4 ms·

I don't think your percentage is correct. It depends on the PCRs target gene, the quality of the samples and the quality of the machine used. They are using rev

• 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."