In early August 2021, a preprint reported a potentially huge discovery. Researchers had looked at samples that were collected as part of measles and rubella surveillance in Italy. They reported the detection of evidence of Sars-CoV-2 genetic material in the samples of 11 subjects taken before the pandemic—with the earliest case going back as far as late summer 2019. This would mean that the virus was circulating in Italy much earlier than December 8, thought to be the date of the first known case in Wuhan.
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The findings were potentially game-changing. They would overturn our understanding of how the Covid-19 pandemic came to be, how it spread, and how the virus itself operated. And this is not the first study to propose that Covid-19 was circulating in Italy long before it was ever reported in Wuhan. In fact, there’s been a whole spate of them, and they’ve been widely covered in the media, including Chinese state media. Authorities in China have been pushing these studies as potential evidence that perhaps the pandemic didn’t even originate in Wuhan after all.
In other words—huge if true. There’s just one problem: All of this science could be riddled with mistakes.
To get their data, the researchers amplified tiny amounts of RNA or DNA in a sample. But the approach is highly susceptible to contamination and notorious for generating false positives. In an earlier report from the same lead author, Elisabetta Tanzi, a professor at the University of Milan, she and her colleagues claimed to find evidence of Sars-CoV-2 in a boy in northern Italy who presented with measles symptoms in November 2019. In the paper, Tanzi and her coauthors write that the lab was “designated as free from Sars-CoV-2.” However, the researchers used a sample from a positive patient provided by a local hospital. That means not only that the virus was in the lab, but that it was amplified to make more of it so it could be used as a control to develop the test, says Michael Worobey, an evolutionary biologist at the University of Arizona. In the later paper, the researchers don’t say they used the same control—but they don’t explain how they got the controls they did use. That means there might have been some virus floating around that they just didn’t know about. “It really does look like a classic false-positive situation,” Worobey says.
A timeline offered by the Italian authors also raises big questions. They constructed a mutational tree of the virus—suggesting that the Wuhan outbreak still took place before moving to Italy in October 2019. That means they’re arguing that the virus came from Wuhan to Italy during the summer of 2019. “It doesn't fit anything that we were watching at the time,” says Andrew Rambaut, a molecular evolutionary biologist at the University of Edinburgh. “It’s like finding an iPhone in a pharaoh’s tomb,” says Worobey—you either have to rewrite history, or you have to consider the possibility that one of the archaeologists dropped their phone. (Tanzi was contacted for this article but declined to comment until the recent preprint had been published in a journal.) Without details of the controls used and corroboration from another lab, Rambaut isn’t convinced the findings hold up at all. “The burden is on them to demonstrate that these sequences are real.”
This early European spread hypothesis has been percolating throughout the pandemic, with a new paper supposedly showing evidence for it cropping up every few months. Every new paper has led to another paper, with all of them sharing a common theme: They are flawed, or rely on unusual methodology, and the majority are placing this early spread in Italy. “People are encouraging each other,” Worobey says. “It’s genuine that people there really are convinced that there was an early outbreak, and they’re going and looking for evidence of it, and perhaps not being very self-critical of the evidence that they’re generating.”
“I don’t see any motive, but I think they’re not independent of each other,” says Rambaut. “Because once this idea has caught hold, people then will go through their stored samples to see what they can find.”
Other studies reporting an earlier detection of the virus in Italy have similar flaws. A study published in August 2020, conducted by Rome’s Department of Environment and Health, reported detecting Sars-CoV-2 RNA in sewage samples taken on December 18, 2019, in the cities of Milan and Turin. These findings raised the suspicions of Alex Crits-Christoph, a postdoc at Johns Hopkins University who specializes in bioinformatic studies of genetic data. The researchers ran three different tests, but only one came back positive. They also devised their own primers, which are used to target specific regions of RNA, despite there being standardized primers for Sars-CoV-2 in use across the world at the time. “That strikes me as a little bit odd,” he says.
