On 1 May 1873, at the age of 60, Dr David Livingstone died while on an ultimately futile quest to identify the source of the River Nile. The deprivations that Livingstone suffered over the 30 years that span his three great expeditions to Africa are astonishing. His first aim had been to bring Christianity to Africa; he died fighting to end the slave trade.

Early on the morning of 1 May one of his group of faithful African followers found the explorer dead, kneeling beside his bed. It is not clear whether he was in prayer, or trying to find a position to lessen his excruciating intestinal pain and the accompanying rectal bleeding. A few days earlier he had written in his journal, “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.”

For many years Livingstone had suffered from haemorrhoids but he was too embarrassed to have them operated on. They are unlikely to have killed him, though; his intestines, however, would have been a menagerie of parasitic life. He likely suffered from amoebic dysentery, a prolonged and severe infection of the intestines. In this disease, tiny amoebae found in contaminated water colon - ise the gut and blood seeps out from the ulcers they cause. He had every opportunity to become infected. In a graphic account of his desert crossing back in the 1840s, he boasted, “I have drunk water swarming with insects, thick with mud and putrid with rhinoceros urine and buffaloes’ dung, and no stinted drafts of either . . .”

He certainly also had bilharzia, or schistosomiasis, a disease caused by parasitic worms whose larval stages pass between particular species of freshwater snail and human beings. Livingstone could have become infected with schistosomes when he swam in Lake Nyasa (now called Lake Malawi), which he described as “a heavenly place to bathe”.

The waters close to the shoreline teem with schistosome larvae. The larvae can sense the presence of human bathers and they burrow through their skin. They mature in our bloodstream; female and male worms couple and copulate unrelentingly for years. The female lays hundreds of eggs each day. Some of the eggs get back into the water in faeces and urine, but most lodge in the liver, bladder and bowels, causing bleeding in urine and stools.

After his death, near Lake Bangweulu (in present-day Zambia), Livingstone’s African followers removed his inner organs so as to sun-dry his body. They found what they described as a blood clot the size of a fist. Was this an intestinal tumour? A swollen spleen also common in schistosomiasis, is more likely. They wrapped his body in cloth covered in tar before carrying it back, at great peril to themselves, over a thousand miles to Bagamoyo, on the coast of modern-day Tanzania. From there, the body was taken via Zanzibar to England for interment at Westminster Abbey.

Irrespective of the cause, Livingstone’s death initiated a cult. Born into poverty, he self-taught himself to greatness, only to endure profound suffering in the cause of others. “My desire,” he wrote in the 1860s, “is to open a path to this district [Africa] that civilisation, commerce and Christianity might find their way there.”

This, he hoped, was the surest way to defeat the trade in human beings. It was a narrative that appealed to both the charitable and the materialistic sides of the Victorian psyche. By the 1880s, well-meaning missionaries were pouring in to Africa, but so were mercantile-imperialists. Livingstone would have been horrified, had he lived, to witness the grotesque “Scramble for Africa” that began in earnest a little more than a decade after his death.

David Livingstone was born on 19 March 1813. He grew up in Blantyre, on the banks of the Clyde, near Glasgow. From the age of ten he rose for a six o’clock start, labouring in the cotton mill for 14 hours before spending two hours at school, and then would often read until midnight. Science, above all, fired his imagination. Scotland’s enlightened higher education system allowed him to secure a medical training at Anderson’s College, Glasgow, starting in 1836. He persuaded his father, Neil, that science could be reconciled with religion by tending to the world’s needy and, with his support, joined the London Missionary Society. His future father-in-law, Robert Moffat, an overseas missionary, persuaded him that Africa was where he could most readily spread the gospel.

In December 1840 he left for the Cape. Arriving the following March, he travelled northwards in search of people to convert, settling first at the mission station established by Moffat at Kuruman, in modern-day Botswana. His tetchy relations with other missionaries precipitated a move further north. He was a poor preacher and it remains debatable whether he converted a single African. In 1844, after a lion attack shattered one of his arms, he returned to Kuruman to recuperate and there Moffat’s eldest daughter, Mary, nursed him back to health. They married in 1845 and set up home in Kolobeng, beside the Kalahari Desert.

