By the time that David Livingstone died on the banks of Lake Bangweulu, his name was already legend — first, as a great explorer, becoming the first European to lay eyes on Victoria Falls and Lake Malawi, and second as a fierce advocate against the slave trade. But we often forget that he was a medical doctor, and made significant contributions to the nascent field of tropical medicine. In Episode 18 of Bedside Rounds, I recount his innovations in fighting malaria and discuss all the fun (by which I mean quite gross, and very deadly) tropical diseases that he described in his journals. Even though the phrase was almost certainly made up, you should still listen to “Dr. Livingstone, I presume?”
Sources
- Barrett MP et al, Inside Doctor Livingstone: a Scottish icon’s encounter with tropical disease, Parasitology. 2016 Dec 8:1-11.
- Livingstone Online, www.livingstoneonline.org
Music
- All music thanks to Kevin MacLeod of Incompetech.com
- Tracks include: Hidden Past, Deadly Roulette, DarxieLand, Serpentine Track, BrandenBurg No4, Path of the Goblin King, and Overworld
Transcript
Hi, this is Adam Rodman, and you’re listening to Bedside Rounds, a tiny podcast about fascinating stories in clinical medicine. This episode is called “Dr. Livingstone, I presume?” If you’re listening to this on the day the episode is released, then I am on an airplane flying to beautiful Botswana in Southern Africa to work for a six-month stint at Scottish Livingstone Hospital. The hospital is unsurprisingly named for the Scottish explorer, missionary, and physician David Livingstone, who was the first Westerner to see Victoria Falls and Lake Malawi, but also a vehement foe of human slavery, though these days probably most famous for the apocryphal phrase that names this episode. The hagiography that surrounds Livingstone usually focuses on his exploration first, and his fight against slavery second, so it’s easy to forget that Livingstone was a physician, and made important medical discoveries, and popularized a treatment of malaria that we essentially still use today, 150 years later. In this episode, we will explore the life of Dr. Livingstone, and how it intersects with his medical discoveries.
So naturally, let’s start this story at the end, with his death. It is 1873 in the Bangweulu Swamps in the area that is now northern Zambia. It means where the water meets the sky in the local language Bembu, and it’s easy to understand why — even today, local fisherman roam in fiberglass canoes, as the dense swamp immobilizes motor boats. Livingstone is an old man, 60 yet aged beyond his years, leading a handfull of his native employees, traipsing through the swamp, taking notes and looking for the fabled headwaters of the Nile. One Livingstone biographer noted how odd he must have looked to local people, stating:
‘[They] became familiar with the haggard, bearded, benign, ageing man who was often hungry and sick, and yet for some incomprehensible reason wandered from one village to another, halting only to rest and ask innumerable questions or speak of a mysterious redeemer who was his master’.
Livingstone continued to write in his journal up until the day of his death, giving us tantalizing clues about his last days. He noted that he was “reduced to a skeleton,” and was bleeding constantly, writing:
“I am pale, bloodless and weak from bleeding profusely ever since 31st March last. An artery gives off a permanent stream and takes away my strength.”
He strength sapped, unable to walk, his employees carried him to Chief Chitambo’s village on the edge of the swamp. On the morning on May 1st, his companions found him dead, kneeling at the side of his bed as if in prayer.
Livingstone died like he lived. He was obstinate to the end. A year prior, the American journalist Henry Morton Stanley had found him on the edge of the lake, uttering the famous quote that makes up the title of this episode — which was almost certainly made up, by the way — but after being nursed back to health he refused to return home, insisting to continue on his quest to find in the headwaters of the Nile. Such a quest seems odd to us today, but Livingstone hoped that the international and religious cachet of this discovery would help him end the slave trade once and for all. And he most likely died from the diseases that he helped describe and combat. Livingstone had been in tropical regions of the world for decades prior to his death, and his body was certainly a living petri dish of parasites and microorganisms. We know this, because he bragged about it in his first book, writing, ”I have drunk water swarming with insects, thick with mud and putrid with rhinoceros urine and buffaloes’ dung.” Given the incidence of the disease, he almost certainly had amebic dysentery, a cause of chronic, bloody diarrhea caused by tiny parasites called Entameoba histolytica that invade the bowel wall. He also likely had schistosomiasis, caused by parasitic worms spread by snails. These can invade vessels of the body, especially in the liver, leading to similar symptoms as organ failure. In fact, when his companions removed his organs in order to preserve his body, they noted a “blood clot as large as a fist,” which very well could have described a swollen spleen, consistent with schistosomiasis. Both these diseases, as well as his known hemorrhoids, would have contributed to the blood loss that ultimately killed him. And that’s not even including the multiple bouts of malaria that would have sapped his strength.
