[estaseuropano]

This is a reputable newspaper but I would be careful in taking statements like early circulation in country x or y at face value. There are literally thousands of studies looking back at such data. Even if all of them are done with 100% sound methodology some are by mere statistics bound to find a positive result. Just like you can also dig up studies finding no link between smoking and cancer we have to look at the whole picture that thousands of studies find no such prior circulation.

[estaseuropano]

I can't edit anymore but please also see this comment chain below:

https://news.ycombinator.com/item?id=30083921

All this fuss about THREE positive samples from December 2019, which might be false positives.

[dekhn]

I don't put any credence in this study but I will point out that the likely origin of HIV were probed and they managed to recover HIV samples in blood from 1959. these results are now generally accepted. Note, however, it looks like at least one case was an example of sample mixups or contamination, which is common when dealign with tiny amounts of virus and amplification techniques.

[Arnt]

It was a rare disease. You can't expect a rare disease to be found often.

[estaseuropano]

You are assuming that what they found is indeed a marker of covid-19. It might well be that they found antibodies for another coronavirus that for whatever reason shows on the tests used. There are many coronavira and not all very well researched. Nor is each test precise in each condition, e.g. in the paper they describe how specificity and sensitivity vary depending on the age of the sample, then calculate false positive/negative values using one of those values. Has the test been tested for pregnant women and frozen samples? Might there be other factors, e.g. cross-contamination with some equipment they use?

Its not unusual for even well-done studies to later be revealed as flawed, so its important not to take results of one single study as ultimate truth.

[Arnt]

Actually, what I tried to say is that prior to becoming a common disease, it was a rare disease for a while, and precisely because it wasn't common, expecting it to be found often is unreasonable. Saying that a find is unlikely because most people found nothing is meaningless, because we already know that the virus wasn't common before it became common.

I looked up the test they used, and it's among the better ones.

[mam4]

"supercontagious" and "rare" disease is an oxymoron

[Arnt]

That's right, in the sense that a supercontagious disease cannot stay rare for long. For how long can is stay rare? For how many months? That's a nontrivial question for a diseases such as this, which has both superspreaders and a large number of patients that infect noone.