After crossing the Kalahari to find Lake Ngami, a discovery for which the Royal Geographical Society in London awarded him its gold medal, Livingstone continued north, exposing his family to extraordinary perils. These hardships, and especially the death of his baby daughter Elizabeth from a bronchial infection in 1850, prompted him to send the family back to Britain.

He carried on alone to Linyanti (also in today’s Botswana). The highlands here would, he believed, offer ideal land for Scotland’s poor to cultivate. He did not advocate the imposition of colonial rule; he thought that a mingling of cultures would bring prosperity to Africa. Hoping to find a route that would allow easy access to the interior, he ventured west to Luanda, on the coast of Angola. However, the high prevalence of malaria, the hostile terrain and the presence of tsetse flies led him to rule out this route.

Tsetse fly bites often lead to the death of domestic animals. Livingstone thought that the bite contained a toxin resembling snake venom. We now know that they transmit parasites called trypanosomes, which proliferate in blood, killing susceptible animals.Other species of trypanosome cause the disease sleeping sickness in human beings, although Livingstone didn’t encounter the human form of trypanosomiasis. From Luanda, he headed back east, “discovering” en route Mosi-oa-tunya (meaning “the smoke that thunders”), the majestic waterfall on the Zambezi River which he named the Victoria Falls. He wrote: “It has never been seen before by European eyes, but scenes so wonderful must have been gazed on by angels in their flight.”

It was Livingstone’s diligence as a phy - sician that enabled him to overcome malaria, the disease that had kept most Europeans out of Africa. His scientific training had taught him the importance of evidence-based medicine, so he listened attentively to local witchdoctors, carefully documented the plants they used and assessed their activity. Having read how quinine, a chemical extracted from Peruvian cinchona tree bark, could treat fevers, he began to use it systematically.

We now know that malaria is caused by tiny parasites that enter the blood through bites by infected Anopheles mosquitoes. After maturing in the liver, the parasites enter the red blood cells, where they replicate, erupting every two to three days to cause appallingly high fevers. Quinine causes the parasites to poison themselves by preventing them from detoxifying chemical breakdown products of the red cells they destroy. Livingstone believed that frequent bowel movements would clear the deposits of malaria-destroyed cells, so he added purgatives such as jalop, calomel and rhubarb to his quinine. The formula he hit on by mixing these components was eventually marketed by Burroughs, Wellcome & Co as “Livingstone Rousers”. The application of quinine, in Indian tonic water, for instance, later became a staple for many people inhabiting malarious regions.

Though Livingstone recorded in his notebooks how the presence of mosquitoes was usually predictive of malaria, he subscribed to the then common theory that the disease was caused by inhaling poisonous vapours found in the air over swamps (mal’aria is Italian for “bad air”). Only in 1880, seven years after Livingstone died, did a French scientist, Alphonse Laveran, identify the parasites that cause malaria in a stained smear of infected blood. In 1897 Sir Ronald Ross forged the crucial link between the disease and swampland when he discovered Laveran’s parasites inside swamp-breeding mosquitoes.

For this discovery, Ross became the first Briton to be awarded a Nobel prize, although it was a distant relative of Livingstone’s, Sir Patrick Manson, who had put Ross on to the idea. Manson had shown in 1877 that mosquitoes transmit the tiny filarial worms that cause elephantiasis, a grotesque disease in which the worms wriggle around under the skin. They cause profound itching, but worse, if they enter the lymphatic system, they can stimulate huge swelling of the legs and, most distressingly, the scrotum. Livingstone recorded several cases of elephantiasis. He remarked that the curious habit of geo - phagy – eating earth – was common among certain tribes. A craving to eat earth is thought to result from an innate desire to replenish the minerals and iron lost through internal bleeding caused by hookworm infections, in which minute bloodsucking worms drain the blood from intestinal vessels.

