U.S.COVİD – 19 cases
on the rise Questions and Answers with RAND Experts
March 18, 2020
COVID-19, the disease
caused by the new coronavirus, has now been detected in all 50 states. More
than 6,000 cases and 100 deaths have been reported so far in the United States.
With local orders to close schools, stores and restaurants going into effect in
cities around the United States, we asked several RAND researchers to answer
some questions about the crisis:
·
Jennifer Bouey,
the Tang Chair in China Policy Studies at RAND, is an epidemiologist whose
research focuses on global health strategies and the social determinants of
health.
·
Courtney
Gidengil is a senior physician policy researcher who also
practices infectious diseases at Boston Children's Hospital.
·
Laura Faherty is
a physician policy researcher and assistant professor of pediatrics at the
Boston University School of Medicine.
They spoke on a
conference call with RAND media relations director Jeffrey Hiday on
March 16. What follows is an edited transcript of the conversation, with some
updates made the following day to reflect changing information.
Are
we seeing the right approaches to the outbreak here in the U.S.? Is it
happening in good time or a little too late?
Courtney
Gidengil: Over the last 7 to 10 days,
there's been a real shift in tone and an urgency around this outbreak. We're
seeing everyone move into mitigation mode. Early on there were travel bans and
screening of travelers, all trying to prevent it from taking hold within the
United States. Now we're trying to slow the spread of the virus.
What that means is a
phrase that probably everyone has heard now countless times, which is to flatten
the curve. If you picture a bell curve, the idea is that the peak of the
curve stays as close as possible to the actual capacity of the health care
system. We may not be able to prevent the number of overall cases, but we can
spread them out over time so they don't overwhelm the health care system like
we're seeing in Italy. We're also trying to avoid health care workers getting
infected and sick because ultimately that means we can't take good care of our
patients.
Illustration by CDC
There
aren't that many serious cases yet. How are you seeing hospitals prepare?
Gidengil: Hospitals are likely to be thinking through a
lot: How to cross-train staff to work in different roles. How to get more
ventilators and where to put them if there isn't enough room in ICUs, and how
to get more personal protective equipment. How can hospitals work together in
communities? Could children's hospitals potentially treat young adults, which
was thought through in the H1N1 pandemic? How to schedule health care workers,
have clear backups, and encourage health care workers to think through their
childcare.
We have been looking
toward what's being learned in Italy, China and elsewhere. But because we're
operating within the particulars of our own health care system here in the
United States, people are looking with great interest at what is going on in
Seattle, New York City, Santa Clara and other spots where they are some days
ahead of a lot of communities in the country.
Are
there any lessons to be taken from what we're seeing in Asia or Europe?
Jennifer
Bouey: Yes. After an initial fumble in
understanding transmission, on Jan. 20, China initiated its public health
emergency and in just two days they locked down Wuhan. Soon after we saw a
steep increase of case numbers in Wuhan and its health care system was totally overwhelmed
for about two weeks. But within three to four weeks of complete shutdown, China
pretty much was able to keep the number of cases stable. And nowadays we see
that there are few new cases coming out of China. That shows that social
distancing does work if you go to a certain extreme.
We see that there are few new cases
coming out of China. That shows that social distancing does work if you go to a
certain extreme.
Jennifer
Bouey
Now China is focusing
on dealing with the large number of expats coming back, especially college
students. We have about 300,000 Chinese students in the U.S. and now many of
them are heading back to China and their families. But 80% of China's cases are
coming from within family clusters; and the government doesn't trust
self-quarantining at home. So China is struggling with how to isolate these
potential new cases coming from elsewhere.
What
are some of the social distancing measures that are being used in the U.S. and
how are they working?
Laura
Faherty: “Social distancing” is a bit of a
misnomer. We should call it “physical distancing”—while trying to maintain
social connectedness. The idea is to keep yourself as far away from other
people possible and to avoid touching surfaces that other people have touched:
doorknobs, elevator buttons, things like that.