In any event, his companions, Chuma, Suza Mniasere and Vchopere removed his organs in order to sun-dry his body, burying his heart under a Mpundu tree in the village, where a memorial now stands. They then covered his body with a tar cloth and transported it over a thousand miles to the coast, a journey that must have been fraught with danger. There his corpse was shipped back to the United Kingdom, where a physician friend confirmed his identity by examining an old injury on his left arm from a lion attack. The explorer was then buried in state at Westminster Abbey, his burial stone a final exhortation against the slave trade.
Livingstone’s most lasting contribution in medicine was probably the treatment of malaria. Malaria has one of those awesome pre-modern names that has been reconfigured for modern use, like “dyscrasia” or “sepsis”. It literally means “bad air” in Italian, and reflects that idea that putrid air around swamps caused the disease. We have accurate descriptions dating all the way back to Hippocrates who described “quotidian fever,” and the ancient Romans, who realized that by draining swamps that could decrease incidence of the disease. In fact — and this is one of my Roman Empire fun facts — Julius Caesar even planned to drain the Pontine Marshes outside of Rome as a plan to reduce disease. His assassination unfortunately side-tracked these plans — for another two thousand years, until Caesar-fan Benito Mussolini finished Caesar’s work.
These days, we know that malaria is caused by a parasite of the plasmodium species, which lives part of its life cycle lives in a mosquito, and as another part lives in humans red blood cells. These parasites mature every 48- or 72-hours, the destruction of the red cells causing the cyclical fever. Of course, Livingstone had no idea about this. Germ theory was in its very infancy at the time of his death and it would be another decade until malaria parasites were discovered, and another 20 until his distant relative Sir Ronald Ross proved the mosquito link, work for which he won the Nobel Prize. Livingstone, who rose from poverty to attend medical school at Anderson’s College in Glasgow, was taught the common 19th century Galenic view that “fever” was a disease in-and-of itself, instead of a symptom of a variety of different conditions. And his curriculum had certainly taught about the deadly “African fever,” which had plagued previous missionaries and explorers. From his studies in “materia medica”, which we’d now call pharmacology, he was keenly aware of one of the most potent medications to treat malaria, which he would later popularize and help spread around the world — quinine.
My listeners who are gin drinkers — and as an inveterate whiskey drinker, I forgive you — have certainly tasted quinine; it’s the chemical that gives tonic water its distinctive bitter flavor. And with good reason; British troops stationed in India took it to ward off malaria, and discovered that adding gin made the noxious cocktail and little more palatable. And keep in mind, the quinine concentration in your nineteenth century G+T was much stronger than what we drink for fun now. When he was a youth working in the cotton mill, Livingstone pored over texts describing the medicinal plants of his native Scotland, so it’s no surprise that once he landed in Africa, he diligently took notes on the traditional plants used by medicine men. So it’s very likely he would have been aware of the genesis of quinine. The chemical was originally purified from the bark of the Cinchona tree, which the Quechua people of modern-day South America used to make a tea that was a remedy for the fevers from malaria. Jesuit missionaries in the 17th century brought it back to the Western world, and by the 19th century, this “Peruvian bark” was being cultivated in plantations around the world.
