3 ms·

> A negative test can tell us: > the person was unlikely to be infectious at the time of the test. https://www.health.govt.nz/our-work/diseases-and-conditions

> A negative test can tell us: > the person was unlikely to be infectious at the time of the test. https://www.health.govt.nz/our-work/diseases-and-conditions/covid-19-novel-coronavirus/covid-19-health-advice-general-public/assessment-and-testing-covid-19/covid-19-test-results-and-their-accuracy https://www.health.govt.nz/our-work/diseases-and-conditions/... Of course if you are testing proper samples from the airways and they come back negative, it’s not very likely these people can infect others through droplets from their airways at that moment. The problem is that they might be in the incubation period but that is irrelevant here. And anyway PCR does not nearly have a 30% false negative rate, I’m not quite sure where you got these stats.

wittyreference 6y ago
Ai et al. https://pubmed.ncbi.nlm.nih.gov/32101510/ https://pubmed.ncbi.nlm.nih.gov/32101510/ analysis of 1014 patients in Wuhan; Yang et al. looked at another 213 in Guangdong. Kucirka et al (https://www.acpjournals.org/doi/10.7326/M20-1495 https://www.acpjournals.org/doi/10.7326/M20-1495) did a pooled analysis of seven other studies and found that "over the 4 days of infection before the typical time of symptom onset (day 5), the probability of a false-negative result in an infected person decreases from 100% (95% CI, 100% to 100%) on day 1 to 67% (CI, 27% to 94%) on day 4. On the day of symptom onset, the median false-negative rate was 38% (CI, 18% to 65%). This decreased to 20% (CI, 12% to 30%) on day 8 (3 days after symptom onset) then began to increase again, from 21% (CI, 13% to 31%) on day 9 to 66% (CI, 54% to 77%) on day 21." You are mistaken.
- tinus_hn 6y ago
  Your first study takes rt-pcr testing as the reference and cannot make statements on its accuracy. Your second study is flawed as indicated by the comments on it, it’s a meta study based on poor data. If you choose a point and go looking for studies to support it, regardless of quality and ignoring studies that do not, that’s not science. And by the way, your studies are about something that is not important here. What is important here is if the patient carries virus particles in his airways so they can infect others, not if they are infected themselves.

wittyreference 6y ago

Ai et al. https://pubmed.ncbi.nlm.nih.gov/32101510/ https://pubmed.ncbi.nlm.nih.gov/32101510/ analysis of 1014 patients in Wuhan; Yang et al. looked at another 213 in Guangdong. Kucirka et al (https://www.acpjournals.org/doi/10.7326/M20-1495 https://www.acpjournals.org/doi/10.7326/M20-1495) did a pooled analysis of seven other studies and found that "over the 4 days of infection before the typical time of symptom onset (day 5), the probability of a false-negative result in an infected person decreases from 100% (95% CI, 100% to 100%) on day 1 to 67% (CI, 27% to 94%) on day 4. On the day of symptom onset, the median false-negative rate was 38% (CI, 18% to 65%). This decreased to 20% (CI, 12% to 30%) on day 8 (3 days after symptom onset) then began to increase again, from 21% (CI, 13% to 31%) on day 9 to 66% (CI, 54% to 77%) on day 21." You are mistaken.

tinus_hn 6y ago
Your first study takes rt-pcr testing as the reference and cannot make statements on its accuracy. Your second study is flawed as indicated by the comments on it, it’s a meta study based on poor data. If you choose a point and go looking for studies to support it, regardless of quality and ignoring studies that do not, that’s not science. And by the way, your studies are about something that is not important here. What is important here is if the patient carries virus particles in his airways so they can infect others, not if they are infected themselves.