Salah jika tidak memakai Masks semasa Covid
Not wearing masks to protect against coronavirus is a ‘big mistake,’ top Chinese scientist says
Not wearing masks to protect against coronavirus is a ‘big mistake,’ top Chinese scientist says
Mar. 27, 2020
Chinese
scientists at the front of that country’s outbreak of coronavirus disease 2019
(COVID-19) have not been particularly accessible to foreign media. Many have
been overwhelmed trying to understand their epidemic and combat it, and
responding to media requests, especially from journalists outside of China, has
not been a top priority.
Science has tried to interview George Gao,
director-general of the Chinese Center for Disease Control and Prevention
(CDC), for 2 months. Last week he responded.
Gao
oversees 2000 employees—one-fifth the staff size of the U.S. Centers for
Disease Control and Prevention—and he remains an active researcher himself. In
January, he was part of a team that did the first isolation and sequencing of
severe acute respiratory syndrome 2 (SARS-CoV-2), the virus that causes
COVID-19. He co-authored two widely read papers published in The New England Journal of Medicine
(NEJM) that
provided some of the first detailed epidemiology and clinical features of the
disease, and has published three more papers on COVID-19 in The Lancet.
His
team also provided important data to a joint commission between Chinese
researchers and a team of international scientists, organized by the World
Health Organization (WHO), that wrote a
landmark report after touring the country to understand the response to the
epidemic.
First
trained as a veterinarian, Gao later earned a Ph.D. in biochemistry at the
University of Oxford and did postdocs there and at Harvard University,
specializing in immunology and virology. His
research specializes in viruses that have fragile lipid membranes called
envelopes—a group that includes SARS-CoV-2—and how they enter cells and also
move between species.
Gao
answered Science’s
questions over several days via text, voicemails, and phone conversations. This
interview has been edited for brevity and clarity.
Q: What can other countries learn from the way China has
approached COVID-19?
A: Social distancing is the essential strategy
for the control of any infectious diseases, especially if they are respiratory
infections. First, we used “nonpharmaceutical strategies,” because you don’t
have any specific inhibitors or drugs and you don’t have any vaccines. Second,
you have to make sure you isolate any cases. Third, close contacts should be in
quarantine: We spend a lot of time trying to find all these close contacts, and
to make sure they are quarantined and isolated. Fourth, suspend public
gatherings. Fifth, restrict movement, which is why you have a lockdown, the cordon sanitaire in
French.
Q: The lockdown in China began on 23 January in Wuhan and
was expanded to neighboring cities in Hubei province. Other provinces in China
had less restrictive shutdowns. How was all of this coordinated, and how
important were the “supervisors” overseeing the efforts in neighborhoods?
A: You have to have understanding and
consensus. For that you need very strong leadership, at the local and national
level. You need a supervisor and coordinator working with the public very
closely. Supervisors need to know who the close contacts are, who the suspected
cases are. The supervisors in the community must be very alert. They are key.
Q: What mistakes are other countries making?
A: The big mistake in the U.S. and Europe, in my
opinion, is that people aren’t wearing masks. 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.
Q: What about other control measures? China has made
aggressive use of thermometers at the entrances to stores, buildings, and
public transportation stations, for instance.
A: Yes. Anywhere you go inside in China, there
are thermometers. You have to try to take people’s temperatures as often as you
can to make sure that whoever has a high fever stays out.
And
a really important outstanding question is how stable this virus is in the
environment. Because it’s an enveloped virus, people think it’s fragile and
particularly sensitive to surface temperature or humidity. But from both U.S.
results and Chinese studies, it looks like it’s very resistant to destruction
on some surfaces. It may be able to survive in many environments. We need to
have science-based answers here.
Q: People who tested positive in Wuhan but only had mild
disease were sent into isolation in large facilities and were not allowed to
have visits from family. Is this something other countries should consider?
A: Infected people must be isolated. That should
happen everywhere. You can only control COVID-19 if you can remove the source
of the infection. This is why we built module hospitals and transformed
stadiums into hospitals.
