A seafood market, a virology lab, and a mountain mine, the events that occurred in these locations in China may be significant in understanding how a small cluster of coronavirus infections spread throughout the world. Because, over a year and a half after the global health crisis began, policymakers and scientists are still arguing what caused it. If you're going to investigate the cause of a pandemic, you should do it as soon as possible. That appears to be a tall order right now. This is due to the extremely restricted access to Wuhan.
The most common theory is that the virus came from bats. Jumped from one animal to another, then back to us. And it's possible that the transition to humans took place in Huanan Seafood Market.
According to some scientists, the virus may have accidentally leaked from a lab 10 miles away. And both of these Wuhan locations are becoming increasingly linked to a location over 1000 miles away in Yunnan province's mountains.
As a result, experts travelled to these critical locations to dissect what is known about the coronavirus in order to better understand how the worldwide pandemic began.
Stop number one, the Huanan Seafood Market, December 31st, 2019. This is the day the WHO learned about a cluster of pneumonia cases in Wuhan. And increasingly, the focus was on the market. The complex spans an area that's the size of nine football fields and has over 600 stalls. About 10 of those were selling wild animals like bamboo rats, hedgehogs and hog badgers. These wildlife are raised on farms, sometimes in crowded conditions where it's easy for animals to spread viruses back and forth between each other and the viruses start to mix and match and can change.
Some wildlife that are receptive to coronavirus infections are consumed in China, either for food or used in traditional medicine. These animals are shipped to urban markets where they are sold sometimes live and butchered onsite. And all this contact with live possibly infected animals or the infected fresh meat has become a major concern in recent years. And in Wuhan, many of the first cases were either vendors who worked at the market, or people who had shopped there. By January 1st, Chinese authorities shut the place down.
Well, originally Chinese authorities did feel that it possibly came from the Huanan Market and from wild meat of some sort. About three weeks later, scientists in Wuhan and Beijing published a pivotal paper in the medical journal, The Lancet.
In this paper scientists showed some data of the early cases were people who hadn't been at the market. More than a year later, there was new data to piece together a clearer picture, that's because China allowed a group of international scientists to come to Wuhan for several weeks to visit the market and hospitals.
A team from the WHO that visited China also learned going through the data that by mid to late December, the viruses that were infecting people were genetically different enough that they knew it wasn't all coming from the same place. The WHO said the presence of early cases not linked to the market could suggest that it was not the original source of the outbreak.
And increasingly, one place a team visited is at the center of another hypothesis, the Wuhan Institute of Virology. This is a world-class Institute with high security laboratories and does a lot of work with scientists outside of China, very vibrant collaboration before the pandemic. They would travel to caves where bats are known to roost and take samples, and then study them in their lab. These bat coronaviruses and pathogens are cataloged in databases. The researchers used this library of information to compare it to blood samples and oral swabs from patients in Wuhan. And about a month after the market was closed, these researchers discovered that COVID-19 had a 96.2% genetic match with the bat coronavirus that the institute had found back in 2013.
Scientists around the world consider this a breakthrough in the search for COVID-19 source, because it strongly indicated that it could have originated in bats. This laboratory studies bat coronaviruses in Wuhan, was an obvious question, could it have escaped? And even the Institute's own researchers asked that question and went and did their own research.
As questions swirled around a possible accident at the institute, it's top bat coronavirus expert said the virus didn't leak from her labs, and none of its staff have tested positive for COVID-19. These are not the first times that we've had a world exposed to virus as a result of failures in a Chinese lab.
Last year, what started out as a basic scientific question got politicized with a lot of finger pointing at China yet there was no evidence presented. And there was also limited access to data during the WHO-led team's trip to Wuhan. One of the stops was the virology institute. They asked questions and they had a tour, but they didn't get any firsthand look at databases, medical records, any sort of raw data which would have shed light on whether the virus could have escaped or not.
Almost a week later, scientists summed up their findings at a press conference. They said the spillover from an intermediate host to humans was likely to very likely, and as for questions surrounding the lab. The findings suggest that the laboratory incident hypothesis is extremely unlikely. But later, the WHO chief said the team didn't sufficiently examine the lab hypothesis, and called for a fuller probe. Three months later after that press conference, a group of leading virologists and epidemiologists wrote a letter saying there were no findings in clear support of either a natural spillover or a lab accident. This group of people is not saying that they believe it came from a lab. What they're saying is that there's not enough evidence to rule it out.
Scientists investigate hypotheses and they rule them out one by one. And they just said that process hasn't been able to happen and it needs to happen. China says it's cooperated fully with the effort to search for COVID-19's source and has urged the WHO to investigate early cases in other countries.
And one place that could provide some new evidence for both hypotheses, Yunnan. It's China's Southwestern most province and home to many coronavirus-carrying bats. And could set the stage for where the investigation into the origin of the virus could go next. It's clearly an area where coronaviruses are circulating, including coronaviruses that are very closely related to SARS, the epidemic in 2003.
Researchers from the Wuhan Institute of Virology went to Yunnan to study large bat populations inside caves. In these crowded spaces, viral strains can mix together, and become the building blocks of coronavirus that then jump to humans. And at the same time, there are wildlife farms there that supply animals to Wuhan.
Scientists say, this could explain how a virus from a bat cave leapt to an intermediate host then made its way to the market. There was also a mine in Yunnan where scientists from the institute spent some time from 2012 onwards. It's where six miners who'd been clearing bat droppings had gotten sick, and developed an unexplained pneumonia. Three of them died. So in 2013, scientists from the Institute went to the cave to collect samples from bats.
A virus from one of these samples turned out to be that 96.2% genetic match that was discovered by the institute, inhaled as a big break during the early days of the pandemic. It took months for the institute to reveal that the bat coronavirus samples were from the mine, and that there were sick miners.
The failure to describe it more became kind of a touchpoint for people who wanted more information from the laboratory about the viruses they do have, and what work they've been doing with them. Then, there was another allegation about the institute that surfaced more than a year later. What US intelligence officials learned is that there were three researchers who became ill enough to seek hospital care. They had symptoms that were like COVID, but the symptoms like COVID are also like flu symptoms. And flu was definitely circulating in Wuhan at that time.
Four days after the intelligence report about the sick lab workers, the Biden administration ordered a US intelligence inquiry into the two scenarios. China said the report was untrue. Some people don't believe China and say this has to be a coverup. Others say we just need to verify, though that's what we do in science. It really does boil down to a question of transparency.
So for any progress to be made in the origins of the virus, it'll ultimately require more data, and fuller access to where it was first detected in China.