welcome to another MedCram update let's talk about California and testing but
before we do let's just review total confirm eighty 2164 total deaths 2800 oh
one total recovered thirty two thousand eight hundred and ninety seven we see
more of a continuation of what we've been seeing in the past let's go to the
world ometer we gonna talk a little bit about testing today and also the
positivity rate and UK they have well over seven thousand tests of which only
thirteen are positive and that's a very low positivity rate of course in Italy
where they actually have an outbreak they've done over nine thousand tests of
which only four hundred and seventy are positive it's about a five percent
positivity rate in France two point two positivity rate in Austria 321 tests of
which two are positive and then in the United States notice we've only done
four hundred and forty five concluded tests of which fourteen are positive and
that's around three point one positivity rate these tests are not as sensitive as
you may think that you're going to be surprised that the sensitivity on these
tests are only around seventy percent and so it is possible to have a negative
test and to still be infected with the corona virus we see that there are so
far 334 new cases and one death in South Korea and the number of confirmed cases
expected to jump in the coming days as health authorities have started testing
more than two hundred and ten thousand members of this church and Daegu if we
look at the numbers coming out of China and the rest of the world in terms of
the total deaths that seems to be leveling off and if we look at the
number of daily new cases outside of China that has hit its highest amounts
ever on February 26 with daily cases of 569 I want to go to a local site
Eyewitness News here in Southern California a new case
that has been detected in Northern California in a resident who has not
traveled overseas couple things that I want you to be
aware of this patient is a resident of Solano County turns out that Solano
County is the home to Travis Air Force Base where Americans returning from
overseas were quarantined the patient was transferred back on February 19th so
that was about a week ago from undisclosed hospital to UC Davis health
and that is the hospital in Sacramento for the University of California Davis
patient had already been intubated was on a ventilator and was given droplet
precautions orders because of an undiagnosed and suspected viral
condition so there are other viruses that can do this now at the time it
seems as though UC Davis had asked the CDC for testing but this was not done at
the time and if you go to the CDC website it tells you what their
requirements are for testing although they do put a disclaimer that they will
look at a case-by-case basis but essentially unless you traveled to Wuhan
or that part of China they weren't really going to be doing that kind of
testing so it's unclear how eventually UC Davis was able to get CDC to test
this patient but they did and eventually on Sunday the CDC ordered the Cova 19
testing of the patient at that time the patient was put into airborne
precautions what does this mean it means that anybody going into that room had to
have an n95 mask and had to go into contact isolation precautions that means
they would have to wear a gown gloves they may even have to wear I wear
protection if they were not able to do that then they would have to go under
something called poppers where they basically go in with a mask that was
vented from Sunday to Wednesday it took for the CDC to confirm finally that the
patient's test was positive the small number of employees were to go home and
monitor their temperature for any kind of fever or things of that nature
and the key here is to recognize apparently this patient had no travel to
that part of the world they go on to say here at this time the patient's exposure
is unknown it's possible that this could be an instance of
they call community spread of kovat 19 which would be the first time that this
has happened in United States it's also possible however they said
that the patient may have been exposed to a returned traveler who was infected
of course this brings up the issue of anybody that comes when with fever or
signs and symptoms of a viral illness and shortness of breath could be
potentially a carrier of this novel coronavirus and that's why it's really
important to have lots of personal protective equipment at hospitals where
they belong instead of running out at hospital so it's really important that
hospitals have the ability to acquire personal protective equipment because
you don't want to show up to a hospital where the employees there or the doctors
or the nurses don't have the adequate amount of protection so that they don't
pass the virus on to anybody else that might show up at that hospital so please
do not take masks and protective equipment from hospitals for your own
use but this really brings up a big issue and that is how do you test people
for coronavirus how do you know quickly whether or not this person that's coming
in has this virus obviously if we see here in this case it took them from
Wednesday when they actually got the causative test all the way from Sunday
