6 ms·

How should this be interpreted? Isn’t implying that the test can’t tell the difference between flu and covid? If that’s true, then, how can we be sure that flu

How should this be interpreted? Isn’t implying that the test can’t tell the difference between flu and covid? If that’s true, then, how can we be sure that flu hasn’t been misdiagnosed? What percentage of Covid cases were classified using PCR tests?

unanswered 5y ago
> If that’s true, then, how can we be sure that flu hasn’t been misdiagnosed? Because I haven't seen anything on Facebook, or self-censoring HN for that matter, validating those claims. So they must be but only false but really out-there wacky conspiracy theories.
13years 5y ago
Yes, it does state that. However, there is the word 'and' between detection and differentiation. The original could not detect, so therefore differentiation is a moot point. Also, the test for flu was a separate test. So it would have had no effect on the lower flu incidence assuming we didn't test for flu at a lesser rate.
- _-david-_ 5y ago
  >assuming we didn't test for flu at a lesser rate. Do we have any numbers on this? I would imagine a lot of people who went to the doctor or whoever complaining of flu like symptoms would have been tested for covid.
  - jtbayly 5y ago
    Yes. We have figures for it. In 2017-18, there were 1.21M flu tests over the course of 33 weeks. In 2020-21 there were 1.11M flu tests over 33 weeks. Results: Essentially a 0% positive test rate vs a peak of over 25%. A peak of about 125 cases vs 20,000 cases. 1: https://stacks.cdc.gov/view/cdc/54973 https://stacks.cdc.gov/view/cdc/54973 2: https://www.cdc.gov/flu/weekly/weeklyarchives2020-2021/data/whoAllregt_cl28.html https://www.cdc.gov/flu/weekly/weeklyarchives2020-2021/data/...
    - _-david-_ 5y ago
      Any chance you know about 18-19 and 19-20 as well?
      - mcbits 5y ago
        They've archived past weekly reports going back to 1999-2000 (not sure if that's when the weekly report started or just when the archive starts), although the formatting and specific information has changed over the years. https://www.cdc.gov/flu/weekly/pastreports.htm https://www.cdc.gov/flu/weekly/pastreports.htm
torstenvl 5y ago
It does not imply that. It would be effectively impossible for that to happen. PCR testing is a crude form of genetic test. Influenza viruses and coronaviruses are not closely related. It's more likely that a genetic test would confuse influenza for ebola (another negative sense single strand RNA virus) than for a coronavirus infection.
dathinab 5y ago
This groups of people do not just imply that > Isn’t implying that the test can’t tell the difference between flu and covid? they are strongly convinced that this is the case, quoting papers or research showing that in some rare cases with some methods you could have tests which could sometimes confuse Covid with other Corona Viruses (not flu, completely ignoring that this might not apply to the tests they are speaking about or that the probabilities are negligible.) I had to realize that the majority of people (which haven't studied something where they had to learn it) do not understand stochastic at all, but believe they have some basic understanding of probabilities (which they don't have). Furthermore it's not uncommon for people to reject truth which do not fit into their world view. Not to long ago I realized that a relative of mine does not understand the difference between false positives and false negatives and that they are not equally likely. They knew the (fast, non PCR) test can be wrong and as such believed it can be equally wrong in all directions including false positives. So because it was confirmed that the test have many false negative they believed that they also must have many false positives and as such the increase in cases must be because of this false positives... I tried to reach out to them and explain them that false positives and false negatives are not the same and just because something can likely fail in one way it doesn't mean it will also fail likely in another way. But I completely failed to reach them, they insisted on their opinion being correct and went very fast into a defensive mode where it's impossible to reach them no matter what how reasonable and convincing your arguments are.

unanswered 5y ago

> If that’s true, then, how can we be sure that flu hasn’t been misdiagnosed? Because I haven't seen anything on Facebook, or self-censoring HN for that matter, validating those claims. So they must be but only false but really out-there wacky conspiracy theories.

13years 5y ago

Yes, it does state that. However, there is the word 'and' between detection and differentiation. The original could not detect, so therefore differentiation is a moot point. Also, the test for flu was a separate test. So it would have had no effect on the lower flu incidence assuming we didn't test for flu at a lesser rate.

_-david-_ 5y ago
>assuming we didn't test for flu at a lesser rate. Do we have any numbers on this? I would imagine a lot of people who went to the doctor or whoever complaining of flu like symptoms would have been tested for covid.
- jtbayly 5y ago
  Yes. We have figures for it. In 2017-18, there were 1.21M flu tests over the course of 33 weeks. In 2020-21 there were 1.11M flu tests over 33 weeks. Results: Essentially a 0% positive test rate vs a peak of over 25%. A peak of about 125 cases vs 20,000 cases. 1: https://stacks.cdc.gov/view/cdc/54973 https://stacks.cdc.gov/view/cdc/54973 2: https://www.cdc.gov/flu/weekly/weeklyarchives2020-2021/data/whoAllregt_cl28.html https://www.cdc.gov/flu/weekly/weeklyarchives2020-2021/data/...
  - _-david-_ 5y ago
    Any chance you know about 18-19 and 19-20 as well?
    - mcbits 5y ago
      They've archived past weekly reports going back to 1999-2000 (not sure if that's when the weekly report started or just when the archive starts), although the formatting and specific information has changed over the years. https://www.cdc.gov/flu/weekly/pastreports.htm https://www.cdc.gov/flu/weekly/pastreports.htm

torstenvl 5y ago

It does not imply that. It would be effectively impossible for that to happen. PCR testing is a crude form of genetic test. Influenza viruses and coronaviruses are not closely related. It's more likely that a genetic test would confuse influenza for ebola (another negative sense single strand RNA virus) than for a coronavirus infection.

dathinab 5y ago

This groups of people do not just imply that > Isn’t implying that the test can’t tell the difference between flu and covid? they are strongly convinced that this is the case, quoting papers or research showing that in some rare cases with some methods you could have tests which could sometimes confuse Covid with other Corona Viruses (not flu, completely ignoring that this might not apply to the tests they are speaking about or that the probabilities are negligible.) I had to realize that the majority of people (which haven't studied something where they had to learn it) do not understand stochastic at all, but believe they have some basic understanding of probabilities (which they don't have). Furthermore it's not uncommon for people to reject truth which do not fit into their world view. Not to long ago I realized that a relative of mine does not understand the difference between false positives and false negatives and that they are not equally likely. They knew the (fast, non PCR) test can be wrong and as such believed it can be equally wrong in all directions including false positives. So because it was confirmed that the test have many false negative they believed that they also must have many false positives and as such the increase in cases must be because of this false positives... I tried to reach out to them and explain them that false positives and false negatives are not the same and just because something can likely fail in one way it doesn't mean it will also fail likely in another way. But I completely failed to reach them, they insisted on their opinion being correct and went very fast into a defensive mode where it's impossible to reach them no matter what how reasonable and convincing your arguments are.