Isolated in 1894 within fifteen days of arriving in Hong Kong, the bacillus later named Yersinia pestis provided the first clear understanding of the bubonic plague. Alexandre Yersin, a Swiss-born physician and biologist who eventually took French citizenship, shifted the trajectory of microbiology by identifying the transmission mechanisms linking rodents to the human infection.
Foundational Research in Bacteriology
Born in Aubonne in 1863, Yersin studied medicine at the University of Lausanne before continuing his education at Marburg and the Hôtel-Dieu de Paris. In 1886, he joined Louis Pasteur's laboratory at the École Normale Supérieure. By 1889, he became a collaborator at the Pasteur Institute. Working alongside Émile Roux, he identified that Corynebacterium diphtheriae secreted a soluble toxin, marking a significant advancement in the study of bacterial pathology. He also contributed to the early development of an anti-rabies serum.
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Between 1890 and 1894, Yersin served as a ship's doctor for Messageries Maritimes. During this period, he conducted three expeditions across French Indochina, covering regions now known as Vietnam, Laos, and Cambodia. The French government dispatched him to Hong Kong in 1894 to investigate a catastrophic plague outbreak. Upon isolating the pathogen, he returned to Paris to work with Émile Roux, Albert Calmette, and Amédée Borrel on an anti-plague serum, eventually establishing a laboratory in Nha Trang to manufacture it.
Agricultural Innovation in Indochina
After settling in Nha Trang, Yersin expanded his efforts into agronomy. He secured a government concession in 1897 to create an agricultural station at Suoi Dau, where he pioneered the cultivation of rubber trees. In 1915, he opened a station at Hon Ba, facilitating the acclimatization of the cinchona tree, the source of quinine used to treat malaria. His agricultural efforts also included the introduction of cacao and coffee to the region, and his cinchona production proved vital to local medical needs during the Second World War.
Administrative and Academic Contributions
Yersin was instrumental in the establishment of the Hanoi Medical University, serving as its first Headmaster starting on 8 January 1902 under the direction of Governor-General Paul Doumer. His professional service was recognized through memberships in the Académie des sciences d'outre-mer and the Académie Nationale de Médecine. He held the position of honorary director of the Pasteur Institute and sat on its Board of Administration. He remained in Indochina until his death in 1943 in Nha Trang.
Fast facts
- Born: 1863, Aubonne
- Died: 1943, Nha Trang
- Education: University of Lausanne
- Key Discovery: Yersinia pestis (1894)
- Primary Affiliation: Pasteur Institute
- Military Rank: Colonel
- Legion of Honour: Grand Officer (1939)
- Languages: French
Questions readers ask
Did Yersin ever return to Europe after moving to Asia?
No, he remained in French Indochina following his arrival in the region.
Why was Yersin known as Ông Năm in Vietnam?
The nickname reflected his rank as a Colonel in the French army, which featured five horizontal stripes on his insignia.
Achievements
- Leconte Prize — 1927
- Grand Officer of the Legion of Honour — 1939
- Grand officer of the Order of the Dragon of Annam — 1935
- French Order of Academic Palms — 1890
- Knight of the Legion of Honour — 1894
- Held posts at Pasteur Institute, Messageries Maritimes and Hanoi Medical University
- Fields: bacteriology, typhus and typhus vaccine
