Ammon News - The long-awaited trip, which was delayed by China, is part of what will be a lengthy process of piecing together the virus’s origin.

Early data from unpublished studies suggests that Covid-19 could have been circulating for weeks outside the city of Wuhan, where the virus was first identified, according to the Chinese lead of the World Health Organization team that released first details of its fact-finding mission into the origins of the virus, NBC reported.

"This indicates the possibility of the missed reported circulation in other regions," said Dr. Liang Wannian, the Chinese lead of the international team, which includes the WHO, during a press conference.

The first cases of a pneumonia-like illness were reported in Wuhan, a city of some 11 million people on the Yangtze River in central Hubei province, in December 2019, according to the NBC.

The team arrived in Wuhan on Jan. 14 and after two weeks of quarantine, visited key sites such as the Huanan seafood market, which was linked to an early cluster of infections, as well as the Wuhan Institute of Virology, which has been involved in coronavirus research.

Earlier, member of the WHO expert team said the Chinese side granted full access to all sites and personnel they requested — a level of openness that even he hadn’t expected, the Associated Press reported.

Peter Daszak said team members had submitted a deeply considered list of places and people to include in their investigation and that no objections were raised.

“We were asked where we wanted to go. We gave our hosts a list ... and you can see from where we’ve been, we've been to all the key places," Daszak said.

China has faced heavy criticism for allegedly downplaying the severity of the initial outbreak of the mysterious, pneumonia-like illness in late 2019, and for not acting quickly enough to alert the WHO of evidence of human-to-human transmission, the NBC reported.

The WHO's team landed in Wuhan last month, more than a year after Covid-19 was first detected there. The long-awaited trip is part of what will be a lengthy process of piecing together the virus’s origin to answer key questions about the pathogen and how to prevent similar — and possibly worse — future outbreaks.

Two members of the 15-strong WHO delegation of scientists were at first denied entry to China and kept in Singapore after testing positive for coronavirus antibodies, but were later released.

The suspicion about China’s handling of the outbreak came after its problematic response to the 2003 SARS pandemic, when it was found that Chinese officials had suppressed and deliberately withheld information from the public. The WHO has praised China early for its efforts to contain the Covid-19 outbreak, but questions still remain about where and how the pathogen emerged.