
Coronavirus relapse cases continue to rise in S. Korea - jdc
https://en.yna.co.kr/view/AEN20200417006800320
======
mrandish
Scientists agree reinfection is an unlikely explanation for patients who test
positive a second time, according to the Los Angeles Times, and note the
possibility that testing errors, and releasing patients from hospitals too
prematurely, are more likely the reason for reports of patients who retest
positive.

“If you get an infection, your immune system is revved up against that virus,”
Keiji Fukuda, director of Hong Kong University’s School of Public Health, told
the Los Angeles Times. “To get reinfected again when you’re in that situation
would be quite unusual unless your immune system was not functioning right.”
Fukuda told the paper that it’s more likely patients are being released from
hospitals while carrying dormant fragments of the disease that are not
infectious, but resemble the virus when tested. “The test may be positive, but
the infection is not there,” he said.

[https://thehill.com/changing-america/well-
being/prevention-c...](https://thehill.com/changing-america/well-
being/prevention-cures/487436-can-you-get-coronavirus-twice)

The OP article says

> "No secondary infections have been reported from relapse cases, according to
> the KCDC."

~~~
DataWorker
Korean doctors are able to speak for themselves and we should rely on the
studies themselves to inform discussion, not hearsay from a third party source
about “scientists agree” whatever the heck that means. What do the Korean
doctors who are reporting the alleged reinfection think.

~~~
danielfoster
It’s most likely dead virus causing a false positive:
[https://www.cnn.com/2020/04/17/health/south-korea-
coronaviru...](https://www.cnn.com/2020/04/17/health/south-korea-coronavirus-
retesting-positive-intl-hnk/index.html)

------
mixmastamyk
My own experience, the virus lingers after you beat it, waiting to return.

For example, if I have a few drinks or don’t get enough vitamins it starts to
come back mildly until I reverse course.

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yanks215
Is it possible that this remains dormant, somehow, similar to herpes viruses?
Where could the virus hide? I am not a physician or scientist, but this
article indicates that an S protein, like that which is present in covid-19,
can bind to ace2 receptors -- so would it be unreasonable to think that it
could hide, dormant, in this receptor?

[https://www.cell.com/trends/pharmacological-
sciences/referen...](https://www.cell.com/trends/pharmacological-
sciences/references/S0165-6147\(04\)00097-5)

~~~
vikramkr
Viruses cant hide inside of receptors or the like. When a virus goes latent
(the term you are looking for is viral latency), the genetic material of the
virus finds a way to hide out inside a cell. The genetic material either
floats around inside a protected area of the cell (episomal, think herpes) or
actually integrates and becomes a part of your own dna (proviral, think HIV).

I don't know of any conclusive evidence yet that any coronavirus establish an
HIV/herpes style latent infection. Of it turns out they do, then, to put it
mildly, that is a very very very very big deal and a very very bad problem to
have.

[https://en.wikipedia.org/wiki/Virus_latency](https://en.wikipedia.org/wiki/Virus_latency)

------
henryw
"The KCDC said it took 13.5 days on average for people to be retested positive
for COVID-19 after being released from quarantine."

Maybe they were never fully recovered.

~~~
BearOso
I’m thinking some people pulled strings to get discharged early. South Korea
is sequestering people in hospitals if they’re positive, and that’s not
exactly a fun experience.

------
jdc
To be clear, things are still looking good for South Korea in general[1], but
it's good to know that relapse is possible.

1\.
[https://m-en.yna.co.kr/view/AEN20200418001051325](https://m-en.yna.co.kr/view/AEN20200418001051325)

------
Waterluvian
Are humans typically immune to any and all viral infections that their immune
system fights off? Like its just kind of a rule? Either you die or you become
immune?

~~~
klipt
I don't have a link, but I remember reading elsewhere that with other
coronaviruses (many cold viruses are in this category), it's thought possible
to be reinfected after a while, _especially if the symptoms are mild_. The
worse the symptoms, the stronger and longer lasting the immune response tends
to be, which reduces chance of reinfection.

Edit: this may be relevant
[https://www.npr.org/sections/goatsandsoda/2020/03/20/8190384...](https://www.npr.org/sections/goatsandsoda/2020/03/20/819038431/do-
you-get-immunity-after-recovering-from-a-case-of-coronavirus)

> Researchers do know that reinfection is an issue with the four seasonal
> coronaviruses that cause about 10 to 30% of common colds. These
> coronaviruses seem to be able to sicken people again and again, even though
> people have been exposed to them since childhood.

~~~
gentleman11
I read as a teenager this was always due to mutation. Do these viruses not
change over time?

------
imajoo
(I am not a scientist) I remember seeing someone talk about the risk of re-
infection when this all started. They said that they only way to fully know if
the virus has mutated would be to do a full sequence of the virus comparing
the first infection with the second. It will be interesting (and possibly
scary if has mutated) to see what is causing this second re-infection of
patients that are supposedly recovered.

Here's an article talking about people getting re-infected at the end of Feb.
[https://www.livescience.com/coronavirus-spread-after-
recover...](https://www.livescience.com/coronavirus-spread-after-
recovery.html)

~~~
brianpan
Covid-19 mutates about 2x a month. [https://bedford.io/blog/ncov-cryptic-
transmission/](https://bedford.io/blog/ncov-cryptic-transmission/)

This doesn't mean the virus has changed enough for your body to not recognize
it. But it can be used to map transmission chains.

We know where Covid-19 started, but scientists have also used mutation rates
to correct our understanding of when HIV jumped to humans.

~~~
officialjunk
We know where it was first identified as a new virus, not where it started.

There are numerous reports of Italy’s search for patient zero pointing to it
being there before China.

“ Remuzzi says he is now hearing information about it from general
practitioners. "They remember having seen very strange pneumonia, very severe,
particularly in old people in December and even November," he says. "This
means that the virus was circulating, at least in [the northern region of]
Lombardy and before we were aware of this outbreak occurring in China."”

[https://www.npr.org/2020/03/19/817974987/every-single-
indivi...](https://www.npr.org/2020/03/19/817974987/every-single-individual-
must-stay-home-italy-s-coronavirus-deaths-pass-china-s)

------
mikhailt
It's not clear but does this mean they're still contagious regardless of
symptoms (since many are asymptomatic)?

> "Of the 137 cases that have clinical and epidemiological information, 61
> showed symptoms again, the KCDC said."

