What about the cases that appeared before the outbreak in the seafood market?
There was other spread going on outside of Huanan market. There are other patients who have no links to the market, quite a few in December. There were other markets. And we do know that some of the patients had links to other markets. We need to do some further work, and then the Chinese colleagues need to do some further work.
When we sat down as a group, the China team and the W.H.O. team on the last full day of work, and said, “Let’s go through the hypotheses,” the one that received the most enthusiastic support was this pathway — wildlife, through a domesticated wildlife link, into Wuhan.
What is the next step?
For the animals chain, it’s straightforward. The suppliers are known. They know the farm name; they know the owner of the farm. You’ve got to go down to the farm and interview the farmer and the family. You’ve got to test them. You’ve got to test the community. You’ve got to go and look and see if there are any animals left at any farms nearby and see if they’ve got evidence of infection, and see if there is any cross-border movement. If the virus is in those southern border states, it’s possible that there’s been some movement across neighboring countries like Vietnam, Laos or Myanmar. We’re finding more and more related viruses now. There’s one in Japan and one in Cambodia, one in Thailand.
For the human side, look for earlier cases, for clusters; look in blood banks for serum, if possible. Anything like this is going to be sensitive in China, and it’s going to take some persuasion and diplomacy and energy for them to do that because, to be honest, looking for the source of this virus within China is not a great, high priority I think for the Chinese government. Anywhere this virus is shown to emerge is a political issue. That’s one of the problems, and that is clear and obvious to anyone who has been looking at this.
Do you have a particular animal that you suspect right now as an intermediate link, more strongly than others?
It’s too up in the air. We don’t know if civets were on sale. We know they are very easily infected. We don’t know what the situation is with the mink farms in China or the other fur farms, like raccoon dogs, even though they’re normally farmed in a different part of China. That needs to be followed up on, too.
But if you were to say which pathway would you put the most weight on, I think the virus emerging either in Southeast Asia or Southern China from bats, getting into a domesticated wildlife farm. I’ve been to many of these, and they often have mixed species — civets, ferret badgers, raccoon dogs. Those animals would be able to get infected from bats.
