This is the quote: "All samples came out to be negative for the presence of SARS-CoV-2 genomes with the exception of March 12, 2019, in which both IP2 and IP4 target assays were positive. This striking finding indicates circulation of the virus in Barcelona long before the report of any COVID-19 case worldwide.".

And no discussion of the obvious possibility that they screwed up the testing, any discussion of whether they could repeat the test on another part of the sample or on the 2019 April-August samples they didn't test, or any sort of attempt at a Bayesian probability analysis.

Pretty ridiculous and shameful, I'd say.

The march 2019 finding is almost certainly a false positive. This is the more interesting and potentially more robust finding from the paper:

"Unexpectedly, analysis of archival samples revealed the increasing occurrence of SARS-CoV-2 genomes in samples from January 15 to March 4, 2020 (Figure 1, panels D and E). Of note, SARS-CoV-2 was detected in sewage 41 days (January 15) before the declaration of the first COVID-19 case (February 25), clearly evidencing the validity of wastewater surveillance to anticipate cases in the population."

This is unfortunately likely to be overshadowed by the march 2019 thing, and I'm surprised that the authors felt comfortable drawing an actual conclusion based off of the 2019 finding and presenting it as "indicating" that widespread circulation was occurring nearly a year before the pandemic hit worldwide circulation. It's not responsible science and might draw doubts on the validity of the other, more interesting conclusion with more evidence to back it up, and rightfully so.

This is one single frozen sample from March 2019 that was positive. Note that subsequent frozen samples from later in 2019 were negative.

Without more data - I'd chalk this up to a false positive or sample contamination.

If you processed archival samples and current samples in the same facility, and on the same machines, your immediate prior should be that your archival samples were contaminated during the assay.

It is never worth wasting your time on an unreviewed preprint outside your expertise. There is tremendous pressure to publish exciting results as an academic, and very weak tools for detecting false results, whether dishonest or just statistically unsound.

Can there be a [PREPRINT] flag or the like added to titles for posts like these on HN? It's really important to keep in mind that preprints are not peer reviewed, and with the increase in interest in healthcare papers on this forum, it would be really helpful to be able to make that clear. It's more likely that the march 2019 sample is a false positive, not a true finding, and in peer review the statistical validity of that finding would be called into question and further validation would be required. Just posting the headline makes it seem as if this is something that has been conclusively determined without the disclaimer that medrxiv itself puts at the top of each of these publications: that preprints aren't peer reviewed and should not be used to inform clinical decisions etc.

Until they show full genome sequencing of a novel strain under controlled conditions, I’d assume this is contamination or a crappy primer set. If you’re running a bunch of PCRs, especially of the same thing, there is a good chance of environmental contamination from older sample (shipping containers labs for testing have split partitions because of this). There has also been times reported where there has been primer contamination at the synthesis company because they were also building SARS-CoV-2 controls.

Also, there is a very easy way to figure out if it’s real - why didn’t they just Sanger sequence the outputs of the RT-qPCR? Such a simple experiment.

Wait, what? The same virus? March 2019? Are we sure that's not an off-by-one typo, or an error?

If that date stands up to scrutiny, wouldn't it call into question everything we thought we knew about the origins and history of covid-19?

The usual reminder for these articles:

This article is a preprint and has not been peer-reviewed. It reports new medical research that has yet to be evaluated and so should not be used to guide clinical practice.

I had it in April 2019 in San Francisco, and have medical history to confirm the symptoms and treatment that worked in my case: steroids plus antibiotics. (Steroids stop the autoimmune reaction, antibiotics help to fight off the bacterial infection which can happen because of steroids). Back then doctors said it was a viral bronchitis "because of some strange coronavirus" which rapidly turned into pneumonia. Three different doctors all were quite puzzled.

So I've been telling ppl for a while that it's been around for longer than is generally believed. I don't think we can say it was "exactly the same" virus, because it constantly mutates. It might have been that I got less virulent and severe version. I also did self-isolate myself on day one of the symptoms, as I do with any cold or flu, which probably reduced the spread from me.

Not saying my experience automatically validates the study, rather that I expect some trustworthy study to eventually confirm that genetically similar strains have been around for almost a year longer.

If anyone's curious about the details, comment below and I'll leave info on how to get in touch.

Even if it were true, and I'm not even mostly convinced it is. Why would this be surprising and why would anyone immediately jump to the conclusion that it's from humans?

I mean Covid-19 didn't just pop out of the air one day, it's been present all along in animals like bats correct? How is it surpising that an animal carcass found it's way into a swage water sample?

Did a couple cursory google searches. Looks like the people funding this paper (SUEZ Spain) are selling a COVID senteniel service to track covid spread through the wastewater[0]. Nothing wrong with research funded by a for profit firm. However, in light of the, well, surprising claims this article makes, and how the article suggests that wastewater surveillance could have caught it that early and doesn't seem to be discussing the limitations of this approach (such as the apparent propensity for false positives...), it's something to keep in mind.

[0]https://www.suez.es/es-es/seccion-comercial/nuestras-referen...

I recently met someone who claimed the symptoms of their SARS-CoV-2 infection started on December 7, 2019, soon after her friends returned from a trip to China. She said the doctors didn't know what to make of her ("lots of bloody mucus", iirc). By February her doctors realized they should test for SARS-CoV-2, and that she tested positive. Her symptoms mostly resolved by March 2020.

The conventional narrative tells us that SARS-CoV-2 started in Wuhan in December 2019 and reached the United States in January 2020 [1]. I think it perfectly reasonable to think this particular weakling virus spread rapidly in China starting in fall 2019, became more virulent as the sun went away and people's vitamin D levels went down. I think the virus blew up in Wuhan, China and northern Italy because of the air pollution [0].

When the medical industry came up with a test and decided to treat the most obvious symptoms of the virus (oxygen saturation levels) instead of the factors that made people vulnerable to the virus, casualties got out of control [2]. Now we've realized that the virus on its own, in a season with adequate sunlight, is basically equivalent to the flue: good at killing old people, not so good for justifying the massive disruptions hoisted upon us all.

Casualties have gone down now that doctors aren't ventilating so aggressively. Imagine what would happen if they realized Vitamin D and zinc deficiency and chronic inflammation and concurrent bacterial infections (TB, etc) are treatable conditions that make people vulnerable to the virus.

[0] https://news.ycombinator.com/item?id=23085633

[1] https://www.cdc.gov/media/releases/2020/p0121-novel-coronavi...

[2] https://news.ycombinator.com/item?id=22993264

Eveything we know about how contagious this virus is would seem to indicate that this has to be a false positive. How would it even be possible for a virus like this to stay "dormant" while circulating for 6+ months before seeing the spread we have now? It seems completely counter-intuitive to me.

It's still a preprint but I would be very wary of such claims.

How specific can Sars-Cov-2 tests are (to other coronaviruses)? Maybe it was a less virulent variant.

After some early discussion, I've yet to see much about testing sewage. Can it be used to accurately establish a relative infection rate?

That's a huge claim without much data to back it up. I am very sceptical.

This seems almost definitely a false positive, surely.