Marie Toorians is a PhD Candidate with the University of British Columbia studying bovine tuberculosis in South Africa. Marie looks at how this disease moves between different animal species and where it could be harboured in the environment with the aim of decreasing the spread of tuberculosis.

My name is Marie Toprians and I'm a PhD candidate at the UBC Biodiversity Research Center with the Jonathan Davies lab. My research is about how animals share diseases and how the loss of species can affect the disease outbreak potential of this community of different animal species. Specifically I'm interested in bovine tuberculosis which is endemic in sub-Saharan Africa where I study, but [it's also endemic] in a lot of other countries in Europe and in the Americas where it affects cattle.

In South Africa it is maintained by the reservoir Buffalo. The buffalo have this disease, but they don't really get affected by it, which is a problem because they just roam around the site [the Kruger National Park], the whole park basically and then they can give this disease to other animals, for example for lions. This is a big problem because whenever they [lions] hunt a buffalo because [maybe] it [the buffalo] is a little sick, so it's slower and easier to catch, it [the lion] will contract the disease by eating its meat. The lion actually [will] get affected by it, so it'll die. These are very problematic events [because] this is an at-risk species and we don't want them to die off from a disease.

Lions they can contract a disease through hunting, however there are lots of species in the Kruger National Park that have this disease and they do not come into direct contact with the buffalo, so we're thinking that they must contract it through the environment. For example they share water holes, so it might be in the water or around the water, and so we were looking at the soil around the water because maybe when they drink some water some saliva dripped out, and it could have dropped onto the soil or in the vegetation. Then [maybe] the next animal that would have a nibble on that vegetation might be able to contract it.

We took samples from around the water hole of the soil, then we extracted the DNA in the lab, and then we checked for the presence of this bacterium to see if it was actually there. We also put up camera traps at these sites to see which of the animals were visiting and could have potentially shed this disease.Bovine tuberculosis has been found before, in the soil on farms in Michigan, in Ireland, and in wildlife parks in Spain. So it has been shown before that the bacterium can reside in the soil and it can stay there for quite a long time. We're hoping to prove the same thing in South Africa. If we do find it we can look at the vegetation and types of soil in which we find it most to see what we can do and what management can do to prevent the spread between animals.

I've always been interested in animal behavior, ecology, and especially the way the populations behave. A diseaseis actually a way to connect animals because it makes them indirectly compete with each other. I think diseases are are very interesting to study for other reasons too, for example look at the bird flu. Whenever there was an outbreak it would cause massive callings or selective slaughtering of chickens which cost enormous economic losses. With the environmental burden that livestock already has it is especially important to prevent these sort of problematic losses. Also think about things like covid and a swine flu. Whenever a farm has a disease like that, it can spill over into the human population and cause major damage as we have seen in the [covid] pandemic.

One time some tourists in the Kruger National Park were teasing a breeding herd of elephants with a lot of young calves. Obviously the male bull got very upset and started chasing the car and then stormed out to our field site where we were working. We had to just drop everything and run to the car, but my assistant actually ran back to save the moisture meter. Which I did not ask her to do... so we saved it. Fortunately all of our equipment was safe they didn't touch it. When we picked it up later everything was fine, but when we tried to drive back to the site some of the elephants were still there and they didn't see the difference between cars. They thought our car was the the bad car that was teasing them or assaulting them in their eyes. One of the male bulls just came running towards our car and I had to reverse. Well I've never reversed that fast in my life. Fortunately I found a little spot where I could turn a car and drive away, but the elephant was like right there so it was very very scary.


The Multi-Host Disease Model

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