Read on Twitter
1/x 
Testing = Cases
This ALSO:
(1) #False_Positive PCR results (compared to True Positives)
especially if #asymptomatics tested
&
(2) #NON_infectious cases IF excess Ct cutoff
Leads to #erroneous reporting of #NON_infectious #Cases
REF
1) https://www.bmj.com/content/370/bmj.m3699.short?rss=1&utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+bmj%2Frecent+%28Latest+from+BMJ%29
Testing = CasesThis ALSO:
(1)
#False_Positive PCR results (compared to True Positives)especially if
#asymptomatics tested&
(2) #NON_infectious cases IF excess Ct cutoff
Leads to #erroneous reporting of #NON_infectious #Cases
REF
1) https://www.bmj.com/content/370/bmj.m3699.short?rss=1&utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+bmj%2Frecent+%28Latest+from+BMJ%29
2/x REFERENCES
2) Viral cultures for COVID-19 infectivity assessment â a systematic review
By Prof @carlheneghan et al
https://www.medrxiv.org/content/10.1101/2020.08.04.20167932v3.full.pdf
2) Viral cultures for COVID-19 infectivity assessment â a systematic review
By Prof @carlheneghan et al
https://www.medrxiv.org/content/10.1101/2020.08.04.20167932v3.full.pdf
20/x REFERENCES
20) 1/x How many Covid diagnoses are #false_positives?
By @carlheneghan
Quoting,
âWhen virus levels in popân are very LOW, the chances of a test accurately detecting Covid-19 could be even <50%
for reasons #NOT widely #understood.â > https://www.google.com.au/amp/s/www.spectator.co.uk/article/how-many-covid-diagnoses-are-false-positives-/amp
20) 1/x How many Covid diagnoses are #false_positives?
By @carlheneghan
Quoting,
âWhen virus levels in popân are very LOW, the chances of a test accurately detecting Covid-19 could be even <50%
for reasons #NOT widely #understood.â > https://www.google.com.au/amp/s/www.spectator.co.uk/article/how-many-covid-diagnoses-are-false-positives-/amp
2/x conât
â. #specificity is about proportion of people who test negative, out of the popân who should have tested negative
Estimates suggest ~80% of infected people will have a positive test ( #sensitivity)..
#specificity may be as high as 99.9% for those who test negative.â>
â. #specificity is about proportion of people who test negative, out of the popân who should have tested negative
Estimates suggest ~80% of infected people will have a positive test ( #sensitivity)..
#specificity may be as high as 99.9% for those who test negative.â>
21/x REFERENCES
21) One number could help reveal how infectious a COVID-19 patient is. Should test results include it?
1/x Quoting,
â..testing centers should report .. #CT_value, which indicates HOW MUCH VIRUS an infected person harbors.â > https://www.sciencemag.org/news/2020/09/one-number-could-help-reveal-how-infectious-covid-19-patient-should-test-results
21) One number could help reveal how infectious a COVID-19 patient is. Should test results include it?
1/x Quoting,
â..testing centers should report .. #CT_value, which indicates HOW MUCH VIRUS an infected person harbors.â > https://www.sciencemag.org/news/2020/09/one-number-could-help-reveal-how-infectious-covid-19-patient-should-test-results
2/x conât
â #CT_values..who is #infectious..
#CT_value is an #imperfect #measure, advocates concede..
A test that registers a positive ..after 12 rounds, for #CT_value of 12,
starts out with >10,000,000 times as much viral genetic material
as a sample with CT value of 35â >
â #CT_values..who is #infectious..
#CT_value is an #imperfect #measure, advocates concede..
A test that registers a positive ..after 12 rounds, for #CT_value of 12,
starts out with >10,000,000 times as much viral genetic material
as a sample with CT value of 35â >
28/x REFERENCES
28) Rethinking C19 Test Sensitivity-A Strategy for Containment
1/x Quote
âKEY question is not..but #how #effectively #infections can be #detected in a population..
The #tests we #NEED are #fundamentally #different from [PCR] tests..â> https://www.nejm.org/doi/full/10.1056/NEJMp2025631
28) Rethinking C19 Test Sensitivity-A Strategy for Containment
1/x Quote
âKEY question is not..but #how #effectively #infections can be #detected in a population..
The #tests we #NEED are #fundamentally #different from [PCR] tests..â> https://www.nejm.org/doi/full/10.1056/NEJMp2025631
2/x Quote,
â..By several criteria, .. (PCR) test FAILS when used in a surveillance regimen
After collection, PCR samples ..require transport to a ..lab staffed by experts..drives up costs..delay results by 1 or more days. The cost and effort ..and slow turnaround times mean..â>
â..By several criteria, .. (PCR) test FAILS when used in a surveillance regimen
After collection, PCR samples ..require transport to a ..lab staffed by experts..drives up costs..delay results by 1 or more days. The cost and effort ..and slow turnaround times mean..â>
4/x REFERENCES
4) By @apoorva_nyc https://www.nytimes.com/2020/08/29/health/coronavirus-testing.html#click=https://t.co/xobsTYmVXI
4) By @apoorva_nyc https://www.nytimes.com/2020/08/29/health/coronavirus-testing.html#click=https://t.co/xobsTYmVXI
