WHO lead investigator Peter Ben Embarek told CNN in a wide-ranging interview that the mission had found several signs of a wider spread of 2019, including establishing for the first time that there were more than a dozen strains of the virus in Wuhan already in December. The team also had a chance to speak to the first patient the Chinese authorities said was infected, an office worker in his 40s, with no notable travel history, reported infected on December 8.
The slow emergence of more detailed data collected on the long-awaited WHO trip to China may increase concerns expressed by other scientists studying the origins of the disease that it may have spread in China long before its first official appearance in mid-December. .
Embarek, who has just returned from Wuhan to Switzerland, told CNN: “The virus was circulating widely in Wuhan in December, which is a new discovery.”
The WHO food safety expert added that the team was presented by Chinese scientists with 174 cases of coronavirus in and around Wuhan in December 2019. Of these, 100 were confirmed by laboratory tests, he said, and 74 others through diagnosis patient’s clinical symptoms.
Embarek said it is possible that this higher number – probably severe cases that were seen by Chinese doctors in the beginning – means that the disease may have hit about 1,000 people in Wuhan that December.
“We haven’t modeled this since,” he said. “But we know … in approximate numbers … of the infected population, about 15% end up with serious cases and the vast majority are mild cases.”
Embarek said the mission – which included 17 WHO scientists and 17 Chinese scientists – expanded the type of genetic material for the virus they examined in the first cases of coronavirus that December first. This allowed them to analyze partial genetic samples, rather than just complete samples, he said. As a result, they were able to assemble 13 different genetic sequences for the SARS-COV-2 virus from December 2019 for the first time. The sequences, if examined with broader data from patients in China in 2019, could provide valuable clues about geography and the timing of the outbreak before December.
Embarek said, “Some of them are from the markets … Some of them are not linked to the markets,” which includes the Huanan seafood market in Wuhan, which is believed to have played a role in the first spread of the virus. “This is something we discovered as part of our mission … part of the interaction that we all had together.”
Variants pose bigger questions
Changes in the genetic makeup of a virus are common and usually harmless, occurring over time as the disease moves and reproduces between people or animals. Embarek refused to draw conclusions about what the 13 strains might have meant for the disease’s history before December.
But the discovery of so many possible variants of the virus may suggest that it has been circulating for longer than just that month, as some virologists have previously suggested. This genetic material is probably the first physical evidence to appear internationally to support such a theory.
Prof. Edward Holmes, a virologist at the University of Sydney, Australia, said: “As there was already genetic diversity in the SARS-CoV-2 sequences sampled in Wuhan in December 2019, it is likely that the virus has been circulating for a longer time than that month alone. ”
Holmes, who has studied the virus at length, said these 13 sequences could indicate that the virus had spread for some time undetected before the December outbreak in Wuhan. “This data fits in with other analyzes that the virus appeared in the human population before December 2019 and that there was a period of enigmatic transmission before it was first detected in the Huanan market.”
The WHO team held a three-hour news conference alongside its Chinese colleagues in Wuhan to present its findings last week. Since then, more details have been slowly emerging as to the precise data to which they had – and sometimes did not have – access.
Embarek said the mission received analyzes from Chinese scientists of 92 suspected Covid-19 cases between October and November 2019 – patients who had symptoms similar to Covid’s and were seriously ill. The WHO team requested that these 92 be tested in January this year for antibodies. Of these, 67 agreed to be tested and all were negative, said Embarek. He added that further testing is needed, as it is not yet clear whether the antibodies remain in former Covid-19 patients until a year later.
However, the way these 92 cases spread over these two months and geographically across Hubei also puzzled Embarek, he said. Embarek said that the 92, as presented to the WHO team, did not appear in groups, as is common in disease outbreaks. Instead, they were spaced out in small numbers over the two months and across Hubei province, where Wuhan is located.
“There was no crowding in specific places,” he said. “That would have been discovered.” It is not yet clear whether these 92 cases were associated with the coronavirus, and what this lack of clustering may indicate.
Embarek also said the mission was able to serve the first Covid-19 patient that China said it knew. A Wuhan resident in his 40s, the man was not identified and had no recent travel history.
“He has no ties to the markets,” said Embarek. “We also talked to him. He has a very – in a way – boring and normal life, no mountain hikes. He worked for a private company.”
China promises cooperation
China has promised transparency with the WHO investigation. In response to criticism from the US that it should provide access to its previous raw data, the Chinese Embassy in Washington DC said: “What the US has done in recent years has severely undermined multilateral institutions, including WHO, and severely undermined cooperation international in COVID-19, “said a spokesman for the Chinese Embassy in the United States in the statement.
“But the United States, acting as if none of this has happened, is pointing the finger at other countries that have faithfully supported WHO and WHO itself,” the statement continued.
The WHO team hopes to return to Wuhan in the coming months to continue its investigations, Embarek said, although he has been unable to provide specific dates for a confirmed trip.
He said the team hopes to urgently examine biological samples that experts say are not available to them on this first trip, specifically thousands of samples from the Wuhan blood donor bank that date back two years.
“There are about 200,000 samples available there that are now protected and can be used for a new set of studies,” said Embarek. “It would be fantastic if we could [work] thereby.”
Embarek said that there may be technical difficulties in accessing these samples. “We understand that these samples are extremely small samples and are used only for litigation purposes,” he said. “There is no mechanism that allows routine studies with this type of sample.”
He said that some other biological test samples that may have proved useful during the Wuhan mission were also not available to them. “Many of the samples were discarded after a few months or weeks, depending on the purpose of the collection,” he said.
Embarek said the circumstances of the mission – of intense quarantine periods and social detachment – have led to some frustrations, along with the global scrutiny of his conduct and discoveries.
“We worked together for a month between two groups of a large group of scientists,” he said. “And, of course, it is from time to time … you – as always, among passionate scientists – you have a heated discussion and then an argument about this and that.
“Remember, we had the entire planet on our shoulders 24 hours a day for a month, which does not make work among scientists any easier.”