Malaria: History and Discovery
Malaria is one of the oldest and deadliest companions of the human species. Hippocrates described its tell-tale periodic fevers more than two thousand years ago; its very name — from the medieval Italian mala aria, “bad air” — preserves the centuries-long, mistaken belief that the foul vapours of swamps caused it. The truth took until the late nineteenth century to uncover: in 1880 the French army surgeon Alphonse Laveran saw the malaria parasite in human blood, and between 1897 and 1900 Ronald Ross in India and Giovanni Battista Grassi in Italy proved that Anopheles mosquitoes carry it. From a South American tree bark to a Chinese herb rediscovered by Tu Youyou, the search for a cure spans every inhabited continent. This page traces that history honestly — what is established, what is disputed, and what was once believed and later overturned.
Table of Contents
- An Ancient Disease: Hippocrates and the Periodic Fevers
- The Name: “Mala Aria” and the Miasma Theory
- Laveran Discovers the Parasite (1880)
- Naming Plasmodium and Mapping the Species
- Ross, Grassi, and the Mosquito (1897–1900)
- Cinchona Bark and Quinine
- Chloroquine, Artemisinin, and Tu Youyou
- Malaria and the Human Genome
- Legacy: From Bad Air to a Global Fight
- Research Papers and References
- Connections
An Ancient Disease: Hippocrates and the Periodic Fevers
Malaria is ancient. Genetic and historical evidence places the disease alongside humanity for tens of thousands of years, and it has plausibly killed more people than any other infectious illness in history. Long before anyone understood its cause, physicians recognised its unmistakable signature: a fever that returns on a fixed schedule. In the fifth and fourth centuries BCE, the Greek physician Hippocrates and his school described these intermittent fevers with remarkable precision, distinguishing the tertian fever — a paroxysm every third day, that is, roughly every 48 hours — from the quartan fever, which recurred every fourth day, about every 72 hours. We now know these rhythms reflect the synchronised cycles in which different Plasmodium species burst out of red blood cells, but the clinical observation came first by more than two millennia.
Hippocrates also linked these fevers to environment and season, noting that they clustered near marshes and stagnant water and worsened in late summer and autumn — an association that was entirely real, even though the mechanism (mosquitoes breeding in still water) would not be understood until the 1890s. Similar descriptions appear in Roman writers such as Celsus, in ancient Chinese and Indian medical texts, and across the classical Mediterranean, where the disease helped shape settlement patterns and, some historians argue, the fortunes of empires. The Hippocratic texts are named here as historical primary sources rather than as modern citations.
The key historical point is that malaria was a recognised, named, feared clinical entity for thousands of years — understood by its fevers, its seasons, and its swampy haunts — while its true cause remained completely hidden. That long gap between accurate observation and correct explanation is the central drama of malaria’s history.
The Name: “Mala Aria” and the Miasma Theory
The word malaria comes from the medieval Italian phrase mala aria, literally “bad air.” It encodes the long-dominant miasma theory of disease — the belief that sickness arose from breathing the noxious, putrid vapours rising off swamps, marshes, and rotting matter. To anyone watching fevers strike people who lived near stagnant water, especially on warm nights, the swamp-air explanation seemed obvious and was held by serious physicians for centuries. The disease was also known in English by older names such as ague, marsh fever, and paludism (from the Latin palus, “marsh”).
The Italian term was associated with the physician Francesco Torti (1658–1741), and the word entered English usage in the eighteenth century: the Oxford English Dictionary records the writer Horace Walpole using “malaria” in a 1740 letter describing “a horrid thing called the mal’aria, that comes to Rome every summer and kills one.” For a long time the word named the supposed poisonous air itself rather than the disease; only later did it settle into the name of the illness we know today.
It is worth being clear that the miasma theory was wrong about the mechanism but not entirely wrong about the pattern: the “bad air” of swamps really did mark dangerous places, because those swamps were breeding grounds for the Anopheles mosquitoes that actually transmit the parasite. The name malaria is therefore a fossil of a discarded idea — a four-hundred-year-old guess, preserved in a word, that pointed at the right places for entirely the wrong reason.
