In this News-Medical interview, we spoke to Professor Diana Bell about the illegal wildlife trade and how we could prevent future pandemics by stopping it.
What provoked your research into zoonotic diseases?
My interest began with wildlife diseases. The first species I worked on was the rabbit. I was interested in the evolution of a rabbit virus which involved many different vectors and host-parasite evolution. That was my first disease, which of course is not zoonotic.
As I was working on diseases like this, we discovered that a number of the critically endangered species that we were trying to save around the world were being severely affected by novel diseases or parasites. The next disease I worked on was the parasitic infection of a critically endangered pigeon, the pink pigeon, in Mauritius. I had a Ph.D. student looking at that for several years, and we are still investigating it. That is a protozoan parasite.
Whilst we were doing the pink pigeon work in Mauritius, the parasite jumped to finches in the UK. Then it spread across Europe, and also jumped into the US to kill finches. It was an interesting coincidence that something that we were working on then became a major problem on the continent.
During the early 2000s, I was working on the illegal wildlife trade in Southeast Asia. When SARS hit in 2003, we just happened to have a Ph.D. student working on the conservation of civets in Vietnam. These were identified as a possible source of SARS-CoV, and we seemed to be the only people that knew anything about civets.
We emphasized at the time that we believed that the spillover to humans had not come from civets in civet farms. We said the spillover had probably occurred in the markets where these animals were being illegally sold, traded, and mixed. We also emphasized the need to screen these animals in the wild to see if they are carrying that virus in the wild, rather than before they enter the wildlife trade system.
I gave a talk about this research at the Royal Society ‘Emerging infections: what have we learnt from SARS?’ meeting back in 2004, where we highlighted the fact that SARS would happen again whilst the illegal wildlife trade was happening and different species which would not normally mix were mixing. Of course, pathogens occur naturally, but it was also a wildlife biodiversity crisis. The wildlife trade is actually a greater threat in Southeast Asia to biodiversity than deforestation currently.
Before the SARS-CoV-2 outbreak, we worked on H5N1 (highly pathogenic avian influenza) which was occurring throughout the region, and globally, it is still happening.
All this research has led to my interest. I have an interest in the impacts on both human health, but also on biodiversity.
Please can you give us some insight into the wildlife trade worldwide?
It is a global problem and it is particularly bad in Asia, especially China. The demand from that region for wildlife has meant that illegal trade is now bringing in animals from Africa and South America to Southeast Asia. Instead of decreasing, the illegal wildlife trade to Southeast Asia and China has increased since SARS-CoV. Animals that were not in the trade 15, 16 years ago are now heavily traded and have been brought to the brink of extinction.
But in Southeast Asia, there has been a shift from the consumption of wildlife at home. The hunter used to go out, kill an animal for our family meal and it would be eaten locally. There has been a shift from home consumption to selling those animals to illegal wildlife traders to get more money.
This trade was then associated with increased affluence. Some of these wildlife food restaurants in Southeast Asia were frequented by the middle class and wealthier people. This is not food to keep the family fed, this is a different kind of food. Some of this comes from alleged medicinal qualities. Everything from turtles to carnivores to snakes, all sorts of animals are consumed in that way.
In Africa however, it is slightly different. There is the bushmeat trade, and some of that really is to keep the family fed. However, some animals from Africa are going to China, as are animals from South America. The illegal wildlife trade is worldwide.
The wildlife trade also comes the other way through the demand for exotic pets from Europe, North America, and other countries. People want exotic snakes, other exotic…