Eliminating sleeping sickness

DODI: From the World Health Organization in Geneva to the Savannahs of Western Kenya, a long battle against one of humanity's deadliest parasites has reached an incredible milestone.

GERARDO PRIOTTO: We are advancing quite rapidly in the elimination of this disease.

DODI: Today, Conor, we are talking about how Kenya eliminated human African trypanosomiasis. Also known as Sleeping Sickness as a public health problem. This is a story that brings together science, community, and decades of determination.

CONOR: And this is very close to my heart. I remember sleeping sickness as a child. It was all around us, and that is what matters today on this episode of Discovery Matters.

THEME TUNE

DODI: Joining us to unpack the science behind this recent success is Dr. Gerardo Priotto.

GERARDO PRIOTTO: I am a medical doctor by training, and I also did further training on epidemiology. And then because of my work, I specialize a lot in tropical diseases, and so I am working currently at the WHO in Geneva. That's the headquarters of the WHO, and there's a department in the WHO called Neglected Tropical Diseases.

CONOR: The Department of Neglected Tropical Diseases. I see dusty corridors and filing cabinets. I really want to work there.

DODI: I bet you do. I bet you have a great name. And Dr. Priotto says that there are 21 diseases within that department.

GERARDO PRIOTTO: One of those is the sleeping sickness that we call human African trypanosomiasis. And so, I'm the person in charge of that disease. Within the NTD department in WHO.

CONOR: So, before we get into the sleeping sickness, what is Dr. Priotto's background and how did he end up specializing in tropical diseases?

DODI: His CV is impressive. For many years, he worked with Doctors Without Borders and with epicenters conducting public health research into tropical diseases.

CONOR: So not shying away from the big world problems then?

DODI: No way. Rather, he has tried to tackle them face on and indeed he has always had this kind of mentality.

GERARDO PRIOTTO: After I finished medical school, my objective became to work in something that would contribute to solving the big problems. At that time, I was not thinking of tropical diseases. I was thinking of people suffering from disease of any cause and that I had just acquired a profession and a body of knowledge that would allow me to be helpful. And so, I thought that was better. It was, I don't know, more important for me than just making money and having a nice financial situation. For me, it was more important to, to feel good about what I was doing.

CONOR: Okay, Dodi. So, at the top of the episode, you said that we're gonna get into how sleeping sickness was eliminated in Kenya. But before we talk about elimination, can we just understand the enemy? What exactly is sleeping sickness?

DODI: Basically, it is a parasitic disease transmitted by the bite of the tsetse fly, and without treatment it is fatal.

CONOR: The nasty little tsetse fly.

DODI: Yeah.

CONOR: I remember this one. My granddad was always going on about it and how impactful it was, not just on the people around him, but also his cattle.

DODI: Mm. And it looks like an ordinary house fly. But this particular species lives in Sub-Saharan Africa, feeds on the blood of animals and people to the detriment and frustration of your granddad. And what makes it particularly dangerous is that it carries a microscopic parasite called trypanosome.

GERARDO PRIOTTO: The name sleeping sickness is because this is a parasite, unicellular. It has a flagellum. It's moving all the time. It's a moving little parasite that is in the blood and in the lymph lymphatic system, and at some point, they're looking for the brain. They have an objective, which is reaching the brain, and when they manage to enter the brain, they reproduce there. And they provoke a lot of neurological signs and symptoms, and one of them is a sleep-awake disturbance of this daily cycle that we all have. When we are about to go to sleep, our brain is getting ready to go to sleep, and then, at some point gets ready to wake up. So these parasites, they derange that cycle and so the person infected will be in the middle of a conversation in the middle of the day and fall asleep just like that. Suddenly, totally asleep and maybe during the night will have insomnia. We wake up, the whole cycle is disturbed and that's why in the population they gave that name. There is a sleeping sickness.

DODI: It doesn't stop there. Dr. Priotto says the diseases can also cause deeper problems.

GERARDO PRIOTTO: You have people who are unable to speak, unable to walk, and then they enter into mental confusion. They don't know where they are, total mental confusion, and then they go into coma and then they die.

CONOR: This sounds like something out of a Stephen King novel.

DODI: It's gross to think about, isn't it? I mean, this is a bug that is determined to reach the brain with nothing but destruction in mind, and that makes it easy to see why historically, communities in Africa have been terrified when outbreaks have appeared.