On October 28, 2020, a study was submitted to the journal Tumori and was accepted the very next day, “which is indicative of, at the very least, a very rushed peer review—maybe even no peer review,” says Worobey. The researchers looked at the antibodies of volunteers enrolled in a lung cancer screening trial, recruited from all Italian regions, and found that over a hundred of the participants had developed coronavirus antibodies as far back as September 2019. “Our results indicate that Sars-CoV-2 circulated in Italy earlier than the first official Covid-19 cases were diagnosed in Lombardy, even long before the first official reports from the Chinese authorities, casting new light on the onset and spread of the Covid-19 pandemic," the authors wrote. They theorized in interviews that they might have detected a “less transmissible” strain that could circulate without sparking a major outbreak. The paper was widely covered by English-speaking media. But others have pointed out major flaws in the paper. The researchers didn’t take the necessary measures to prevent the detection of other coronavirus antibodies, such as the common cold. “Any antibody test has its false positives, so when you screen a group of individuals in a very low prevalence situation, the majority of positives are going to be false,” says Marion Koopmans, a virologist at Erasmus Medical Center who was part of a WHO team that traveled to Wuhan to investigate the start of the coronavirus pandemic. The study was declared under investigation in March 2021 by the journal, but no corrections were ever made. The WHO requested the samples be retested at other labs. The investigation found that none of the samples contained high enough levels of antibodies to be considered proof of infection.
Another study looked at a skin biopsy from a 25-year-old woman living in Milan taken on November 10, when she came to the hospital suffering from a rash. On closer inspection months later, Raffaele Gianotti, the lead researcher and dermatologist who treated her, found evidence of Sars-CoV-2 molecules in her skin sample. The WHO wanted to investigate the case, but now nobody can locate the female patient, and Gianotti died in March. (The remaining authors on the paper say there is no update on the case.)
Rambaut says these findings “are being used by various parties to support a particular set of narratives.” In particular, they have been covered frequently by Chinese state media, spinning the studies to suggest that China was not the country of origin for the virus. “Wuhan was where the coronavirus was first detected, but it was not where it originated,” said Zeng Guang, formerly a chief epidemiologist at the Chinese Centre for Disease Control and Prevention, at an academic conference in November 2020.
China is keen to shift the blame. “China is still struggling to deal with the fact that it is held responsible for the “original sin” of the outbreak, which undercuts virtually every effort to salvage its image,” Andrew Small, a senior fellow specializing in Chinese foreign policy at the German Marshall Fund told The Guardian. He referred to the reporting of potential other places of origin for the virus as a “propaganda campaign.” In a press briefing, Liang Wannian, team leader of the Chinese side of the WHO team tracing the origins of the pandemic, said the next phase of the enquiry should be conducted in other parts of the world where transmission of the virus had been identified as happening before it was detected in Wuhan. It bears a resemblance to another narrative earlier pushed by Chinese authorities, that the virus might have been brought to China on packaged frozen food.
“There is overwhelming evidence that the Sars-CoV-2 pandemic originated in China, almost certainly in Wuhan,” says Jesse Bloom, a viral evolutionary geneticist at the Fred Hutchinson Cancer Research Center in Seattle, Washington. “Attempts by Chinese state media to argue that the pandemic might have originated elsewhere in the world are clearly scientific misinformation.”
Some scientists are arguing that the theory shouldn’t be discounted just yet, and that the sheer number of papers is worth investigating further, at the very least. “We cannot get around that there are now several pointers from northern Italy,” says Koopmans. In a statement published on August 12, the WHO said it is “working with a number of countries that have reported detection of Sars-CoV-2 in samples from stored biological specimens from 2019.” But it’s clear that the evidence so far isn’t the most robust. “Extraordinary claims require extraordinary evidence,” says Jonathan Stoye, a virologist at the Francis Crick Institute. “I’m not convinced that a dodgy piece of data on top of another dodgy piece of data on top of another dodgy piece of data leads one to a firm conclusion.”
This story originally appeared on WIRED UK.