Originally Posted by
OpMidClimax
That's the usual with viral replicant test. In the early days of HIV we didn't test for the virus we tested for the antibodies. We still do but now able to test for viral load. Now HIV patients are classified as undetected with treatment, yet the virus may still be present and without treatment may/ will be detectable again.
The current rapid PCR test is still cumbersome. I have 1000s of hours driving a PCR. The whole contaminated reagent thing... fancy news to say... in reality, the USA is a fragmented system of clinical labs, small and large, some universities and the CDC which is actually not that large and is a research agency not a large scale clinical testing facility. Unfortunately there was no guidance in the beginning on who is to do what and the CDC was forced to produce a commercial test kit, something it never does with a relatively small staff. They were literally doing this by hand sitting around as a team on lab benches trying to make 1000s of "test kits".
Next thing you know you have all hands on deck in a the CDC labs acting as a clinical supplies manufacture, something they never do.
Which doesn’t change the reality. The current PCR tests available are a POS test that was too rapidly developed and too quickly fielded to be reliable, under the same sort of waivers given to the antibody testing, but that’s just part of the problem. Even when they do work they have a low predictive value positive and a low predictive value negative. But even if that could be fixed you have no fix for the fact that they are applicable at all for only a short window of detection. OF COURSE they are going to miss a lot of cases.
And yes, the antibody tests were produced under the same sort of FDA emergency waivers but that’s just it, these tests were produced under THE SAME FDA waivers which gives you no rationale for believing the PCR is any more accurate than the antibody tests and considerable theoretical evidence (not to mention the simple application of Baye’s Theorem) to suggest their predictive value positive AND negative is likely to be BETTER than the PCR testing results.
And I don’t get your “viral load” comparison with HIV testing. I’m unaware of any indication of great numbers of people being chronically infected with coronavirus and whether or not those individuals will be effective transmitters of coronavirus even if they exist.