Laveran Discovers the Parasite (1880)
The decisive break came in 1880. Charles Louis Alphonse Laveran (1845–1922), a French army surgeon stationed at the military hospital in Constantine, Algeria, was examining fresh, unstained blood from soldiers ill with malaria under his microscope. On 6 November 1880, in the blood of a feverish patient, he watched something no one had described before: within and beside the red blood cells were pigmented bodies, and in one of them slender filaments were lashing and moving. Those moving filaments — the exflagellating male gametes of the parasite — convinced Laveran that he was looking at a living animal parasite, not a bacterium and not a product of the blood itself. He had discovered the cause of malaria.
Laveran’s claim met years of scepticism. Many leading researchers expected the cause of every major disease to be a bacterium — this was the triumphant era of Pasteur and Koch — and a one-celled animal parasite living inside red blood cells was an unfamiliar idea. It took the better part of a decade, and confirmation by Italian investigators using improved staining methods, before Laveran’s discovery was widely accepted. He was eventually vindicated and, for this work and his broader research on protozoan diseases, awarded the Nobel Prize in Physiology or Medicine in 1907.
Laveran’s 1880 observation is the hinge of the entire story. It moved malaria from the realm of “bad air” into the realm of a specific, visible, identifiable organism — and it raised the obvious next question that would occupy the following two decades: if a parasite causes malaria, how does it get from one person into another?
Naming Plasmodium and Mapping the Species
Laveran himself initially gave the new parasite the name Oscillaria malariae, after the oscillating filaments he had seen. The name that stuck, however, came from Italy. In 1885, the Italian investigators Ettore Marchiafava and Angelo Celli re-examined the organism and placed it in a new genus, Plasmodium — the name still in universal use today. (The genus name was borrowed from a slime-mould term and is not biologically apt, but by the rules of scientific naming it has priority and remains official.)
Over the following years, Italian and other researchers worked out that malaria is not one parasite but several, each producing a slightly different illness and fever rhythm. The species that infect humans were eventually catalogued as Plasmodium falciparum (the most dangerous, responsible for the great majority of severe and fatal cases), Plasmodium vivax and Plasmodium ovale (which cause relapsing tertian malaria and can lie dormant in the liver), Plasmodium malariae (the classic quartan fever), and, recognised much more recently as a significant human pathogen, the monkey parasite Plasmodium knowlesi in parts of Southeast Asia. Matching each parasite to its characteristic fever finally explained, in cellular terms, the tertian and quartan patterns Hippocrates had described.
This species map mattered enormously for treatment and control, because the parasites differ in geography, severity, drug response, and their ability to relapse. Identifying which Plasmodium a patient carries remains, to this day, a central question in diagnosing and treating malaria.
Ross, Grassi, and the Mosquito (1897–1900)
Knowing the parasite existed was not the same as knowing how it spread. The crucial idea — that biting mosquitoes carry malaria — was proposed as a hypothesis by the British physician Patrick Manson, who had earlier shown that mosquitoes transmit another parasite (the worm causing filariasis) and who mentored a younger army doctor in India to test the theory. That younger doctor was Ronald Ross (1857–1932). Working in India under often discouraging conditions, Ross painstakingly dissected mosquitoes that had fed on malaria patients and, in 1897, found malarial parasites developing in the stomach wall of a particular type of mosquito (which we now class as Anopheles). The following year, using bird malaria as a model, he traced the parasite all the way to the mosquito’s salivary glands — demonstrating how the bite delivers infection. For proving the mosquito transmission of malaria, Ross received the Nobel Prize in Physiology or Medicine in 1902, becoming the first British Nobel laureate and the first born outside Europe.
At the very same time, in Italy, the zoologist Giovanni Battista Grassi (1854–1925) and his colleagues Amico Bignami and Giuseppe Bastianelli were working out the cycle in human malaria. Between 1898 and 1900 they identified Anopheles mosquitoes specifically as the human vectors, described the parasite’s full development in the mosquito, and confirmed the cycle experimentally — including the dramatic demonstration that people deliberately exposed to Anopheles bites in a malarious district could be protected by mosquito netting. Grassi’s work nailed down the human side of the story that Ross had opened with birds.
