[timhigins]

The truth is that these current tests (rt RT-PCR) are not completely accurate and may only have a true positive rate of 60-70%. See Discussion section of: https://pubs.rsna.org/doi/10.1148/radiol.2020200642

Additionally, people who are asymptomatic can test negative on all of their tests and only be diagnosed via other means. See Figure 1 here: https://link.springer.com/content/pdf/10.1007/s11427-020-166...

[projektfu]

You have that a little backwards. The positive predictive value in the discussion is for CT. rtPCR is being used as the definitive test but it lacks sensitivity so it has false negatives. The 59% rate for rtPCR positive suggests that they are missing cases that CT might catch. However, the CT findings are not “pathognomonic” meaning that other conditions can cause the appearance of viral pneumonia (such as influenza).