The simplest way to
think of social distancing is, if you are able to stay home, stay home. Your
outdoor activities or exercise should be solo or with your immediate family
members who you're already exposed to. Getting basics like essential
medications, restocking food supply, etc. are obviously necessary, but we
should limit trips out to the very minimum possible. All sorts of recreational
gatherings at bars and restaurants, movie theaters and the like should be put
on hold for the time being.
We're
seeing different guidance on this. Some places are shutting down all
restaurants, some are going to take-out only, some are saying it's fine so long
as you keep everyone distant from one another.
Faherty: Yes, these guidelines are rapidly shifting and
are dependent on local context and the amount of known community transmission.
It also is dependent on an individual's health and age. A person with
underlying medical conditions or over age 60 needs to take more stringent
precautions.
The more aggressive we are at staying
home and avoiding nonessential trips outside the house, the better.
Laura
Faherty
In the United States,
we're not used to these regulations that say don't go out to a restaurant,
don't send your children to school. So I think that there's been an effort to
adjust the aggressiveness of measures to the level of risk in specific
communities at the time. I think that's adding to some of the confusion.
But the overall
message is: This will hopefully be a time-limited situation and the more
aggressive we are at staying home and avoiding nonessential trips outside the
house, the better.
How
long will we need to practice social distancing?
Faherty: That's a tough question. At least several weeks.
Potentially much longer than that. We should be mentally preparing ourselves
for this to be a marathon, not a sprint.
Bouey: Looking at the experience of China, many cities
have been on lock-down for over five or six weeks now. They're gradually trying
to bring the manufacturing sector back because of the mounting hit to their
economy. But on the other hand, the health epidemic has been well-contained so
far.
Is
it a good idea to close schools preventively?
Faherty: There are some compelling reasons to close
schools—especially in areas with suspected or confirmed community transmission.
That said, the decision is incredibly complex with significant downsides.
For instance many,
many students in disadvantaged communities rely on their school for meals,
sometimes multiple meals a day. They rely on the school as a safe place to be
if they're currently homeless. A lot of students with special needs receive
services like physical therapy and occupational therapy.
And of course there's
the question of who takes care of the children if their parents aren't able to
stay home. Will it be a grandparent who's potentially at the highest risk of
severe illness? Will a parent have to risk losing his or her job?
Some school districts are
doing a wonderful job of setting up resource centers where students can come
for meals or to be safe and taken care of. We are also seeing some innovative
strategies to maintain continuity of learning to the extent possible in these
extraordinary circumstances.
If
the period from contracting the virus to the end of contagion is, say, three
weeks, could a country that isolates itself for three weeks stamp out the
virus?
Bouey: You'd have to isolate the patients who are
infected from those who are healthy and quarantine the healthy people. So even
if there's a public lockdown with implementation of quarantine for three weeks,
we still have to think, would there be outbreaks in family clusters?
That's what we see in
Wuhan. Even though they have a city blocked off, new cases are still coming
from within families when the infected were not isolated.
So now in China they
have complete isolation. Everyone who has even a very slight chance of getting
the disease is isolated in a different setting. But even with that, once they
bring workers back to businesses, you'll still have cases with mild symptoms
that can spread the disease. This will be a long battle.
Is
it feasible to utilize hotels and motels as quarantine quarters for infected
people and that this could potentially solve two problems at once?
Bouey: China is doing that right now. Anyone entering
China from another country has to be quarantined for 14 days, even if they have
had no known contact and no symptoms. They usually have to pay for the hotel
themselves.
With students coming
back from college, some families would rather have the kids stay at a home
where they can quarantine while the family moves to a hotel during the 14-day
quarantine. The healthy family members associated with the traveler stay in a
hotel but can still go out and get food and supplies.
Initially
we heard that if you don't show symptoms, chances are you are not spreading the
disease. What do we know about that at this point?
Gidengil: This is a big question with important implications,
so I'm hoping we'll get more evidence about this. But there are two scenarios
in which a person might not have symptoms but be contagious.
