As the epidemic spread, American people finally decided to wear masks.
But they are still reluctant to wear masks. Even in the beginning, they are not just unwilling, but fundamentally resist wearing masks, or even do not believe that wearing masks is useful. Even more magical, their governments, media and others are also promoting that healthy people don't have to wear masks because there is no reason why masks can reduce the spread of the new crown virus.
Today, masks have scientific evidence of a real, quantifiable reduction in the spread of the new crown virus.
Solid hammer evidence: surgical masks significantly reduce transmission of new coronavirus
On April 3, the journal Nature Medicine published an article entitled respiratory virus shielding in exhausted breath and efficacy of face masks. This article conducted a quantitative study on the protection of viruses in exhaled gas and the protection efficiency of masks.
This article was written by Benjamin cowling from the University of Hong Kong and his colleagues. The first author is Nancy H. L. Leung (N. H. L. Leung et al. NAT. Med. Https://doi.org/10.1038/s41591-020-0843-2; 2020).
specifically, the study quantified the contents of respiratory viruses (seasonal coronavirus, influenza virus, rhinovirus) in the exhaled gas of patients. it clarified that surgical masks can effectively prevent the transmission of seasonal coronavirus in respiratory droplets and provide conclusive evidence that masks prevent the transmission of SARS-CoV-2.
Article says respiratory viral infections cause widespread and similar clinical symptoms, collectively known as acute respiratory viral diseases (acute respiratory virus Illnesses,ARIs) or more common
Although it is now widely accepted that masks play an important role in cutting transmission routes and protecting susceptible populations, there is little research on the prevention and control of respiratory viruses, mainly focusing on influenza viruses
according to virology, in this study, the authors used a Gesundheit-II sampling device, which can maintain the viability of the virus in aerosols and collect the gas and cough droplets exhaled by patients within 30 minutes. The device can capture particles in the air, namely respiratory droplets (aerodynamic diameters)
In terms of research samples, 246 volunteers with respiratory diseases were divided into two groups on average: those who wore masks and those who didn't wear masks. In the exhaled gas of 111 patients, coronavirus, influenza virus and rhinovirus were detected. One person was infected with both coronavirus and influenza virus, and two people were infected with both.
The nasal swabs, throat swabs, respiratory droplets and micro aerosol particles were detected in 111 patients
Surgical masks can significantly reduce the contents of influenza virus in respiratory droplets RNA、 coronavirus RNA in aerosols, but not in nasal viruses.
more specific data show that the positive detection rate of respiratory droplet samples in patients with coronavirus without wearing masks is 30%, and the detection rate of tiny aerosol is 40%. after wearing masks, the presence of viral RNA is not detected in respiratory droplets and tiny aerosols, which indicates that wearing masks has a tendency to reduce the RNA of coronavirus in respiratory droplets.
Similarly, for influenza virus, the detection rate of respiratory droplets was 26%, and the detection rate of micro aerosols was 35%; after wearing masks, the detection rate of influenza virus in respiratory droplets was significantly reduced to 4%, but the detection rate of influenza virus in aerosols was not significantly reduced.
In addition ,5 samples of 8 patients without a mask aerosol RT-PCR tested positive for influenza virus were cultured ,4 of them positive ;4 of 6 patients without a mask aerosol RT-PCR tested positive for influenza virus were cultured and 2 were cultured positive
This result is similar to that of virus detoxification test: in short, masks can significantly reduce the amount of coronavirus in exhaled gas.
Americans are wearing masks, but they still don't pay enough attention
In fact, before the paper appeared, the blocking effect of mask on virus transmission has been recognized by many experts, and has been widely recognized. At the practical level, unlike the Chinese people who generally wear masks, Americans are very resistant to masks.
This resistance has not been eliminated, given the global spread of the epidemic.
According to a sociological study by the City University London, the Guardian reported,In western culture, there is a kind of mask phobia. They are not willing to do the simplest means of wearing masks for epidemic prevention, but they are discriminated against when people in the crowd take the initiative to wear masks.
Maskaphobia originally meant
But under the outbreak, maskphobia turned into resistance to masks.
However, in addition to the resistance of ordinary people to masks, it is surprising that in the mainstream media in the United States, there is still a fascination with masks.
For example, a New York Times article published on January 23 suggested that wearing a mask might be useful, but experts said it was more important to wash hands. In a January 31 report, CNN said the World Health Organization recommends not wearing a mask unless you are ill or take care of a patient.
What's more, forbes posted on february 29th that: no, you do n' t need to wear masks to fight the virus, and they even increase your risk of infection.
Screenshot from Forbes website
This resistance to masks even appears in official US operations.
For example, in March, the U.S. government made it clear in the protection provided to the U.S. public that healthy people are not recommended to wear masks to protect against respiratory virus related diseases, including covid-19; on the contrary, masks are used for real people infected with new coronavirus, while medical staff and people who care for patients need masks.
Therefore, the CDC recommends that people wash their hands with soap.
However, as research into the development of the epidemic continues to deepen and asymptomatic infected people are valued, the United States CDC on April 4 issued the latest protection recommendations to the United States people wearing cloth masks to prevent the spread of the virus. At the same time, CDC also launched a tutorial on homemade masks on the website.
In fact, it's my own face.
Yet even after the CDC's recommendations were published, CDC and WHO's advice was cited in an update to the article added by the new york times on april 4 that ordinary people do not need to wear masks unless they are ill or coughing, and the new york times added that part of the reason that medical staff continue medical-grade masks.
The New York Times also stressed that masks cannot replace hand washing and social isolation.
Screenshot from New York Times website
At the same time, Forbes insisted in a follow-up update to its article that experts, including CDC, believe there is no evidence that wearing a mask can be protective.
Screenshot from CDC website
As of now, the first two of the protective advice given by CDC's official website are to wash your hands and avoid contact, and finally to cover up your mouth and nose with a cloth mask, and to make it clear that you do n' t use a medical-care-specific mask (which is why there is a shortage of medical masks).
It can be seen that even today, masks are still not paid enough attention in the United States.