In 1856, Livingstone returned to Britain after nearly 16 years in Africa. Feted as a hero, he delivered a series of lectures and attended a reception held in his honour by Queen Victoria. He published his journals as Missionary Travels and Researches in South Africa. The book was an immediate success and brought him wealth, fame and influence. He formulated the theory that the slave trade would wilt if legitimate trade in commercial goods was established.

For his second expedition to develop such trade, Livingstone raised government funds. Other great explorers of the time, such as Richard Burton, John Hanning Speke, Sam - uel Baker and James Grant, had also turned their attention to Africa. Finding the source of the Nile became the Holy Grail of these Victorian adventurers.

The second expedition set out in March 1858. Its goal was to open up the Zambezi River and turn it into “God’s highway to the interior”. However, the Kebrabasa Rapids, which Livingstone had bypassed on his earlier journey, proved to be impassable to the European steamboats that he thought would bring people there. He turned north, taking small parties on forays up the Shire River, eventually reaching Lake Nyasa. The Shire highlands, he hoped, might prove to be the new utopia he had otherwise failed to reach.

Livingstone’s evangelising call to convert Africa to Christianity was answered by missionaries who, haplessly unaware of the dangers they would face, brought their families with them. One by one, they succumbed to malaria. In 1862, Mary Livingstone, desperately missing her husband, joined the expedition. She, too, died from malaria, unable because of vomiting to keep down any of the quinine given to her. Relations between the European members of the expedition reached breaking point. Eventually they all left.

The obdurate tenacity that enabled Livingstone to overcome hardship in pursuit of his goals also made him extremely difficult to work with. Even Dr John Kirk, whose diplomatic skills made him Livingstone’s righthand man on the 1858 expedition and later enabled him to outwit the Sultan of Zanzibar and bring the African slave trade to an end, had enough. “The infatuation which blinds him, I cannot comprehend,” Kirk wrote in his journal. “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.”

Yet Livingstone, speaking at the University of Glasgow in 1858 before he set out for the Zambezi, had made it clear that his objective wasn’t simple geographical discovery but “a much higher one”. He told the Glasgow students: “It cannot be the design of providence that the horrid system of slavery should exist for ever, or that we should be supporters of that system. And yet we are, though unwillingly, the chief supporters of slavery. Now let mercantile men, ministers and all work together, so as even tually to eradicate that foul blot from the European name.” Livingstone saw the glory of exploration as the means to give him the influence needed to end the slave trade.

The failings of the expedition prompted the Times to publish a diatribe against Livingstone. Questions were asked in parliament and the expedition was recalled. And yet, after his death, missionaries and entrepreneurs began to settle beside Lake Nyasa and in the Shire highlands.

The interest in empire grew. Speke and Bur - ton were foremost among the explorers who followed Livingstone into Africa. They fell into a dispute about the source of the Nile so bitter that, in 1864, Livingstone agreed to chair a debate between them. (The contest never happened, as Speke killed himself in a bizarre shooting accident the day before it was due to occur.) Why was the source of the Nile of such interest to the Victorians? Biblical connotations gave the river great significance to a nation increasingly assured that it was home to God’s chosen people, as Tim Jeal explains in his brilliant book Explorers of the Nile (2011). Moreover, even if only partly navigable, it offered a direct route from the Mediterranean to Central Africa, another of “God’s highways”.

Livingstone had read the ideas of Ptolemy, the ancient Alexandrian historian who had first suggested that the Nile rose from fountains deep in the heart of Africa, further south than Lakes Victoria and Tanganyika. The source of the river, Livingstone believed, lay hidden somewhere in the thousands of square miles of swampland south and east of Lake Tanganyika. Lake Bangweulu, which leads to Lake Mweru and further on to the northward-flowing Lualaba River, was his best guess.

We now know that tributaries feeding Lake Victoria from the Rwenzori mountain range are the true source of the Nile, but Livingstone was investigating the Congo’s headwaters. In 1866, with meagre resources and a relatively small group of African companions, he set off into the interior for the last time. He tramped across the continent’s central watersheds for seven years, looking for connections between lakes. With his scientific instruments broken, much of the time was spent lost in sodden wastelands.

