
Originally Posted by
johnst_nhb
There is a bit more to testing than this.
This is always possible. False negatives are a thing in testing. However there are simply too many questions around these cases to know what is going on. Were both tests PCR? Antibody? A mixture?
Testing is far to complex to type out on this board, but its always good to confirm test results. PCR tests are very specific and highly accurate (the same test methodology used in DNA testing) but if you do not have the virus, it would likely be negative (assuming the PCR test is highly specific to unique nucleotide strings.) Antibody tests have a lot of mitigating factors around what they mean.
Suffice it to say a test in and of itself, in general are very specific and generally highly reliable. There is a lot about CV19 that is misunderstood, outright BS and overblown, but testing as a clinical measure really is exempt.