GERARDO PRIOTTO: There is a long history already about this disease, like in the 1930s, 1940s, that was the colonial powers that were in place in Africa. They noted that the large chunks of the population were dying, and you had more than 10,000, more than 50 or 60,000 people per year dying of this disease. It became a big problem even at the economic level. So, they took a lot of measures, but they were like enforced even militarily, and they were isolating all the cases to wait for their death basically because there was no treatment. But they did manage to decrease the transmission that way.

DODI: At this point, communities all across Africa have managed to get some kind of grip on the diseases, but this is also the same time as when more African countries were given their independence.

ARCHIVE: The world has gained a new nation, the Sudan, for 58 years under the joint rule of Britain, and Egypt becomes an independent republic… In the New Africa…One more independent country. The state of Uganda… The Garden party at Government House was an informal farewell to British rule in Kenya.

DODI: And with this came new priorities like forming governments. And so, this terrifying disease took a backseat. It was no longer a high-level problem.

GERARDO PRIOTTO: And then the disease came back with fury. And so, we had, again, in the end of the last century, 1990s, we had again more than 30,000 cases reported per year when the actual number of cases was probably 10 times more than that.

DODI: Dr. Priotto says that even military style control was used to isolate patients, but when the treatments finally arrived, they were often so brutal, perhaps the treatment was worse than the disease.

GERARDO PRIOTTO: We had one treatment that was very toxic. It is still in use for very few cases, but it's a derivative of arsenic. There is a, an arsenic derivative that we are injecting in the veins of people, and that will kill some of the patients. It can go up to 8% of the people treated and the population when they know that used to create a lot of fear of getting that treatment. And they prefer not to get tested and to remain sick.

CONOR: Yeah. A medicine so toxic that people are afraid of it, right? I mean, that sounds really familiar. So chemotherapy, let's poison the cancer until we hope that the cancer dies first rather than the patients. I mean, this is why people are, are so afraid to be treated often. So when did this change in mindset happen? When did the first shifts appear, which would eventually lead to the elimination of the disease?

DODI: As is often the case, it was about education.

GERARDO PRIOTTO: This is a disease that hides, it hides behind other common diseases more common that have more or less the same signs and symptoms, especially at the beginning. So you have basically fever and headache and fatigue, and the patient will have that. And in in a hospital, in a health center, they will suspect other diseases before suspecting this one, and it can hide in that way.

DODI: Dr. Priotto explains that, making sure the health professionals who are treating the diseases understood its very nature of hiding behind other diseases. He made sure that the medical health professionals could diagnose the disease properly. That was priority number one.

CONOR: Education. Education. Education.

DODI: Mm-hmm.

CONOR: Always the best first health intervention. So a huge shift in detecting disease. But that doesn't change the fact that people were terrified to get treated.

DODI: Correct. If the people would not come to the professionals. The professionals, and by this time that included Dr. Priotto himself, had to go to the people.

GERARDO PRIOTTO: Yes, we need to work and we need the collaboration of the community because from all the time we are sending mobile laboratories. So it's mobile units. They go with a car or even with motorbikes to the faraway villages in rural Africa. And there we set up a laboratory for a day or for three days in the local school or under the mango trees. And then we test the whole community from the youngest to the oldest. So we do a blood test by just taking a drop of blood from a finger prick and we have serological tests and test the whole community. And that's how we find the infected people that can be treated. But that requires the community to participate.

CONOR: I love that. I love the idea of mobile labs under mango trees, testing entire communities from the children all the way through to the elders.

DODI: And that is just one part of what Dr. Priotto and others started doing to eliminate the diseases. The other part was making sure that people were aware of the disease.

GERARDO PRIOTTO: So that when there are signs and symptoms that could be this disease that they don't stay at home, but they go to the right health centers to get diagnosed and treated if positive. So by doing that repeatedly every six months, or at least every year in the same villages, then that is how we manage to eliminate the disease. Because the trypanosomes are these parasites.

CONOR: And this kind of thing doesn't just happen in isolation. This public health success is coordinated. It requires lots of different organizations and bodies to work together. Governments, communities, scientists, right?