Q: There are many questions about the origin of the
outbreak in China. Chinese researchers have reported that the earliest case
dates back to 1 December 2019. What do you think of the report in the South China Morning Post that says data from the Chinese
government show there were cases in November 2019, with the first one on 17
November?
A: There is no solid evidence to say we already
had clusters in November. We are trying to better understand the origin.
Q: Wuhan health officials linked a large cluster of cases
to the Huanan seafood market and closed it on 1 January. The assumption was
that a virus had jumped to humans from an animal sold and possibly butchered at
the market. But in your paper in NEJM, which included a retrospective look
for cases, you reported that four of the five earliest infected people had no
links to the seafood market. Do you think the seafood market was a likely place
of origin, or is it a distraction—an amplifying factor but not the original
source?
A: That’s a very good question. You are working
like a detective. From the very beginning, everybody thought the origin was the
market. Now, I think the market could be the initial place, or it could be a
place where the virus was amplified. So that’s a scientific question. There are
two possibilities.
Q: China was also criticized for not sharing the viral
sequence immediately. The story about a new coronavirus came out in The Wall Street
Journal on 8 January; it didn’t come from Chinese government
scientists. Why not?
A: That was a very good guess from The Wall Street Journal.
WHO was informed about the sequence, and I think the time between the article
appearing and the official sharing of the sequence was maybe a few hours. I
don’t think it’s more than a day.
Q: But a public database of viral sequences later showed
that the first one was submitted by Chinese researchers on 5 January. So there
were at least 3 days that you must have known that there was a new coronavirus.
It’s not going to change the course of the epidemic now, but to be honest,
something happened about reporting the sequence publicly.
A: I don’t think so. We shared the information
with scientific colleagues promptly, but this involved public health and we had
to wait for policymakers to announce it publicly. You don’t want the public to
panic, right? And no one in any country could have predicted that the virus
would cause a pandemic. This is the first noninfluenza pandemic ever.
"Infected people must be isolated. That should happen
everywhere." _ George Gao,
Chinese Center for Disease Control and Prevention
Q: It wasn’t until 20 January that Chinese scientists
officially said there was clear evidence of human-to-human transmission. Why do
you think epidemiologists in China had so much difficulty seeing that it was
occurring?
A: Detailed epidemiological data were not
available yet. And we were facing a very crazy and concealed virus from the
very beginning. The same is true in Italy, elsewhere in Europe, and the United
States: From the very beginning scientists, everybody thought: “Well, it’s just
a virus.”
Q: Spread in China has dwindled to a crawl, and the new
confirmed cases are mainly people entering the country, correct?
A: Yes. At the moment, we don’t have any local
transmission, but the problem for China now is the imported cases. So many
infected travelers are coming into China.
Q: But what will happen when China returns to normal? Do
you think enough people have become infected so that herd immunity will keep
the virus at bay?
A: We definitely don’t have herd immunity yet.
But we are waiting for more definitive results from antibody tests that can
tell us how many people really have been infected.
Q: So what is the strategy now? Buying time to find
effective medicines?
A: Yes—our scientists are working on both
vaccines and drugs.
Q: Many scientists consider remdesivir to be the most promising drug now
being tested. When do you think clinical trials in China of the drug will have
data?
A: In April.
Q: Have Chinese scientists developed animal models that
you think are robust enough to study pathogenesis and test drugs and vaccines?
A: At the moment, we are using both monkeys and
transgenic mice that have ACE2,
the human receptor for the virus. The mouse model is widely used in China for
drug and vaccine assessment, and I think there are at least a couple papers
coming out about the monkey models soon. I can tell you that our monkey model
works.
Q: What do you think of President Donald Trump referring
to the new coronavirus as the “China virus” or the “Chinese virus”?
A: It’s definitely not good to call it the
Chinese virus. The virus belongs to the Earth. The virus is our common
enemy—not the enemy of any person or country.
.
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