Koalas have chlamydia ladies and gentlemen. Koalas have chlamydia. If you knew that already that’s probably
because you saw this article. British pop group One Direction came to Australia, held koalas for a photo opportunity, got urinated on by those koalas and were told by the handler that they
should get themselves checked out because a lot of Australia’s koalas have chlamydia. And that handler wasn’t kidding. In some areas, 80% of koalas have chlamydia. Now, all around Australia, koala populations are in decline. In some cases, these declines are very rapid with populations halving in just five to ten years. That’s fast enough that in our lifetimes, these populations could disappear completely. Experts think that in some areas, especially in Queensland, these declines are actually due to chlamydia and the infertility and increased mortality that it causes. So, what are we going to do about that? Well, the safe sex message has failed. It’s estimated that koalas use condoms just 0% of the time. So what we would really like is a vaccine. Researchers in Queensland are working on just such a vaccine and early trials are showing a lot of promise. But even if we have a fantastic vaccine, it won’t be that easy to get it to koalas. They’re out in the bush, they’re up in trees. Field workers think that they would only be able to vaccinate around 20% of an infected koala population every year and with the population already in decline, is that actually going to be enough? Well, maybe there’s a way to vaccinate smarter, to get more bang for our vaccination buck. Perhaps there are certain koalas that we can target for more effective vaccination strategy. But how do you figure out who they are? You can’t just go out and try vaccinating and see what works. It’s too expensive and it uses time that we do not have. I tried to deal with this problem by making a computer simulation. In this simulation, koalas interact, mate, transmit chlamydia, have joeys and die. Now this simulation is very fast. I can simulate fifty years in just two seconds of real time and what this means is that I can try out tens of thousands of different vaccination strategies to see which ones work the best. So, what did I find out? Well, it looks like the key is vaccinating young female koalas aged between one and two years If we target these koalas, then we can reverse that decline and what’s more, we can do it fast. Perhaps in as little as five years. That’s good news for koalas, that’s good news for Australia, and most importantly of all, that’s good news for my favourite band. Thank you.