The relative credit became one of the most bitter priority disputes in the history of medicine. Ross, supported by Manson, accused Grassi of fraud and minimised the Italians’ contribution; the Nobel committee considered a shared award before giving the 1902 prize to Ross alone, partly on the advice of Robert Koch. Most historians today regard this as genuinely shared discovery: Ross first showed a mosquito could carry the malaria parasite and trace its path to the salivary glands, while Grassi and his colleagues established the precise Anopheles-to-human cycle. Honesty about this history means crediting both lines of work, not just the one that won the medal.
Cinchona Bark and Quinine
Long before anyone understood what caused malaria, an effective treatment had already crossed the Atlantic. The bark of the South American cinchona tree (genus Cinchona, native to the Andes) was used to treat fevers, and from the seventeenth century it was carried to Europe — famously associated with Jesuit missionaries, which is why it was long called “Jesuit’s bark” — where it became the standard remedy for the ague. It genuinely worked, and for two centuries it was one of the few specific drug treatments in all of medicine that reliably did what it claimed.
In 1820 the French chemists Pierre-Joseph Pelletier and Joseph Bienaimé Caventou isolated the active alkaloid from cinchona bark and named it quinine. Purified quinine allowed accurate dosing and made the treatment far more reliable than chewing or brewing raw bark, and it became a strategic commodity: access to quinine shaped colonial expansion, military campaigns, and the movement of people into malarious regions throughout the nineteenth century. Demand was so great that cinchona was eventually cultivated on plantations far from its Andean home.
Quinine remains in use today, particularly for severe malaria and in places where newer drugs are unavailable, though it has largely been superseded by better-tolerated medicines. It stands as a striking example of an empirical folk remedy — a tree bark used for fevers — that turned out to contain a genuinely active antimalarial compound, validated by chemistry centuries after it was first adopted.
Chloroquine, Artemisinin, and Tu Youyou
The twentieth century brought synthetic antimalarials. The most important early one was chloroquine, a synthetic compound that emerged from German and Allied research around the Second World War and became, for decades, the cheap, effective, mass-deployed backbone of malaria treatment and prevention worldwide. Its success was eventually undermined by its own ubiquity: Plasmodium falciparum evolved widespread chloroquine resistance from the late 1950s onward, spreading across continents and reopening the urgent search for new drugs.
That search produced one of the most remarkable chapters in modern medicine. In China, a secret military research programme launched in 1967 and known as Project 523 screened traditional remedies for antimalarial activity, driven in part by chloroquine-resistant malaria devastating soldiers during the Vietnam War. The pharmaceutical chemist Tu Youyou, drawing on a fourth-century Chinese text describing sweet wormwood (qinghao) for intermittent fevers, focused on the plant Artemisia annua. By devising a low-temperature extraction that preserved the active ingredient, her team isolated, in 1972, the compound now called artemisinin (in Chinese, qinghaosu). Artemisinin and its derivatives act fast against the parasite and form the basis of today’s artemisinin-based combination therapies, the current first-line treatment for falciparum malaria. For this discovery, Tu Youyou was awarded the Nobel Prize in Physiology or Medicine in 2015 — the first Chinese woman, and the first Chinese scientist working in mainland China, to win a Nobel in a scientific category.
The arc from quinine to chloroquine to artemisinin is also a cautionary tale: each great antimalarial drug eventually met resistance, and partial resistance to artemisinin has now been reported in parts of Southeast Asia and Africa. The history of malaria treatment is not a finished victory but an ongoing arms race between human ingenuity and a parasite that has been adapting to us for a very long time.
Malaria and the Human Genome
Malaria has been such a relentless killer for so long that it has literally left its mark on human DNA. In regions where the disease was historically common, evolution favoured several inherited blood traits that — in their carrier form — offer partial protection against severe malaria, even though in their full form they cause serious disease. This is one of the clearest examples in all of biology of what is called balancing selection: a gene that is harmful in one dose can persist in a population because it is protective in another.
The best-known example is sickle cell trait. People who inherit one copy of the sickle haemoglobin gene are usually healthy and are substantially protected against life-threatening falciparum malaria; people who inherit two copies develop sickle cell disease. The geographic overlap between historical malaria and the sickle gene is striking and was one of the first molecular links ever drawn between an infection and human heredity. Similar partial protection is associated with the thalassemia traits, with glucose-6-phosphate dehydrogenase (G6PD) deficiency, and with the absence of the Duffy blood-group antigen, which makes many West and Central African populations resistant to Plasmodium vivax.