In any event, Livingstone stocked up on quinine before setting sail to the Cape Colony, and then heading north on foot into modern-day Botswana with an intent to spread the gospel. He fell sick from malaria over and over again; we know from his detailed journals from his second expedition that he likely had malaria an astonishing 27 times. I should note here that Livingstone was apparently a poor missionary, acquiring only one convert, Sechele, who Livingstone later accused of abandoning Christianity. Fun fact — Sechele’s village is now Molepolole, in Botswana, where I’m moving in a week. But back to the story, with so much endemic malaria, he made detailed observations in his journals of the symptoms and periodicity of the disease, and performed experiments on dosing quinine in himself and his compatriots. He identified the link between mosquitoes and the disease, for example, but still subscribed to the 19th century idea that it was in fact noxious odours from the swamps that caused the disease. He set about developing a concoction of quinine, rhubarb, jalap, and calomel, which would cause diarrhea and expel these toxins. Through careful experimentation, he discovered that the optimal dosage to treat malaria: take the pill until your ears ring. He called this medication a “rouser”, and after he returned from his first expedition back to Britain, his concoction was patented and sold under the brandname “Livingstone Rousers”.
His use of quinine was so important that it literally meant life-or-death for himself, his compatriots, and devastatingly his family. He returned to Britain a hero who had “discovered” Victoria Falls and Lake Malawi. Thousands of missionaries poured into Southern Africa, hoping to follow in his footsteps. Ignorant of the importance of quinine, many died of malaria. Several years later, his wife Mary also succumbed to the disease when she was so nauseous that she unable to keep her quinine down. On his solitary third and final journey, with his quinine supply pilfered, he was on the brink of death from malaria when Stanley appeared, bringing with him his emergency quinine supply.
His observations about quinine, his experiments in dosing, and ultimately his own fame and faith in the treatment ensured the widespread adoption of quinine to treat malaria, and likely saved thousands of lives. In fact, Livingstone Rousers were sold until the 1920s, and quinine derivatives are still used to treat malaria today.
After 15 years in Southern Africa, Livingstone returned to the United Kingdom with the excitement and reverence comparable to modern-day astronauts. He easily gained financial support for a second expedition, this one scientific in nature, but also tasked with discovering a water route through the Zambezi River which would allow for British settlement of the African interior. At the time, the expedition was considered an abject failure. Malaria devastated the troop, including killing Livingstone’s wife, Mary. And Livingstone was a difficult and demanding boss, who would fire his followers for perceived laziness. John Kirk, the expedition doctor, noted that:
‘It seems madness and to follow a man running such risks for the empty glory of geographical discovery is more than I would consent to … I can come to no other conclusion than that Dr L is out of his mind’.
Livingstone was eventually recalled back to Britain in disgrace, after his entire team left him. However, as modern biographers have noted, the expedition was a boon for science, leading to over 100 published scientific papers. While Livingstone did not realize the tie between the mosquito and malaria, he was the first physician to realize the links between the tampan tick and relapsing fever in humans, in what might be the first documented case of an insect bite causing disease in humans. Livingstone noted how he had observed a cyclical fever develop after bite from the Tampan tick, and noting this, he kept the men of his expedition out areas where the ticks lived on their journey. It would be another 50 years until yet another Scottish physician confirmed that the parasite that the tick transmits was of the borrelia species, the same as Lyme disease.
On the same expedition, he also realized that the tsetse fly transmits the disease — in fact, he attached so much importance to the insect he put in on the cover of his second book. These days, we know the tsetse fly causes African sleeping sickness, but in Livingstone’s time the disease was virtually unknown in Southern Africa. It wasn’t until colonialism forced locals into areas they have previously avoided that it became epidemic. But he noted that the tsetse fly caused disease in livestock, writing,
“Its peculiar buzz when once heard can never be forgotten by the traveler whose means of locomotion are domestic animals; for it is well known that the bite of this poisonous insect is certain death to the ox, horse, and dog”.
While Livingstone assumed the tsetse fly killed with poison, we now know that the disease is caused by parasites called trypanasomes.This tricky parasite can fool the immune system by a process called antigenic variation, making it difficult to become immune. Though Livingstone had no way of knowing this, he noted it in his detailed observations, writing:
‘Inoculation does not insure immunity, as animals which have been slightly bitten in one year may perish by a greater number of bites in the next’.
