New Genetic Study of 2019 Wuhan Market Animals May Reveal COVID-19 Origins

LONDON — Scientists investigating the origins of COVID-19 have focused their research on a select group of animals that may have played a role in transmitting the virus to humans. This line of inquiry is designed to help trace the initial outbreak back to its source.

Through the analysis of genetic material collected from the Chinese market where the first outbreak occurred, researchers identified raccoon dogs, civet cats, and bamboo rats as the most likely animals involved. The prevailing theory suggests that these infected animals were brought to the Huanan Seafood Market in Wuhan during late November 2019, setting off the wide-scale pandemic.

According to Michael Worobey, a co-author of the study, the research has shed light on specific sub-populations of animals that may have contributed to the spread of the coronavirus, potentially aiding scientists in locating its natural reservoir.

Worobey, an evolutionary biologist at the University of Arizona, noted that the raccoon dogs present at the market belong to a sub-species that is more commonly found in southern China. This information could lead researchers to investigate the sources and distribution of those animals and push them to sample bats in the vicinity, given that bats are known carriers of coronaviruses like SARS.

Although the study supports the theory that COVID-19 originated in animals, it does not settle ongoing debates regarding the possibility of a lab leak from a research facility in China.

Mark Woolhouse, a professor of infectious diseases at the University of Edinburgh, commented that the latest genetic analysis indicated that the pandemic “had its evolutionary roots in the market.” He emphasized it is highly unlikely that COVID-19 was spreading among humans prior to its identification at the Huanan market. Woolhouse, who was not involved in the research, asserted, “It’s a significant finding, and this does shift the dial more in favor of an animal origin. But it is not conclusive.”

In 2021, a World Health Organization (WHO) expert group determined that the virus probably made the jump to humans from animals, deeming the lab leak scenario “extremely unlikely.” However, WHO chief Tedros Adhanom Ghebreyesus later remarked that it was “premature” to dismiss the lab leak theory entirely.

An investigation by the Associated Press in April revealed that efforts to uncover COVID-19’s origins in China had stalled due to political conflicts and missed opportunities from health officials, both locally and globally.

Scientists acknowledge that it may remain impossible to trace the exact source of the virus conclusively.

The recent study, published in the journal Cell, brought together researchers from Europe, the U.S., and Australia who analyzed data previously released by the Chinese Center for Disease Control and Prevention. This data corpus included 800 genetic material samples collected on January 1, 2020, from the Huanan market, just a day after Wuhan authorities sounded the alarm about an unknown respiratory virus.

While Chinese scientists released the genetic sequences they uncovered last year, they did not specify which animals were potentially infected with the coronavirus. The new analysis employed a technique capable of identifying individual organisms from complex mixtures of environmental genetic material.

Worobey described the data as providing “a snapshot of what was at the market before the pandemic began.” He asserted that genetic analyses like theirs are critical for piecing together how the virus may have initially started to spread.

Though significant, Woolhouse pointed out that the study leaves key questions unanswered. He affirmed, “There is no question COVID was circulating at that market, which was full of animals.” However, the central query remains: how did the virus get there in the first place?

Source: Associated Press