GERARDO PRIOTTO: Yes, so this is 25 years ago. The producers of all the medicines, that's two companies, there's Sanofi and Bayer. They engaged. They committed to keep pro producing all the drugs necessary to treat all the patients, and all these drugs are donated to us, to WHO, and then we make sure every patient has a treatment worldwide. So that has been working very well.

DODI: And not to blow our own trumpet too much, but at Cytiva we have also supported Dr. Priotto and his work.

GERARDO PRIOTTO: Cytiva came forward and they donated a product that allows us to create one of the best diagnostic means. We call that mini columns. It's a gel that has electrical charges that allows us to filter the blood so we can put a big volume of blood from the patient and it will all get filtered. And the only thing that passes is the trypanosomes, this organism that are still moving there, and then we can see them in the microscope so that those are collaborations of the private sector that are also coming together. So keeping this, this type of collaboration is very important and it decreases that neglect.

CONOR: We've heard about the training. We've heard about the surveillance. We've heard about people coming forward and being less afraid. The community outreach, what happened next?

ARCHIVE NEWS: In a landmark ruling achievement, Kenya has officially received certification for the elimination of human African trypanosomiasis. Commonly known as sleeping sickness.

DODI: In 2025 this year, thanks to everything you just said, education, awareness, outreach. The World Health Organization validated Kenya as having eliminated sleeping sickness as a public health problem. This is huge.

GERARDO PRIOTTO: We felt very good. Because it’s taking note about successes of the work you are doing.

ARCHIVE NEWS: The announcement brought hope and relief to many who have suffered from the disease.

GERARDO PRIOTTO: So that's a public recognition of a success. But I have to say that Kenya in August is not the first country, is country number 10. That receives this validation from us, from WHO. And so we are advancing quite rapidly in the elimination of this disease. And this is, is very impressive. It's getting a lot of recognition, getting a lot of support from other partners. So it's not WHO working all alone. There are other partners, countries that are funding the work and we are advancing all together. Towards the elimination of this disease.

DODI: When WHO validated Kenya's elimination of sleeping sickness. It wasn't just a proud moment. It was the culmination of decades of coordinated effort by Dr. Priotto and others.

CONOR: Kenya then is the 10th country to be validated as sleeping sickness. Free. Part of a much bigger picture here. The global fight against neglected tropical diseases.

DODI: Exactly, and this issue of neglect in the poorest corners of Africa is something that Dr. Priotto sees as a vital to address.

GERARDO PRIOTTO: Because it's a disease of the poor people in rural Africa. And so for many years. There was no commercial stimulus to elaborate new treatments or new diagnostic means, and that's why we call it neglected, but it's also neglected by governments. So some of the very countries that are affected, their governments, they neglect the disease, they invest in other priorities. Because this one affects the poorest and sometimes people who don't even vote in the elections.

CONOR: Sleeping sickness mostly affects the rural, poor people who often don't have political influence or access to healthcare or a voice. But every country that does eliminate it chips away at that neglect and helps communities get stronger and be more successful.

DODI: Right, and there's momentum building. More countries are preparing for validation and WHO expects up to six more by 2026.

GERARDO PRIOTTO: At the personal level, it's a literate and clear right now what is next. Because I am soon going to retire and is not sure how soon I will do it. But even if I retire, I can continue collaborating through consultations and through the different networks. Then about the whole movement that shall continue, and we are documenting everything we do and things are set up in a way that other actors can take over. In my own organization, WHO, there is right now a big downsizing, so there has been cuts of funding. So in my department, about 40% of the staff are leaving because it's been reduced strongly. And it's, at this moment it's very unclear to, to talk about what is next in WHO and to what extent we are going to be able to continue this same effort or at, at this level of effort. And so that, I cannot say, but there is a little uncertainty at the moment. We shall see in the next couple months maybe what is going to be the future, what shape it'll take. Altogether, this shall continue, and there is commitment. I was just last week in Nairobi in a big meeting where there were many expressions of commitment of joy about the successes, but on the way forward, which requires efforts for several more years.

CONOR: He sounds cautiously optimistic, but also a little bit worried.

DODI: Yeah. The hard facts are that funding cuts could make it harder to realize progress in eliminating the sleeping disease from other countries. But as you said, Conor, there is some optimism here from Dr. Priotto as he prepares to retire.

GERARDO PRIOTTO: I do believe that we are going to keep advancing, keep progressing, and we could reach zero cases.

