A market in Wuhan is pictured in November 2019. Photo credit: Arend Kuester
A senior World Health Organization expert expressed skepticism in 2020 that the COVID-19 pandemic originated in a wet market, according to a U.S. State Department cable obtained by U.S. Right to Know.
The November 20, 2020 cable provides a window into the views of a high-ranking WHO expert about the pandemic’s origin, and contrasts with the certainty of some Western virologists that the pandemic crossed over from wildlife at the Huanan Seafood Wholesale Market in Wuhan, China. This so-called “wet-market” sold farmed and exotic imported animals and animal products, some of which are known carriers of coronaviruses.
The Huanan market has become a focal point in the controversy over the origins of SARS-CoV-2. Many proponents of the hypothesis that SARS-CoV-2 arose naturally say early cases emanated from its wildlife stalls. Hypotheses involving other natural sources or the city’s nearby coronavirus labs have largely been dismissed or ignored.
But the cable reports that Mike Ryan, executive director of the WHO’s Health Emergencies Programme and a top aide to Director-General Tedros Adhanom Ghebreyesus, was not convinced by the wet market hypothesis.
Ryan indicated that there could be other “original sources of the virus” outside of the market, according to a summary of his statements relayed in the cable from the U.S. Mission in Geneva.
“Many of the first cases of COVID-19 … were not associated with the market itself,” the summary of Ryan’s statements reads.”There was likely human-to-human transmission prior to the identification of the cluster at the market.”
Ryan also said that “along with severe hospitalized cases in December 2019, there must have been additional milder or asymptomatic cases,” implying that the virus was silently circulating earlier and that these cases went unrecorded.
WHO affirms market as ‘amplification point’
The WHO’s official stance on Covid’s origins affirms the views expressed by Ryan in November 2020, while underscoring that earlier cases could still have come from China’s wildlife trade.
Both the WHO’s original COVID-19 origins report in 2021 and a more recent preliminary report by the WHO’s Scientific Advisory Group on the Origins of Novel Pathogens (SAGO) state that the wet market may not be the original source of the outbreak.
“These [WHO] reports do not say that the market is the origin of the virus, but it’s an amplification point,” wrote Tarik Jašarević, a spokesperson for the WHO, in an email to U.S. Right to Know. “It’s possible that the animals that were sold there could be the intermediate hosts and how humans got infected, but there were earlier cases without exposure at that market.”
Jašarević underscored the need for more research into the animals sold at the market and the people who worked there.
A summary of a meeting between the European Parliament’s Special Committee on the COVID-19 pandemic at the May 2022 World Health Assembly obtained by U.S. Right to Know further indicates that the WHO does not consider the market the origin of COVID-19.
“The WHO’s assessments show that the earliest cases of COVID could go back to November 2019, given the excess mortality, and that is why they consider that the market in Wuhan is not the origin of this virus,” according to a summary of comments by Jaouad Mahjour, the WHO’s assistant director-general for emergency preparedness and international health regulations.
‘Cryptic’ circulation
In contrast to Ryan and the WHO reports, two recent Science papers by Michael Worobey, an evolutionary biologist at the University of Arizona, and Jonathan Pekar, a bioinformatics graduate student at the University of California San Diego, and colleagues concluded that the pandemic virus originated from wildlife sold at the wet market.
The papers’ authors also argue that even early cases with no obvious connection to the market appear to cluster around it.
“I do not believe that widespread, cryptic circulation of SARS-CoV-2 prior to the first confirmed cases is biologically or epidemiologically plausible,” said Joel Wertheim, an associate adjunct professor at UC San Diego, a coauthor of the papers. “Widespread and cryptic circulation of SARS-CoV-2 is not consistent with the empirical viral genomic diversity.”
Other scientists echo Ryan’s skepticism of the wet market hypothesis, and call into question whether the authors adequately accounted for missed asymptomatic and mildly symptomatic cases.
“I agree with Ryan here,” said David Fisman, a University of Toronto epidemiologist. “There’s no information in the Worobey [Science] paper, or anywhere else that I’ve seen, that says the virus came out of the market, as opposed to the virus being introduced into the market by already-infected individuals.”
Were early cases missed?
Some scientists say that early cases might have been missed because health authorities initially only looked for pneumonia cases that had visited or lived near the market. At the time they didn’t know that most Covid-19 infections were mild or asymptomatic.
The 2021 Joint WHO-China Study confirms that “exposure to the Huanan market was included in the case definition [for Covid-19]” until January 18, 2020.
The WHO SAGO preliminary report also notes that “surveillance systems were not designed to capture a substantial component of the spectrum of illness caused by SARS-CoV-2 infection,” and may therefore have missed mild or asymptomatic infections.
Cables from the U.S. Embassy in Beijing support the WHO’s statements.
A January 7, 2020 cable echoes these reports as well as public descriptions of how early COVID-19 cases were detected, stating that “patients in Wuhan are usually diagnosed in clinics, and if they show matching symptoms, are then sent to Jinyintan Hospital. Medical staff have a general questionnaire that includes whether patients have been to the Huanan market or have had contact with sick people from the market.”
A 2021 editorial by Worobey disputes that a market connection was used to diagnose patients, stating that people were admitted to Jinyintan Hospital based on clinical presentation.
However, a February 20, 2020 cable supports the idea that many mild or asymptomatic cases were missed, stating that the majority of cases in Chongqing were asymptomatic and were only identified because of testing performed for epidemiological studies.
“Chongqing municipal health authorities report that in recent days, most newly confirmed cases have been asymptomatic carriers [bolding in original document] identified through epidemiological studies,” reads the cable.
Chinese press reports support the statements made in the cables and by the WHO.
A February 2020 Eight O’Clock Health News article reports that“in early January, Youfu Hospital found that medical staff and hospitalized patients were infected, but because there was no history of exposure to the South China Market, it did not meet the diagnostic criteria and was not reported. … The [Chinese] Centers for Disease Control and Prevention believes that they underreported cases at the end of December and beginning of January.”
Emily Kopp contributed to this report.