Both of these observations predated the development of germ theory of disease, but Livingstone’s careful observations helped lay the ground for the development of the field which would soon be called tropical medicine.
As I mentioned earlier, Livingstone had returned to Britain in disgrace, but he did not stay long. Colonization of Africa had begun in earnest, and he had become increasingly distressed by the slave trade. He was convinced that by discovering the headwaters of the Nile River, he would gain the authority to end the slave trade, and hopefully open up an avenue for the poor of Britain to colonize the African interior, living side-by-side with the locals, much as he had hoped the Zambezi might offer. After raising money himself, he set off in 1866 for his third and final expedition, eschewing any European help and relying on his African companions. It was a disaster from the start; he arrived to find his scientific and medical supplies pilfered, he was often sick, and he had to rely on the help of the slavers he despised. He wandered for seven years in the wetlands around the source of the Congo River, and it is here that Stanley found him, and here that he would die in 1871.
Every successive age has reinterpreted the legacy of David Livingstone — a Christian warrior for the British Empire, an advocate for the “partnership of races” during while that empire crumbled, and or an icon to be deconstructed in a post-colonial world. I’m less sure what to make of his medical contributions. Ultimately, Livingstone was hampered by the medical conventions of his time — had his journeys happened a few decades later, perhaps he would have been crowned “the Father of Tropical Medicine”. But what I find so remarkable is that despite abiding by Victorian conventions of infectious disease, he was such a detailed observer and experimentalist to accurately describe insects as vectors of disease, and through trial and error to develop an effective treatment for malaria. Science is built by standing on the shoulders of giants, and when Koch and Pasteur finally ushered in the revolution of germ theory, they could certainly thank David Livingstone for helping prop them up.
That’s it for the show. But don’t stop listening now! Because now I have an exciting new feature, and because I’m terrible at naming things, I’ll just go ahead and call it #AdamAnswers, where I answer fascinating — or trivial — questions about medicine from my listeners. For our inaugural #AdamAnswers, Patrick O’Connor asks via Twitter, “How was the iconic doctor’s bag designed or where does it originate from?” So according to an article in the Scandinavian Journal of Primary Health Care, like basically everything else in medicine, they date to at least the time of Hippocrates. In his treatise “On Good Manners,” he writes:
“[You need to] have the tools, the equipment, the metallics and the rest of it (gauzes, compresses, bandages, drugs) already prepared. Because the shortage of these things creates embarrassment and causes harm. For your trips, you will carry a simple and portable kit. The most appropriate is the one which follows a methodic layout, because the physician cannot keep everything in mind.”
Said doctors bags have been seen in hieroglyphics from Ptolemeic Egypt, and found in Palestinian shipwrecks from the same period. So just remember, the next time you see an iconic doctor’s bag, know that said doctor is participating in an attempt to avoid embarrassment that goes back 2500 years.
Do you have a burning question that you need answered on #AdamAnswers? Do you have a better name for this segment? Probably not, because #AdamAnswers is awesome, but I’d still like to see you try. Then Tweet me at @AdamRodmanMD
Now that’s REALLY it for the show. Like I said, I’m probably either on an airplane now, or already in Botswana. But that doesn’t mean the Bedside Rounds is going anywhere! New episodes are still in the works, and I have some exciting stuff coming. In the meantime, you can listen to all the episodes on the website, www.bedside-rounds.org, or on iTunes, Stitcher, Google Music, or wherever fine podcasts are found. And of course, tell me what you think! I’m on Twitter @AdamRodmanMD, on facebook at /BedsideRounds, and I’ll never turn down a rating on iTunes.
Sources are on the website, but I’m especially grateful to Dr. Barrett’s piece in Parasitology called Inside Dr. Livingstone, and to LivingstoneOnline, an amazing compendium of primary sources from Dr. Livingstone’s life.
And finally, as always, while I am actually a doctor and I don’t just play one on the internet, this podcast is intended to be purely for entertainment and informational purposes, and should not be construed as medical advice. If you have any medical concerns, please see your primary care provider.