/cvg/ KCDC report: Findings from Investigation and Analysis

KCDC report: Findings from Investigation and Analysis of Re-Positive Cases
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SUMMARY / QRD
-------------

  - RELAPSE CONFIRMED
  - ~45% of repositives have symptoms again
  - seem unable to infect others so far
  - no viable viral load in upper resp sys
  - virus most probably hiding in lower resp sys
  - some relapsed cases can't be detected by nasal swab
  - testing must use induced sputum / BAL fluid (US CDC not recommending these)




report published: 2020-05-19

link: http://is.cdc.go.kr/upload_comm/refile.do?cmd=fileDownloadC&comfile_se=6p1fD68SkG8Ji232Luk6EzmoMf06oH22eTF6IHxQOqk=&comfile_fs=20200519225429087696709&comfile_fn=Findings+from+Investigation+and+analysis+of+re-positive+cases_final.pdf&comfile_c=www1&comfile_fd=1589911679411

> Epidemiological investigation and contact investigation have been completed for 285 (63.8%) of the
total 447 re-positive cases (as of 15 May).

> 59.6% were tested as a screening measure, and 37.5% were tested because of symptom onset. Of the
284 cases for which symptoms were investigated, 126 (44.7%) were symptomatic.

> From the 285 re-positive cases, a total of 790 contacts were identified (351=family; 439=others). From
the monitoring of contacts, as of now, no case has been found that was newly confirmed from
exposure during re-positive period alone.

resurgence of symptoms
----------------------

  44.7% experienced symptoms ("such as coughs, sore throat, etc.") again


viral load & infectiousness
---------------------------

  viral cell culture testing of 108 re-postive cases => negative
  so the "virus" found in the RT-PCR tests is just dead RNA, not viable viral load
  so these people can't (so far) infect others

  report also says that there is no infection purely due to contact with a re-positive person:
  > From monitoring of 790 contacts of the 285 re-positive cases, no case was found that was
  > newly infected solely from contact with re-positive cases during re-positive period.


how come symptoms and no viral load?
------------------------------------

  possible theories:

    - virus is in lower respiratory system, won't show up in nasal swab tests [CONFIRMED, see "matching case in New York"]
    - virus is in central nervous system (CNS), causing respiratory symptoms
    - autoimmune response?
    - virus presence somehow strong enough to cause some symptoms yet weak enough to show up as viral load?


antibodes
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  > Of the 23 re-positive cases from which the first and the second serum samples were obtained,
  > 96% were positive for neutralizing antibodies.

  antibodies don't protect you from relapse?


other viruses/diseases?
----------------------

  93 re-positive cases were tested for 8 other respiratory viruses:

  > Influenza, parainfluenza, rhinovirus, metapneumovirus, human coronavirus,
  > adenovirus, bocavirus, respiratory syncytial virus

  3 positive for other viruses (2 adenovirus, 1 bocavirus)
  90 negative (i.e. they had only corona)


re-positive cases age breakdown (kids, adults, elderly)
-------------------------------------------------------

  percentage people re-positive after discharge:

  in Sejong City (n = 27):
    overall = 25.9%

  in Daegu City schools (n = 195):
    overall = 27.2%
    school staff (adults) = 12.8%
    students (kids) = 31.8%

  in Gyeongbuk Province's Pureun Nursing Home (n = 47):
    overall (elderly) = 48.9%



matching case in New York
-------------------------

  http://archive.is/LF4oe

  - 34 y/o male in otherwise good health
  - initally positive for influenze A, symptoms gone after routine treatment

  - 10 days later, he returned to work, fell very ill on the same day and admitted
  - symptoms: fever, chills, shortness of breath, CYTOKINE STORM
  - nasal swab negative for COVID-19
  - symptoms improved after antibiotics

  - 5 days later, condition worsens
  - lung scan shows "halo-like sign of inflammation in the right lung, which radiologists suggested could be a fungal infection"

  - lung fluids extracted using BAL (bronchoalveolar lavage)
  - they tested positive for COVID-19

  > The doctors were also puzzled by the absence of virus in the upper respiratory samples
  > even at the peak of infection, adding that this could be the result of a previous medication.
  > The patient had been taking drugs on a regular basis for pre-exposure prevention of HIV,
  > an occupational hazard for doctors in New York.

  matches KCDC's relapse findings (no viral load in upper resp sys)

  it's all but confirmed that the virus hides in lower resp sys

  thanks to svenanon


testing
-------

  some cases (see "matching case in New York") can't be detected by nasal swab

  SARS-CoV-2 RNA more readily detected in induced sputum than in throat swabs of convalescent COVID-19 patients:
    https://www.thelancet.com/journals/laninf/article/PIIS1473-3099(20)30174-2/fulltext
    https://archive.is/3xrPN

  CDCs still refuse to endorse them despite evidence



see also: "The Virus" by fatanon (https://www.youtube.com/watch?v=SROaLrEY-NQ)