In October 1871 he arrived, deeply sick, at Ujiji on the eastern shore of Lake Tanganyika, expecting to find supplies. They had been plundered. He seemed certain to die until Henry Morton Stanley found the ailing doctor after interviewing local villagers.

Born John Rowlands in Denbigh, north Wales, Stanley was raised in a workhouse and made his way to New Orleans at the age of 18. In America, he changed his name and launched a career devoted to sensational journalism. Who better for the New York Herald to despatch to Africa to “find Dr Livingstone”, whose disappearance had become an international cause célèbre?

Stanley stayed with Livingstone for several months and helped nurse him back to much better health. The two men explored Lake Tanganyika together and agreed that it was not the source of the Nile. Stanley returned and won worldwide acclaim, but Livingstone set off back into the swamps, his mission unfinished.

Many have questioned his sanity at this time, and his notes are candid:

Ideas flow through the mind with great rapidity and vividness, in groups of twos and threes. If I look at a piece of wood, the bark seems covered with figures and faces of men, and they remain, though I look away and turn to the same spot again. I saw myself dead on the way to Ujiji, and all the letters I expect there useless.

In his 1978 biography, David Livingstone: the Dark Interior, Oliver Ransford describes how the missionary must have appeared to those who met him in those final months: “. . . many Africans 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.”

Depressed, lonely, lost and losing blood to the point where he could no longer walk, Livingstone was laid by his African companions in a makeshift hut in Chief Chitambo’s village in Ilala, in the swamps south of Lake Bangweulu. Here, he died. Like the redeemer who was his master, his death defined him.

The revisionist biographies of Livingstone in the post-colonial era were inevitable ripostes to the earlier hagiographies. Certainly he was flawed and obsessive. And yet, because of his iron will, his extraordinary powers of endurance, his gifts as a writer and his medical interventions, not least the use of quinine, Livingstone made a difference. His reports on the slave trade spurred the British public and galvanised political opinion to the point where the Royal Navy intervened to enforce a ban on the passage of slaves across the Indian Ocean.

His unyielding Christianity led him to reject the theories of his contemporary and fellow explorer Charles Darwin. Their contributions to cataloguing the natural world were, however, comparable. Livingstone’s published accounts of nature’s wondrous diversity were received with the kind of awe that David Attenborough inspires today.

It is not his fault that many who came after him had little regard for the people of the continent they tried to colonise. Dr Richard Le Page, a life fellow at Gonville and Caius College in Cambridge, who first taught me about tropical disease and once kindly gave me a first edition of Livingstone’s Missionary Travels, recently told me of his own childhood growing up in Northern Rhodesia, now Zambia. Livingstone was a huge figure there, an inspiration. Le Page’s family and their friends fought against the tsetse fly; they extended the electricity network out into the bush and they built hospitals and schools.

Yes, they were making a living but they weren’t there to exploit anything or anyone. They wanted to help and they were embedded in, not segregated from, the local people. Stephen Taylor, in his book Livingstone’s Tribe (2000), characterises the great man’s followers as those white settlers who sincerely loved Africa. It was this notion of integrating people who could bring sustainable development to Africa that was Livingstone’s dream, a far cry from the cruelties of so many white European colonialists.

He learned to speak the languages of those among whom he tried to spread the gospel. He wished to treat Africans with respect; he tested their medicines and embraced many of their customs. He gave his life in the fight against the slave trade. Few European place names were preserved in post-colonial Africa but it is still possible to visit the towns of Livingstone in Zambia and Blantyre in Malawi.

When Kenneth Kaunda, the former president of Zambia, described David Livingstone as the first African freedom fighter, he might just have had a point.

Michael Barrett is a professor of biochemical parasitology at the University of Glasgow. The university will be holding a week of events to celebrate Livingstone’s bicentenary, including a free medical symposium on 25 February. For further details visit: gla.ac.uk/researchinstitutes/iii/wtcmp/ davidlivingstonesymposium