The WHO mission to China to uncover the origins of Covid-19 has failed to identify the source of a pandemic which has swept across the world, but the team has ruled out the Wuhan lab-leak theory propagated by former US President Donald Trump.
The coronavirus is unlikely to have leaked from a Chinese lab and is more likely to have jumped to humans from an animal, a World Health Organization expert has said.
WHO food safety and animal diseases expert Peter Ben Embarek made the assessment at the end of a visit to the central Chinese city of Wuhan on Tuesday, where a team of scientists is investigating the possible origins of the coronavirus.
The first cases were discovered in the city in December 2019.
Former US president Donald Trump has also frequently repeated a controversial theory that a lab leak may have been the source of the pandemic.
'Virus could have been circulating elsewhere before Wuhan discovery'
The virus that causes COVID-19 could have been circulating in other regions before it was identified in the central Chinese city of Wuhan at the end of 2019, a top expert at China's health authority said on Tuesday.
Liang Wannian, an expert with China's Health Commission, also told a press briefing at the end of a nearly one-month visit to Wuhan by a World Health Organization-led team that there had been no substantial spread of the virus in the city before the late 2019 outbreak.
Experts believe the disease – which has killed more than 2.3 million people worldwide – originated in bats and could have been transmitted to humans via another mammal.
The Wuhan Institute of Virology has collected extensive virus samples, leading to allegations that it may have caused the original outbreak by leaking the virus into the surrounding community.
China has strongly rejected that possibility and has promoted other theories that the virus may have originated elsewhere.
Earlier in May 2020, a French hospital that retested old samples from pneumonia patients had discovered that it had treated a man who had Covid-19 as early as December 27, nearly a month before the French government confirmed its first cases.
The team is considering several theories for how the disease first ended up in humans.
“Our initial findings suggest that the introduction through an intermediary host species is the most likely pathway and one that will require more studies and more specific, targeted research,” Embarek said.
“However, the findings suggest that the laboratory incidents hypothesis is extremely unlikely to explain the introduction of the virus to the human population,” Embarek said.
Transmission through the trade in frozen products was also a likely possibility, Embarek said.
READ MORE: 2020 rewind: Timeline of Covid-19 pandemic
WHO team visits
Along with the institute, the WHO team that includes experts from 10 nations has visited hospitals, research institutes, a traditional market tied to the outbreak and other sites on their visit.
The visit by the WHO team took months to negotiate after China only agreed to it amid massive international pressure at the World Health Assembly meeting last May, and Beijing has continued to deny calls for a strictly independent investigation.
Chinese authorities have kept a tight hold on information about the possible causes of the pandemic that has now sickened more than 107 million people and killed more than 2.3 million worldwide.