What about the cases that occurred before the fish market erupted?
Outside of the Huanan market, there were other spreads. There are other patients unrelated to the market, some in December. There were other markets. And we know that some of the patients have had connections with other markets. We have to keep working and then our Chinese colleagues have to keep working.
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 over the hypotheses." The route that received the most enthusiastic support was this route – wildlife via a domesticated wildlife link to Wuhan.
What is the next step?
This is straightforward for the animal chain. The suppliers are known. You know the farm name; You know the owner of the farm. You have to go to the farm and interview the farmer and family. You have to test them. You need to test the community. You need to see if there are any animals left on nearby farms, if there are any signs of infection, and if there is any cross-border movement. If the virus is in these southern border states, it is possible that something has moved in neighboring countries like Vietnam, Laos or Myanmar. We are now finding more and more related viruses. There is one in Japan and one in Cambodia, one in Thailand.
For the human side, look for previous cases, for clusters. If possible, check the blood banks for serum. Something like this is going to be sensitive in China and it will take some persuasion, diplomacy and energy to do because, to be honest, finding the source of this virus in China is not a major priority. Think about the Chinese government. Anywhere this virus appears it is a political problem. That is one of the problems and that is clear and obvious to anyone who has looked at this.
Do you have a particular animal that you currently suspect as an intermediate link stronger than others?
It's too high in the air. We don't know if civets were on sale. We know they get infected very easily. We don't know about the mink farms in China or the other fur farms like raccoon dogs, although they are usually bred in a different part of China. That too needs to be followed up.
But if you said which route you put the most weight on, I think the virus would emerge from bats in either Southeast Asia or South China and end up on a domesticated game farm. I've been to many of them and they often have mixed species – civets, ferret badgers, raccoon dogs. These animals could be infected by bats.