The first is that
person might be recently infected and about to develop an infection; we call
such people pre-symptomatic. And I think that there is emerging agreement that
such people do have the potential to spread the infection because of this. Some
studies have measured the level of virus on day one of symptoms and find quite
high levels of virus in the nose and throat of patients. And the fact that it's
in their nose and throat—not deep in the lungs—also means it's easier to spread
potentially.
There is some evidence
from young children and babies, particularly one study of a baby who had
remarkably high levels of virus in their nose and throat, but no symptoms. And
that has an implication for the role children might play in spreading the
virus, although there is still a lot of uncertainty as to what role children
may or may not play in this outbreak.
There are a lot of
headlines in the news about asymptomatic people. Some of this has been in
non–peer-reviewed articles and more information expected to come out. But in
speaking to infectious disease doctors, most say that for the majority of this
to spread by totally asymptomatic people would make it quite unlike other
diseases that we've ever seen. And the guidance we had been getting from CDC is
that asymptomatic people are not likely to be driving this pandemic. That being
said, there is still a lot to be learned and these assumptions could change
over time; it's possible that people with quite mild symptoms may be driving
most of the spread of the infection.
But it's important to
know for sure whether asymptomatic people can be contagious. Containing the
virus with methods such as screening for symptoms would be exceedingly
difficult or almost impossible if we can't tell people to quarantine themselves
or to get tested based on symptoms.
Is
it true that for most people who will be sick with COVID-19, the symptoms would
show up by the fifth day after exposure?
Gidengil: The range is 2 to 14 days. Many (about half) do
show up by day 5, and the vast majority by 10 days. Very few show up between
days 10 and 14 and a tiny tail after that. We're still sticking to 14 days as
the length of quarantine, because that's reasonably the latest we think you can
develop symptoms.
Does
the virus eventually need to make its way through a community to confer
immunity and spend out the virus?
Gidengil: There have been concerns that the UK may be
adopting this approach. How safe it is to allow that to happen depends on the
burden on the health care system.
It's also important to
think about immunity and how much of a hold we want to allow the virus to have.
Certainly, this infection could become more endemic; rather than outbreaks, it
may become something that just always exists in particular communities. There's
also a question of how long-lasting immunity is.
Does
the virus spread faster in cold climates? And if so what does that mean for the
curve flattening in the summer in the U.S.?
Bouey: There are some hypotheses like that based on
SARS, which appeared around the same time in November and December, and when
the World Health Organization identified the virus and epidemic, it was already
in April. When China implemented quarantines, it was May–June and the new cases
soon disappeared.
Based on that example,
lots of people think, OK, this is another coronavirus, and in addition to the
quarantine measures implemented, maybe the warm weather also helped. That's the
hypothesis.
But so far we have
seen cases of community transmission in Singapore, in Guangzhou, and many
warm-weather places. So it's a hypothesis that no one has confirmed yet.
If
over the last few months people who'd had flu shots got something severe and
flu-like, any chance they had coronavirus and, if so, what would the
implications for that be?
Gidengil: It's hard to know. There has been a fair number
of severe respiratory viruses this season. It has been a very, very difficult
flu season. But I don't think anyone can say with certainty whether those
people had COVID-19 rather than the flu because we haven't had the ability to
test those people for coronavirus.
Hopefully we'll soon
have antibody testing as well and that'll give us a much better handle on
whether someone was exposed to COVID-19 or had it. I doubt that we'll be able
to test everybody, but we'll be able to do some population studies that will be
very helpful.
Have
scientists figured out whether a person who has recovered from COVID-19 has
immunity, or can they get it again?
Gidengil: I don't think we have a handle on that yet. With
SARS, we saw at least some immunity, but it's also clear that SARS behaves
differently. With the new coronavirus, there have been news reports of
individual people testing negative and then they redeveloped symptoms and
tested positive. It's not clear why this is happening—whether their throat
wasn't swabbed well enough or some other reason the test didn't go well, or
whether they are getting the infection again.
