A Short (Hi)story of Malaria: The Discoveries that Brought Us Here (Part 2)

[This post has been written by Xavier Fernàndez-Busquets and it is the second post on a series of the history of malaria]

In India during the 1870s Patrick Manson linked for the first time a disease with a mosquito vector

Towards the end of the 19th century British colonialism in the tropics was at its highest: young MDs went to the colonies attracted by a salary of 400 ₤/year and a reasonable life pension at the end of the service, plus the flavor of adventure. In India during the 1870s Patrick Manson linked for the first time a disease with a mosquito vector when he managed to dissect mosquitoes allowed to feed on a filariasis-infected person and found the parasitic worms in the body of the insects.

However, Manson was not an entomologist, and he wrote to London asking for books on mosquitoes; the British Museum replied: “There are no books about mosquitoes, but we are sending one on cockroaches with the hope that it will be of use in your investigations.” I bet it was not. Some of Manson’s letters of the time distilled an underlying disappointment: “I live in an out-of-the world place, away from libraries, and out of the run of what is going on. I do not know very well the value of my work, or if it has been done before, or better.” Despite these shortcomings, Manson finally published his results in 1878 and was acknowledged as the father of medical entomology. But his working scheme had an important flaw.

Manson was calamitously misguided regarding his idea of how the parasites re-entered the human host

Although Manson was right in explaining how blood pathogens went from human to insect vector, he was calamitously misguided regarding his idea of how the parasites re-entered the human host. Essentially, he insisted that infected mosquitoes decomposed in the environment and people got infected when ingesting the pathogen e.g. from drinking water. In 1884, with the objective of proving this wrong hypothesis, Manson raises funds and sends to India Ronald Ross, who will be at the center of one of the most fascinating controversies regarding the distribution of credit for unraveling the mechanism of how malaria is transmitted to humans. Right from the start an acrid dispute arose between the British and Italian schools, as it is clearly evident from these words by Manson: “The Frenchies and Italians will pooh pooh it at first, then adopt it, and then claim it as their own.” But in 1896 Giovanni Battista Grassi and Amico Bignami published their hypothesis that the bite of the mosquito transmitted malaria to humans.

Despite being a MD, the interests of Ross were more on the arts than on curing people, and it took some determined insistence from his father to convince him that medicine was to be his main occupation. More often than not, the facts of history appear to belong to different realities depending on who is telling them, but it seems that in this case we can assert without fear of being too misled that Ross was not very good at making friends if we have to judge him by his written opinions: “Please don’t believe too much of Grassi & Cos.’ work, their actual observations have been of the slenderest and... the rest is eked out by aid of my reports,” and “The work on human malaria is only of secondary importance, a mere detail of my work on birds.”

Rossi (not Grassi, not Bignami, not even Manson) got in 1902 the Nobel Prize in Physiology or Medicine

According to authoritative journalistic research, Ross described the malarious Indians he experimented upon as “people who love filth” and “really nearer a monkey than a man.” He also despised the zoologists that might have helped him: “Mere naturalists, fit for nothing but classifications, making pretty pictures & belonging to societies.” Not even insects escaped his wrath since to Ross, mosquitoes were “as obstinate as mules” because they were usually not willing to bite natives, who, by the way, were often deceived into the belief that if they let mosquitoes bite them, the insects would remove the disease from their bodies.

Unluckily for Ross, the abundant correspondence exchanged between him and Manson has been mostly preserved: “Bignami is a pure villain… He wants to secrete a mosquito theory of his own... He wants to bite into the heart of your theory, suck its juices & then bloat & swell into a discoverer  –or rather until he is thought to be one... He is quite capable of spreading his six legs over your work & calling it all his own... if you have not squelched him already you ought to do it.” But Bignami and Grassi had come with the correct hypothesis first, being the pioneers in experimentally infecting a human volunteer with malaria through the bite of a parasitized mosquito, a result published in 1898; and Grassi had fingered Anopheles specifically.

As a last cruel irony, the species of Anopheles named after him –A. rossi– for years was believed not to transmit malaria to humans

Rather unexpectedly, though, Ross (not Grassi, not Bignami, not even Manson) got in 1902 the Nobel Prize in Physiology or Medicine awarded "for his work on malaria, by which he has shown how it enters the organism and thereby has laid the foundation for successful research on this disease and methods of combating it." Incidentally, Laveran obtained the Nobel Prize in Physiology or Medicine in 1907, awarded "in recognition of his work on the role played by protozoa in causing diseases." Ross died in 1932 as a bitter, ruined man: “I had lost money over the work, I had received practically nothing but skepticism or even abuse in return, and most of my results were credited to others.” “The word malaria,” he declared, made him “nearly as sick as the thing itself would have done.” As a last cruel irony, the species of Anopheles named after him –A. rossi– for years was believed not to transmit malaria to humans. When it was finally discovered that it did, it had by then come to be known as A. subpictus, the name bestowed upon it by Grassi.

More information

Read the part 1: A Short (Hi)story of Malaria: From Dinosaurs to a Simple "Bad Air"

Read the part 3: A Short (Hi)story of Malaria: Darkness and Light