Authorities in the United States are considering calling on members of the public to wear face self-made coverings in the wake of the rapid spread of the novel coronavirus (COVID-19) in the country.
A federal official who asked to remain anonymous told The Washington Post as reported on Tue (31 Mar) that officials at the Centers for Disease Control and Prevention are currently reviewing their advisory on masks.
While the official said that the CDC guidance will stress that the general public should not use medical masks — including surgical and N95 masks — to avoid further shortage of masks for frontline healthcare workers, another official said that the proposed revised recommendation may include utilising using do-it-yourself cloth coverings.
Such DIY masks may reduce the risk of transmission from the person wearing them to others around them if the person has been infected with the virus.
Thomas Inglesby, director of the Johns Hopkins Center for Health Security, however, told the Post that self-made masks made of fabric “would be a prudent step we can all take to reduce transmission”, such coverings should not be used as an excuse to stop social distancing.
Ilhem Messaoudi, a University of California at Irvine epidemiologist, told the Post via email that “it is irresponsible for anyone to suggest that we should all don masks, reducing the supply for nurses and physicians who do not have the luxury of treating symptomatic, very sick patients from 6 feet away”.
Dr Messaoudi added that COVID-19 is spread primarily through relatively heavy respiratory droplets and thus a six-foot separation between individuals coupled with frequent handwashing are still the most effective ways to stop infections.
Harold Varmus, former director of the US National Institutes of Health and the National Cancer Institute, however, said that wearing masks “also serves as a reminder to all that we are in a crisis situation and are trying to be good citizens by covering our mouths”.
Referencing a video showing anonymous researchers using laser beams in a darkened laboratory to study the way speaking can generate droplets, Dr Varmus told the Post: “The laser beam experiments demonstrate clearly that you don’t need to cough or sneeze to produce the fluid droplets that are likely to be a significant source of infectious virus: simple speech is enough to produce them.”
He also urged people to speak via virtual means instead of face-to-face during the outbreak.
The NIH, however, said that the experiment is “an early basic science experiment that while intriguing, is very preliminary”.
“The work has not been validated, peer-reviewed, or published,” NIH said.
“To suggest that this has immediate public health implications for the spread of coronavirus would be misleading,” said the institute.
Medical experts from China and S. Korea underline the importance of wearing masks during COVID-19 pandemic—contrary to WHO’s recommendation
Wearing masks in the time of the COVID-19 outbreak — contrary to the World Health Organization (WHO)’s advisory — is crucial in reducing the risk of spreading the virus, two medical experts opined.
George Gao, director-general of the Chinese Center for Disease Control and Prevention, told Science Magazine in an interview that not wearing masks — a phenomenon currently widely seen in the United States and European countries — during the COVID-19 pandemic is a “big mistake”.
“This virus is transmitted by droplets and close contact. Droplets play a very important role—you’ve got to wear a mask, because when you speak, there are always droplets coming out of your mouth.
“Many people have asymptomatic or presymptomatic infections. If they are wearing face masks, it can prevent droplets that carry the virus from escaping and infecting others,” he said.
Kim Woo-joo, a professor of infectious diseases at the Korea University Guro Hospital and South Korea’s most prominent coronavirus expert, similarly told Asian Boss in an interview on 24 Mar that wearing masks to prevent infection of COVID-19 is “definitely effective”.
“Why else would doctors wear masks in hospitals? They wear them because they prevent infection,” he added, referencing the effectiveness of masks during the SARS and MERS outbreaks.
Professor Kim, who has around 30 years of experience in the area of infectious diseases, said he finds it quite “odd” that not many people wear masks in the West.
“The US Surgeon-General said people didn’t need to wear masks, and WHO recommended people not to wear masks, but I’d have to disagree.
“I did read his tweet … You have to understand the context. I think the point was to prevent the public from hoarding masks, because medical professionals need them more,” said Professor Kim, particularly due to the shortage of masks in the US.
Professor Kim also criticised the WHO’s statement on how people are only encouraged to wear masks in Asian countries due to purported cultural differences, stating that such a view is “problematic” as masks have been “proven” to prevent infection.
“Just look at China, Hong Kong, Japan and Korea … In the meantime, if you look at many European countries and the US, the virus is spreading rapidly. One of the reasons Korea has a relatively low rate of infection is because everyone is wearing a mask and washing their hands regularly,” he said.
Professor Kim stressed that while people generally cannot catch the virus simply by breathing — the known routes of COVID-19 transmission are droplet transfer, direct contact and indirect contact with infected persons and surfaces — aerosol or airborne transmission of the virus is still possible.
Citing the Shincheonji church gathering in late Feb — which led to a supercluster in the city of Daegu and an astronomical spike in cases nationwide — Professor Kim said: “Imagine these hundreds of people gathered within one to two metres of each other, praying and singing for hours … If one infected person is present, think about the number of droplets produced.”
“We all spit even when we talk normally. but if you are singing and shouting, you are going to get a lot of droplets. Gravity doesn’t pull all the spit down, which means the droplets don’t land within one to two metres … because the air can also flow sideways,” said Professor Kim, adding that the droplets can travel “much further” than the said distance.
The droplets shrink to less than 5 microns when they dry out, turning into an aerosol that allows them to travel as far as two metres, he said.
“That’s how a person standing quite a few feet away can still get infected,” said Professor Kim.
Airborne transmission in open spaces such as parks, however, is unlikely, according to Professor Kim.
Another South Korean medical expert similarly opined that the risk of aerosol transmission in such regular outdoor environments is low.
Choi Jae-wook, professor at the Preventive Medicine Department of Korea University College of Medicine, was quoted by Korea Biomedical Review as saying that aerosols are usually only formed in specific circumstances, such as “when mucus of a patient comes out from the upper respiratory tract through coughing, or when a patient with a lot of sputum is suctioned or incubated in a hospital”.
“In some patients, upper respiratory tract infections can result in a lot of mucus, causing aerosols,” he added.
WHO’s recommendation on wearing masks only when unwell appears to have been adopted by authorities and certain medical experts in multiple countries, including in Singapore and Malaysia.
The two countries — as well as an increasing number of countries around the world — however, have amped up social distancing measures and border controls to prevent or curb the spread of COVID-19.