As I was saying, we
need antibody or titer testing to understand some of these cases. That would
help us know not only who was infected, even if they didn't know it, and speak
to some of this asymptomatic question. It would also help us understand what
level of antibody you need to have immunity.
It would be unusual
for people to not have any immunity whatsoever to this virus. That would be
unlike most viruses we've observed. Then again, as I said, this virus is new
and may behave differently.
Where
do we stand with the amount of testing being done in the country?
Gidengil: We still don't have enough tests to go around
for everyone who is presenting sick to emergency rooms. There have been more
tests available in recent days, and my sense is that hospitalized patients can
now be more relatively easily tested.
In addition to testing
in the state labs and at the CDC we also have some commercial labs that over
the last week have started to take tests. I don't know how much backlog they
may eventually acquire or what volume of testing they're getting. I think we
can expect the testing will increase, although I think there's still
uncertainty as to whether it can truly meet capacity or not.
We still don't have enough tests to go
around for everyone who is presenting sick to emergency rooms.
Courtney
Gidengil
The other big issue is
who is going to actually do the testing. Primary care providers don't have
enough personal protective equipment to test someone. If you're testing someone
and they're coughing and sneezing in your face, you're supposed to wear
particular types of personal protective equipment and they just don't stock
that in the primary care offices. Or they don't have the swabs to do the test.
We are seeing some
pretty innovative approaches: drive throughs and tents outside of hospitals.
There are many aspects to ramping up the testing besides just the test kits.
And
what about the supply chain? Do we have enough reagents, for example?
Bouey: The three or four weeks of shutdown after
Chinese New Year in China caused lots of anxiety globally about supply chain.
China produces about half of the global production of chemicals, metals,
electronics and textiles.
API, the active
pharmaceutical ingredients, has become a big concern in the U.S. and other
countries. China provides about 80% of the API for both generic and other
medicines. What I've heard is that most of the generic drug makers in India are
using China's API, but because of the Chinese New Year and seasonal storage,
they usually have three months of stock. If China's manufacturing sector
doesn't come back to normal production until April, that will be become more of
a problem.
China is also a big
producer of face masks and all of that personal protection gear. Hopefully,
production there is much enhanced because they put a priority on those medical
supplies and soon they will be willing to start exporting again.
Can
you talk about surveillance testing, and why that would be helpful if we had
sufficient tests available?
Gidengil: About three or four weeks ago, the CDC had
announced that they were going to do surveillance in five major cities
including New York City, Los Angeles, San Francisco, Chicago and Seattle. I
thought that was proactive. They were going to use the existing flu
surveillance network—outpatient practices that send flu swabs from a certain
proportion of all patients who have compatible symptoms.
The hope would have
been to detect some early signal ahead of seeing people present very sick,
because there was a delay between when you get infected to when you're so sick
that you maybe need to be in the hospital.
Unfortunately, to my
knowledge, that has not come to fruition. The presumed reason is CDC's test
kits were not working as expected and there was an inadequate supply. But once
we get enough, that will be incredibly important to do. It could let
communities know what to expect, or if the number of cases detected indicates
there's a surge coming. Surveillance is a cornerstone of public health and we
can't know what's happening without taking some action.
What
are the main differences in the underlying assumptions used in the models that
suggest contradictory approaches to handling the crisis, such as in the U.S.
and UK?
Bouey: One of the things we talk about when we assess
interventions is political feasibility and viability. We have to think about
the cultural and social environment. Those are all part of the reason that
different policies can come out in different countries.
However, I still feel
that any policy implementation should be based on evidence and science in terms
of whether we want to have the immunity passive or active. Passive immunity
means that you just let people get the disease and then produce a herd
immunity. Whereas active immunity means that we have a vaccine and we protect
large populations that way. Before the vaccine is available, the only public
health tool is social distancing.
So we want to make
sure that we understand the disease transmission and the capacity of our health
care system, as well as the population's willingness to get tested and do the
social distancing. All those things should be understood and factored into
these policies.
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