Coronavirus Epidemic Update 22: Spread Without Symptoms, Cruise Quarantine, Asymptomatic Testing


welcome to another MedCram lecture and
we can see here the numbers are increasing but slowly here on the world
ometer website seventy five thousand seven hundred and thirty total deaths
2128 recovered sixteen thousand if we look at the active cases in the close
cases you can see that the number of recovered has gone up slightly and seems
to be doing that on a daily basis if we look at the total worldwide cases you
can see here that they are dwindling overall but in looking at the cases that
are outside of china we can see that they continue to increase in terms of
the number of deaths unfortunately those continue to be increasing pretty much at
a linear rate want to update you on the situation with the Diamond Princess
cruise ship that’s docked outside of Japan there was a statement put out by
the CDC commending the Government of Japan for the fact that they quarantine
patients but there’s been a lot of international criticism of how Japan
actually handled this and there’s been an intervention and basically the
consensus if you read between the lines is that this did not work very well
there’s currently more than a hundred US citizens either on board the diamond
princess or in hospitals in Japan and they’ve been placed under the
restrictions and they’re saying that they will be required to wait 14 days
before coming home before they’re permitted to come on board flights
however if an individual does make it to the United States before that 14-day
period ends they will be subject to a mandatory quarantine until they
completed that 14-day period so the CDC is coming out with that statement and
they want to make sure that everyone’s aware that they are taking this
seriously I also want to quickly highlight a letter that was submitted to
the New England Journal of Medicine dated yesterday February 19 it was an
interesting look at about 18 patients nine men and nine women meeting 59 years
of age and what they did was they looked at viral loads in the upper respiratory
tract to see what they were based on when the symptoms began
and now these were people from Wuhan and all of them except for one were
symptomatic there was one person that was asymptomatic and we’ll talk about
that in just a second but you can see here the graphs of the
CT value which is basically the viral load and on the x-axis here is the
number of days since the onset of symptoms zero being here on the far left
and what you can basically see is that the viral load was quite high in the
very early days of the symptoms and then tapers off almost all of them being
undetectable here towards 14 days now please don’t confuse these days as the
incubation period this has nothing to do with the incubation period this has to
do with how long the symptoms last once you get the symptoms an incubation
period has to do with how long it is between infection and the onset of
symptoms the other thing to notice here at the bottom is may be difficult to see
but in terms of throat swabs versus nasal swabs there was a higher viral
count in the nasal swabs in general than there was in the throat swabs meaning
that this virus tends to potentially congregate in the upper Airways there
was one patient that was tested and was asymptomatic and they say here that the
viral load that was detected in the asymptomatic patient was similar to that
in the symptomatic patients which suggests that the transmission potential
of asymptomatic or minimally cyntha matic patients and this is confirming
what we had discussed earlier at the beginning of this outbreak that
potentially can be spread by asymptomatic individuals and we will put
a link in the description below to this article as well as the CDC article
another article that was submitted on the same day yesterday was a perspective
that was written by a number of physicians and epidemiologists on their
perspective of defining the epidemiology of kovat 19 and how more studies are
needed one of the interesting aspects that they mention here is they may need
to do testing in people that may not meet the current definitions which is
someone who has traveled from that particular area of China and has
symptoms and they say here a key point of these recommendations is that viral
testing should not be used only for clinical
CAIR I think that’s an interesting point if we really want to find out what the
scope is of the infection especially in China that there’s gonna have to be a
lot of people who are asymptomatic Lee tested to see whether or not they had
the virus at some point anyway I leave that perspective there for your
consideration in future updates we’ll plan on tackling the molecular biology
of corona virus and contrast that and compared to other viruses and that might
give us a little bit of information about what this virus likes to do please
join us at make cram comm for our course on the corona virus also multiple other
courses thanks for joining us

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