Multiple studies in different countries point to the possibility of COVID-19 having popped up before the outbreak in China’s Wuhan, and the job of virus origins tracing should not be fixed on one place, Chinese health experts said at a press conference held in Beijing on Thursday.
Answering a question raised by the Global Times, the experts declared that a comprehensive probe needs to be expanded to more countries, including the US.
Liang Wannian, team leader of the Chinese side of the WHO-convened joint expert team on origins tracing, said that the results of initial studies by scientists in varied countries, showed that the coronavirus could have occurred in multiple places in the world “before the time we knew its existence”.
An Italian woman’s skin biopsy detected genomic sequence of the coronavirus in November 2019. And wastewater samples collected on November 27 in a Brazilian city found genetic materials of the coronavirus. Donated blood check-ups in nine US states found 106 blood samples, ranging from December 13, 2019, to January 17, 2020, tested positive for coronavirus antibodies. A French patient’s throat swab tested positive for antibodies on December 27, 2019. Wastewater in Barcelona tested positive for the coronavirus’ nucleic acid in January 2020. Nine out of 24,000 blood samples taken in the US’ 50 states, tested positive for antibodies between January 2 and March 18, 2020, Liang said.
The long list of scientists’ studies indicates that Wuhan might not be the first place of the coronavirus’ inception, Liang said.
He suggested the spread of the coronavirus could be very complex, and the virus could be transmitted through an infected person or animal, which later causes more infections among groups of people, or cross-infections between animals and people.
The infection chain, including how the virus jumped from animal to human, or from an animal to an object and then to human, what are the relations of those links and how they influenced the infection chain, would shed light on new directions for origins tracing, Liang said, noting studies of early patients, bio samples, genomic sequences, natural hosts, intermediate hosts and cold chain infection, cannot be conducted without joint efforts of multiple places worldwide.
To explore trans-species infections and the coronavirus’ global spread, research work ought to be done on its evolution in animal hosts, trying to identify the zoonotic source of the coronavirus and the route of its introduction to human being, including the possible role of intermediate hosts.
Viruses are common enemy faced by all human beings, and the complicated task of origins tracing requires cooperation of scientists across the world, of governments and all people, Liang said.
Wang Chen, an Academician of Chinese Academy of Engineering, said at the press conference that the findings also suggest the possibility of multiple sources of the coronavirus.
“If we really want to find the origins of the coronavirus, we should not be restricted in our vision but should broaden it,” said Wang, who is also the chancellor of the Peking Union Medical College.
It is important to get the direction of origins tracing — multiple-site, multiple-orientation and systemic research and study, Wang noted.
Chronicle of COVID-19 outbreak Graphic:GT
