The ability to correctly diagnose Ebola was critical in controlling the West African epidemic. As the World Health Organisation declares the epidemic finally over, we find out what it was like setting up diagnostics on the ground. 

Kristian Andersen

Kristian Andersen

The Ebola epidemic of the past couple of years has been the most widespread of its kind in history. While the majority of us saw events unfold through general news coverage, those working on related infectious diseases saw it as their duty to help. Kristian Andersen, and his colleagues, wasted no time in heading out to West Africa to help ensure that labs over there were able to correctly diagnose patients.

 

FLG: Your earlier studies in Lassa fever showed evidence that endemic diseases may actually drive human natural selection, could you give us a brief overview of how that works?

KA: Yeah, so for example, something like malaria is very prevalent and people get infected with it all the time and unfortunately many people will then die from the infection. You can imagine that people that would be resistant to either the infection or the disease might have better survival just because they don’t actually die from the infection. And then over many generations you have genetic variants that might protect you from the disease that will rise in prevalence. That’s what we have seen for malaria. There are many resistance alleles on the African continent that will make people resistant to malaria. And that’s exactly the same that we see with Lassa. We think that this is because Lassa is a very old disease potentially having caused infections in the area, and caused a lot of devastation. Then there are people there who are resistant to that disease and to the infection who then have a better survival rate. What happens is that okay, there’s some sort of genetic variant, maybe it has to do with the way that the virus gets into cells and a genetic variant means that the virus can’t get into the cells. So people can’t get infected and therefore, they’re resistant and therefore, they survive better. And then that just drives that selection basically.

FLG: From your perspective and really in terms of the work that you do, what are the technologies that are really exciting you now and the ones that really have developed in exciting ways for you? What kind of questions are they allowing you to ask that maybe you couldn’t before?

KA: The technologies are primarily sequencing. Sequencing has just revolutionised our ability to get a vast amount of sequence data very rapidly. Going forward, there’re two main things that I’m really excited that we can use that for. One is, that we can deploy this during outbreak situations where we can use sequence information to complete the delineate transmission chains to exactly figure out, who infected whom and how is the virus spreading and transmitting during an outbreak. That’s really exciting. Some of the new technologies coming online are even faster than what we have available now and also some of them can be deployed in resource limiting settings like West Africa for example. I think those are going to be really exciting. The other thing is that because sequencing gives us this unbiased view of all the genetic material present in the sample, we can use that for diagnostic purposes. So when you have a sample today, you think maybe the patient is infected with three different pathogens you have to specifically test for those three different pathogens using something like PCR which requires a priori knowledge of which organism might be causing the disease in the patient. With sequencing, we don’t need that a priori knowledge, we can just take and sequence everything and it will give us a completely unbiased view of all the different pathogens that are in there. So I think using sequencing for, you know pathogen detection and surveillance is also going to be a huge thing going forward. So those things, I’m pretty excited about.

 

You can read the rest of our interview with Kristian on page 35 here.

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