Well maybe positive but not necessarily able to infect. If they used PCR tests it could give positive on broken up inactivated viruses for awhile after you cleared the infection
If I could upvote this a million times I would. If 50% of those tested positive are asymptomatic, then a good first-order approximation is that the false positive rate is 2x the actual prevalence, and the results say very little about prevalence that actual hospitalizations don't say.
People, and to a large degree the media, are putting a huge emphasis on testing, not always in a way sensitive to the essential difficulty of evaluating test accuracy, especially in epidemiological settings.
Would it be disingenuous to say that false positives in the current case fatality rate would bring the rate down because hospitals are using symptoms combined with PCR for deaths?
From what I've heard, at least in some areas, a Covid test is often performed only after a (usually very fast) flu test is performed. So a death resulting from a person negative for flu but also false-positive for Covid would seem very unlikely. As would any death of this sort from a person who came up positive. Much more likely would be that false positives cluster among those with mild or no symptoms (with the mild symptoms instead coming from a more mundane infection)
If false positives were pushing the published death rate up, it's important to remember there are also deaths among people infected but never tested that would be pushing the rate down. I don't know if they would cancel each other out though. I would however really like to see published data from the CDC about reported pneumonia deaths just prior to the "official" outbreak to see if there was an otherwise unexplained increase.
I don't know but the problem is more with low infection rates. Suppose you have 3% false positives and 3% false negatives, and 0.1% of people are infected.
The false negatives will be 3% of 0.1%. The false positives will be 3% of 99.9%. You exaggerate your infection rate by about 30X even though the test is equally inaccurate in both directions.