This genetic legacy is a sober reminder of malaria’s evolutionary weight. The disease did not merely kill people; it reshaped the human gene pool, leaving behind blood disorders that remain major health concerns today precisely because they were, in part, ancient defences against the parasite. The full clinical picture of these conditions is covered in the linked Hematology articles.
Legacy: From Bad Air to a Global Fight
Within a single generation around 1900, malaria was transformed from a disease of mysterious “bad air” into a precisely understood parasitic infection with an identified cause and a known mode of transmission. That knowledge changed everything: once it was clear that Anopheles mosquitoes carried the parasite, control could target the mosquito and its breeding sites. Drainage of swamps, screening and netting of homes, and later insecticides made it possible to push malaria out of large regions, including the southern United States and much of Europe, where the disease had once been endemic.
The twentieth and twenty-first centuries saw enormous, only partly successful campaigns — the use and later restriction of the insecticide DDT, a Global Malaria Eradication Programme, the rise of insecticide-treated bed nets and rapid diagnostic tests, artemisinin-based combination therapies, and, very recently, the first malaria vaccines recommended for children in high-burden areas. Yet malaria remains one of the world’s great killers, causing hundreds of thousands of deaths a year, most of them young children in sub-Saharan Africa, and the parasite continues to evolve resistance to both drugs and insecticides.
The history of malaria is therefore a story still being written. It runs from Hippocrates’ fever charts through a four-hundred-year-old misnomer, through Laveran’s microscope and the Ross–Grassi mosquito, through a tree bark and a Chinese herb, and into modern laboratories and vaccine trials. For a free public-knowledge site, the honest version of that story — crediting the right people, marking the hypotheses, and naming both the triumphs and the unsolved problems — is the version worth telling.
Research Papers and References
The references below combine authoritative biographical and historical sources with curated PubMed topic-search links into the malaria literature. Classical primary sources (the Hippocratic texts; the writings of Celsus) are named in the article as historical sources rather than as modern citations. Each link opens in a new tab; PubMed links open at the U.S. National Library of Medicine.
- Laveran CLA. A newly discovered parasite in the blood of patients suffering from malaria. Parasitic etiology of attacks of malaria (Classics in Infectious Diseases reprint). Reviews of Infectious Diseases. 1982;4(4):908-911. — PubMed: PMID 6750753
- The Nobel Prize in Physiology or Medicine 1907 — Alphonse Laveran (parasite discovery, 1880). — NobelPrize.org — Laveran 1907
- The Nobel Prize in Physiology or Medicine 1902 — Ronald Ross (mosquito transmission of malaria). — NobelPrize.org — Ross 1902
- The Nobel Prize in Physiology or Medicine 2015 — Tu Youyou (artemisinin). — NobelPrize.org — Tu Youyou 2015
- Cox FEG. History of the discovery of the malaria parasites and their vectors. Parasites & Vectors. 2010;3:5. — doi:10.1186/1756-3305-3-5
- Tu Y. The discovery of artemisinin (qinghaosu) and gifts from Chinese medicine. Nature Medicine. 2011;17(10):1217-1220. — doi:10.1038/nm.2471
- Capanna E. Grassi versus Ross: who solved the riddle of malaria? International Microbiology. 2006;9(1):69-74. — PubMed: PMID 16636993
- Etymologia: malaria. Emerging Infectious Diseases. 2012;18(10):1716. — PMC: Etymologia — malaria
- Malaria history, naming, and the miasma theory — PubMed: malaria history, miasma, name origin
- Hippocrates and the early clinical description of tertian and quartan fevers — PubMed: Hippocrates, tertian and quartan fevers
- Quinine, cinchona bark, and the history of antimalarial therapy — PubMed: quinine and cinchona history
- Chloroquine resistance in Plasmodium falciparum — emergence and spread — PubMed: chloroquine resistance history
- Sickle cell trait, thalassemia, G6PD deficiency, and protection against malaria (balancing selection) — PubMed: malaria and protective blood traits
- Naming of the genus Plasmodium (Marchiafava & Celli, 1885) and the human malaria species — PubMed: Plasmodium species history
External Authoritative Resources
- World Health Organization — Malaria fact sheet
- U.S. CDC — About Malaria
- PubMed — Research on the history and discovery of malaria