Inaccurate data led to belief that covid-19 was circulating ahead of time

BarcelonaThe World Health Organization (WHO) had recently declared that SARS-CoV-2 was the virus causing a worldwide pandemic (March 11, 2020) when several teams of researchers warned that it was already circulating at least a year earlier. This is the case of the Barcelona sewage study, which placed the origin at least in March 2019; the high impact of covid-19 in lung cancer patients which placed it in September 2019 in Italy, or a late 2019 study in the United States which stated that the coronavirus was already "widely disseminated" long before it was formally detected. A final study, from France, placed its origin in November 2019 but with a single case. All four papers were trying to find whether the virus had spread from the Chinese city of Wuhan or, instead, had emerged in different parts of the world. With the passage of time, none of the four papers holds up.

The work that attracts more attention and was referenced the most by fellow scientists is the one on the wastewater of the city of Barcelona, which the ARA echoed, making it clear that other experts were skeptical and that it had not yet been published in any scientific journal. According to the authors' conclusions, coordinated by Albert Bosch, of the Enteric Virus Group of the Universitat de Barcelona, the virus was already circulating in the city in March 2019, a year before the pandemic was declared. A year after publishing the alert, no one in the academic world takes that news seriously. Coinciding with the anniversary, biotechnologist Xavier Dengra published a critical analysis on Twitter. Dengra recalls that, in fact, it is a "pre-published" study included in a reservoir and that in no case had passed the mandatory peer review. Even so, and despite the fact that it was never published in any scientific journal of impact, the study had an important media echo.

Dengra considers that it is not deserved. The work "was not definitive and had not been validated by other scientists or any editorial board". Alina Chan, a researcher at the Broad Institute of MIT and Harvard University, considers it "not very credible". The problem lies in the fact that, of the entire series of samples studied, from January 2018 to December 2019, in only one case was a "hint" of virus genome detected. Chan, as well as other researchers, reproaches that the analysis was inconclusive and the data was "very imprecise". "There was no way to be sure that it was SARS-CoV-2 or any of its precursors", says the researcher. Despite the forcefulness of the criticism, Dengra regrets, the work has not been removed from the repository nor have the authors given any explanation. "Subsequent papers by the same researchers do not even cite it in their bibliography", he exclaims.

A similar case is that of a study from the University of Parma (Italy). The authors used an internal test that had not been validated to claim that 14% of cancer patients in Italy in September 2019 tested positive for covid. Or the case where, according to CDC (US Centers for Infectious Disease Control) predictions, 2% of people living in large cities on the US east coast tested positive for coronavirus in December 2019. In fact, as has subsequently emerged, the figure is in line with the expected false-positive figure. In fact, just this month the WHO released a statement saying that it had provided an "independent assessment" by international laboratories of samples from 2019 in which the virus was detected, specifically citing the case of Italy.

The French study, like other Italian studies published during 2020, refers to single cases in which the analysis of the coronavirus genome is incomplete or irregular. In light of this work nearly a year after its publication, it appears that covid-19 did indeed emerge from Wuhan, although it remains to be determined whether it escaped from a laboratory or was of animal origin.