DODI: And Dr. Priotto says that focus could very well be narrowed onto the Rhodesian Sleeping Sickness Disease, a specific version of the disease prevalent in Western and Central Africa, where it accounts for 92% of human African trypanosomiasis cases.

GERARDO PRIOTTO: That one stays with the animals. It's a zoonosis, so that one is hard to eliminate, but we can keep it at very low levels. And we call that elimination as a public health problem. But in, in Central and West Africa, we call it elimination of the transmission, of the disease. In parenthesis, we write zero cases so that in a few years we are likely to get there. So I think that's enough of the stimulus to, to keep, keep the work up because we are getting real, real success in that with this disease.

CONOR: What really stands out to me from today's episode is how sleeping sickness isn't just a medical problem. It's a story about persistence, education, social evolution, and collaboration.

DODI: Yeah, we learned that defeating and neglected tropical disease requires more than medicine. It takes trust, outreach, and commitment from local communities.

CONOR: The disease itself shows us how poverty and geography shape health outcomes. It thrives where access to healthcare and political influence are weakest. We also see how the power of innovation, such as portable labs and improved diagnostics can bring science directly to rural areas where it can have an impact on the ground.

DODI: Directly under the mango trees.

CONOR: Indeed.

DODI: And global partnerships between WHO, Governments and private companies show how coordination can overcome longstanding neglect.

CONOR: The elimination of sleeping sickness in Kenya this year shows us that progress is possible when science meets sustained community engagement.

DODI: I'd say the biggest lesson from today is perhaps that continued vigilance and funding are essential because success stories like this can only last if the world keeps caring. Speaking of lessons, let's say should we go learn something? What? Let's hear about what we've learned?

CONOR: Yeah. What have you learned this year?

DODI: Cus’ every day is a school day.

CONOR: What have you learned this week even?

DODI: I loved this article from Science Daily. It's a little bit weird but fascinating, and this is about how your hair might be the next big thing in dental care.

CONOR: Sorry, explain to me how my hair is gonna be anything…

DODI: Sorry, explain to me how my hair is gonna be anything…

CONOR: Tiny little teethy weeny.

DODI: We'll try this. Yeah, exactly. Researchers at King's College in London found that keratin, of course, that's the protein that you find in hair, skin, and wool can repair tooth enamel. Stopping early decay and even blocking sensitivity. I don't know. These days when I drink something really cold, it hurts my teeth.

CONOR: Mm-hmm.

DODI: So this could be good for me. Right. And it would block sensitivity by forming a mineralized layer that mimics the enamel on our teeth.

CONOR: Mm.

DODI: And that this did better than fluoride in lab tests. And scientists say perhaps it'll make its way into toothpaste or dentist apply gels in two to three years.

CONOR: Fantastic. Well, I've been looking at, obviously my favorite topic is the microbiome, of course, and something super interesting, which has been gaining traction. But there is yet another study that has identified distinct patterns in the gut bacteria of children and adolescents with autism spectrum disorder, ADHD, and anorexia nervosa. All three of these disorders were looked at in something that was published in the Journal Neuroscience, and it shows that altered levels of hormones that regulate your appetite suggest that there's a really complicated interplay between the gut microbes, our eating behaviors, and brain health in these conditions. So yet again, more connection between what's going on in our brains and what's going on in our guts and how they relate to each other. And perhaps we need to stop thinking about the brain and the gut as two separate things…

DODI: But also, that study is the topic of much controversy because I also read an article from another group of scientists who said, hold on. It's a bit too simplified. So I think the very topic is great because scientists are really digging into it and trying to say like, don't take too much for granted there. Perhaps it's involved, but you can't draw too many conclusions. It's a really interesting controversial topic in science these days.

CONOR: And, and good science is controversial, right?

DODI: Yes.

CONOR: There should be arguments about this because it's only through argument and discussion and looking at the data that you can really get to reasonably good conclusions that help advance healthcare.

DODI: Amen.

OUTRO

DODI: If you would like to get in touch with us, please do write to Discovery.matters@cytiva.com. We love the old-fashioned email way of keeping in touch our producer mixer and sound fantastico is Tom Henley. My name is Dodi Axelson.

CONOR: And I'm Conor McKechnie. Make sure you rate us on Spotify or whatever platform you use. It really does help the podcast to reach new people. Thank you for listening to Discovery Matters, brought to you by Cytiva.

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