effect of commercial masks to prevent droplet infection may not be significant. Why can you say that the new coronavirus has exactly the same form of transmission as flu?

Can you say that the contact infection is the main cause of so many virus transmissions in live music clubs? If the droplet infection is also contributing considerably, the risk reduction effect by wearing face mask should be expected to block the part where the droplet is directly sucked in your mouth and nose.

In the case of an entity that conducts business in person, if one employee becomes contagious, the history of wearing masks is checked up to two weeks in the past, so the business risk of “mask unnecessary theory” should be larger than expected.

If you tell the general public that you don’t need to wear a face mask, people may not enforce the hand-washing and disinfection. Infection prevention activities should be presented that should be simple and concise as a set of three items: 1) wear a face mask when going out, put on and take off when returning home, 2) do not touch the face by fingers until washing, 3) use a disinfectant, and so on.

It is necessary to release self-restraint of sports events and entertainment as soon as possible, so that fans / audiences should keep good manners of infection prevention. The main factor that determines the risk of infection is not the place nor the environment, but the human.

I would like to encourage citizens to practice “group prevention” proposed by Dr. Mamoru Noda in the following FAQ:

About prevention method of new type coronavirus infectious disease (COVID-19) (in Japanese)

[Copyright 2020 Takeshi Yamasaki, D.V.M., Ph.D.]