when they first order the tests you can see that that's not the optimal
situation especially when we add to the situation that this test is not really
that sensitive meaning that if you have a negative test you can absolutely rule
it out so enter a study that I think is going to be important and that is this
science Daily News article which talks about this article that was just
published in radiology called CT provides the best diagnosis for kovat
19:00 I will put a link to it in the description below basically what they
did is in China they looked at over a thousand patients and they did this
reverse transcriptase polymerase chain reaction which is what rt-pcr stands for
this is where you look for the actual RNA of the patients and compared it to
the classical findings that they see on CT scan here's another news item of the
same article so title as CT provides best diagnosis for kovat 19 and it says
the study from China shows that chest CT demonstrates better sensitivity than
this blood test looking for the actual pcr of the virus
remember that halfway through the epidemic last month they changed the
criteria in the definition for the diagnosis of kovat 19 so you can see
here in a study of more than a thousand patients that was published in the
journal article radiology which we link to so you can look at it for yourself
chest CT actually outperformed lab testing in the diagnosis of 2019 novel
coronavirus and this was looked at in Wuhan China so it's important to
understand that you have to make an early diagnosis of kovat 19 if you're
going to isolate and you're going to prevent the spread of that disease as we
talked about earlier in a early jam article 41 percent of patients who
contracted Co vyd 19 did so in the hospital and the majority of those 41
percent were healthcare workers according to the latest guidelines by
the Chinese government the diagnosis must be confirmed by reverse
transcriptase polymerase chain reaction or the gene sequencing they say here
however that those throat samples are only about 30 to 60 percent positive at
initial presentation having a low sensitivity implies that there's going
to be a lot of people who will be negative initially and you're gonna miss
those people those people are going to come through into your hospital and
potentially infect other people specifically people who are there to
help and causing them to be taken out of work and put into isolation most likely
and so they say here that early diagnosis of copán 19 is crucial for the
disease treatment and control compared to rt-pcr that is the genetic testing
they say here that chest CT imaging may be a more reliable practical and rapid
method to diagnose and assess kovat 19 especially in the epidemic area so why
did they think that well let's take a look and see this
there was over a thousand patients who underwent both CT chest and rt-pcr tests
from January 6 to February 6 and what they did was they looked at all of those
people who had a positive PCR and there was about six hundred and one of those
and everybody that had a positive CT scan and there was eight hundred and
eighty eight of those and then they asked the question well what's the
sensitivity what's the specificity and what's the accuracy and what they found
was that about eighty one percent of patients with a negative rt-pcr
but a positive CT scan were reclassified as highly likely or probable cases with
kovat 19 based on the comprehensive analysis of clinical symptoms typical CT
manifestations and dynamic CT follow-ups what they mean by that they were getting
worse and they were consistent they also found in a lot of these that the initial
tests may have been negative but that follow-up tests turned positive
confirming in a lot of these cases the original CT findings let's review those
results the results showed that 59 percent of these patients that they
tested had PCR results that were positive eighty eight percent had
positive CT scans they said that the sensitivity and this is something that
you want to be very very high in this situation because something that is very
sensitive means that if it is negative you can practically rule it out and as
it turned out that sensitivity of chest CT was 97% based on positive rt-pcr
results in patients with negative rt-pcr results seventy-five percent of those
patients had positive CT findings and of those forty eight percent were highly
likely cases so what we're seeing here is that CT scans may be the way to get a
quick screening of whether or not your patient with fever is likely to have
kovat 19:00 but the question is what are the findings on CT it's good enough to
know that you should get a CT but what is it that you should be looking for I'm
going to link in the description below a youtube video describes the findings
on CT scan of known cases of copán night and that concludes our update for today
realize that many of these videos are made the evening before they get
released because I still am working in the intensive care unit seeing patients
every single day and so this is something that I do at the end of the
day because we as healthcare providers are on the front line and we have to be
prepared thanks for joining us