TAIPEI (Taiwan News) — The team leader of the World Health Organization (WHO) probe into the origins of COVID-19 has told a Danish TV station it is "likely" that patient zero was a staffer at a laboratory in Wuhan.

In January, Peter Ben Embarek, a Danish program manager for the WHO and expert in food safety and zoonosis, headed a team of researchers to investigate the origins of COVID-19 in Wuhan. In March, the team concluded that direct zoonotic transmission to humans was "possible to likely," while introduction through an intermediate host was "likely to very likely," and introduction through the cold food chain was "possible," but introduction through a laboratory incident was "extremely unlikely."

However, in excerpts released on Thursday (Aug. 12) from a documentary released by Denmark's TV 2, Embarek said the outbreak may have been started by an employee at one of Wuhan's many laboratories, after they had been infected by a bat during fieldwork or experiments in one of the facilities. Embarek explained that he believes that infection of a laboratory employee by a bat would be an example of direct zoonotic transmission, and is therefore probable:

"An employee who was infected in the field by taking samples falls under one of the probable hypotheses. This is where the virus jumps directly from a bat to a human. In that case, it would then be a laboratory worker instead of a random villager or other person who has regular contact with bats. So it is actually in the likely category."

Embarek stressed that his team had not found any direct evidence the coronavirus outbreak is related to research on bats being carried out in laboratories in Wuhan. What is known is that horseshoe bats are capable of carrying coronaviruses related to Sars-CoV-2, but they are not endemic to Wuhan and the only people in the city known to have come in direct contact with such bats are the employees of labs found in the megapolis.

Even so, the team found it difficult to discuss the laboratory accident hypothesis with their Chinese counterparts. According to Embarek, it was not until 48 hours before the end of the team's mission that they were able to broach the subject of a possible lab incident.

Embarek said his team was allowed to visit two labs where research has been carried out on bats. In both cases, they were shown presentations on the facilities. They were allowed to ask questions but were not allowed to see any of the laboratory's books or documents.

He pointed out there has been a focus on the Wuhan Institute of Virology (WIV), but added there are reasons to investigate the Wuhan Center for Disease Prevention and Control (CDC). He said the last publication on the subject of bats was from 2013, but that does not mean they stopped doing experiments on the creatures.

When he asked staff from the CDC lab how old the facility was, they responded that they had moved into it in December 2019. The facility is only 500 meters from Huannan Seafood Market, where many of the earliest cases were reported.

Embarek said it is interesting that this move took place on Dec. 2 because that was during the period when the earliest official cases were reported. The WHO expert stated that "when you move a laboratory, it is disruptive to everything."

He added that such relocations involve moving "virus collections, sample collections, and other collections from one place to another." Because of the disruptive nature of such an event, Embarek said it would be interesting to look further into that period and the lab.

The description of the lab leak hypothesis as "extremely unlikely" was a compromise with Chinese authorities to allow the possibility of an accident to be mentioned at all, according to Embarek. Looking back at the process, he believes the laboratory theory could have met resistance because, in fact, some mistakes had been made.

"It's probably because it means that there is a human error behind such an incident, and they are not very happy to admit it. There is partly the traditional Asian feeling that you should not lose face, and then the whole system also focuses a lot on the fact that you are infallible and that everything must be perfect." He then added, "It could also be that someone wants to hide something. Who knows?"

When it comes to the four scenarios listed by the team, Embarek emphasized that one must be careful "not to divide and separate the four completely from each other." He explained that they are very closely linked and there are some situations that could cross over into more than one scenario.

As for the lab accident hypothesis, Embarek asserted it could cover several scenarios:

One of them is that an employee in the laboratory gets infected out in the field while he or she collects samples in a bat cave. Although it is part of the laboratory emission (hypothesis), it is also part of the first hypothesis we have, i.e. direct transfer from bats to humans, and we have considered that hypothesis as a likely hypothesis.