Alexandre-Émile-John Yersin

Alexandre-Émile-John Yersin was one of the discoverers of the plague bacillus, now named Yersinia pestis. In 1884, with Émile Roux, he demonstrated the existence of diphteria exotoxin.

Yersin's father, also named Alexandre Yersin (1825-1863), was a teacher of natural sciences in Aubonne and Morges. He died two weeks before the birth of his son Alexandre-Émile-John.

As a child Alexandre Yersin had a keen interest in nature, collecting insect that he studied carefully. He grew up Morges, where he knew Victor Morax (1866-1935). He received his secondary education in Lausanne before he entered the university there. He subsequently attended the University of Marburg and the Paris Faculty of Medicine, where he worked in professor André Victor Cornil's (1837-1908) laboratory at the Hôtel-Dieu.

An accident brought him in contact with Pierre-Paul-Émile Roux (1853-1933). Yersin had cut himself while performing an autopsy on a patient who had died of rabies, and was saved by an injection of a new therapeutic serum given to him by Roux. In 1888 Roux hired him as his assistant in his research work on rabies. From Paris, Yersin moved on to Berlin to continue his bacteriological studies under Heinrich Hermann Robert Koch (1843-1910), conducting studies on the tubercle bacillus. In 1889 he was engaged by Roux to prepare and teach a course in microbiology at the Pasteur Institute in Paris, and began his own research, with Roux, on the toxic properties of the diphteria bacillus.

Upon his return to Paris, Yersin began his own research with Roux, at the Institut Pasteur, In 1889, however, he suddenly embarked as a ship’s doctor on a steamer bound for Saigon and Manila. He returned to Paris and left again for Indochina; and during three dangerous expeditions into the interior, he discovered the high plateau of Langbiang, where he founded a small colonial village. The area soon became a vacation centre for Europeans, and the city of Dalat was developed there. In 1935 the municipal authorities established the Lycée Yersin at Dalat.

A sailor in Hong Kong
In 1890 Yersin suddenly left Europe to serve as a physician for the Messageries maritimes aboard a steamer bound for Saigon and Manila, and soon began his four-year exploration of the central region of Indochina. He discovered the sources of the Dong Nai River and explored the Lang Bian Plateau, where he recommended that a town, the future Da Lat, be built. In 1894 he joined the colonial health service – Corps de santé des colonies – and was sent to Hong Kong to conduct research on bubonic plague epidemic that was sweeping through China.

However, Yersin was not the only bacteriologist to rush to the scene. The Japanese bacteriologist Shibasaburo Kitasato (1852-1931) arrived a few days before Yersin. Kitasato was championed by Dr James A. Lowson, a naval surgeon who was Superintendent of the Government Civil Hospital. Within a few days of his arrival, Kitasato found a bacillus and announced it to the world via telegraph. His discovery was published in The Lancet of August 13 that year.

Yersin arrived in Hong Kong on June 15th, 1894 and seven days later, working in a small bacteriological research laboratory set up for him, he isolated the plague bacillus.

Kitasato published his findings in Japanese and English; Alexandre Yersin published in French. People in different parts of the world credited one or the other with the discovery, depending which journals they had read. Yersin named the organism Pasteurella pestis after his teacher, but since 1970 the bacillus has been known as Yersinia pestis.

Nha Trang – his new home
The next year, 1895, Yersin established a laboratory at Nha Trang. There he prepared serums against plague in human beings and cattle and studied cattle diseases, tetanus, cholera, and smallpox. To finance the laboratory, designated the Pasteur Institute of Nha Trang in 1903, he undertook the cultivation of corn (maize), rice, and coffee and introduced the rubber tree (Hevea brasiliensis) to Indochina.

In 1904 he was recalled to Paris and continued his research at the Institut Pasteur, of which Roux had become director. With Léon Charles Albert Calmette (1863-1933) and Amédée Borrel (1867-1936) he made the important observation that certain animals can be immunized against the plague through the injection of dead plague bacteria.

He then returned to Nha Trang, where a branch of the Institut Pasteur had been established under his direction. There, in modest laboratories, Yersin perfected an antiplague serum that made it possible to reduce the death rate from 90 percent to about 7 percent.

With the assistance of Paul Doumer (1857-1932), then government general of Indochina, a medical school was founded at Hanoi; Yersin directed this centre of study and research for many years. Through Yersin’s work Indochina was able to control the epidemics that beset the country, especially malaria. In recognition of his medical achievements, the French government appointed Yersin honorary director of the Institut Pasteur in 1933.

The landowner
Besides his activity in science and medicine in Indochina, Yersin conducted research in agronomy. He had a ranch in Nha Tranf where he raised horses. He also contributed to the Vietnamese rubber industry, as he is responsible for introducing the Brazilian rubber tree to Vietnam. During the years 1920-1923 Yersin was also responsible for the first quinquina plantations in Vietnam, where quinine (Cinchona ledgeriana) are produced.

His interest in the cultivation of grains and in soil conditions led him to initiate a series of ecological studies. He also reflected on the natural history of Indochina, having become fascinated by the flora and Fauna of his adopted country. Yersin became deeply concerned over the needs of the sick and the poor and fought hard against the exploitation of the lower classes. At Nha Trang he lived a simple life and was beloved by the people in the region for his humility and care he gives to the people. The locals lovingly calls his home Lau Ong Nam (Home of Fifth Uncle) or Thap Nga (Ivory tower).

In 1940, Alexandre Yersin in poor health, returned to France for the last time. In 1941, he returned to his beloved home in Nha Trang where he remained and passed away in January 3, 1943 at Suô'i Giao southwest of Da Lat, at the age of 80. In his will, he requested to be buried in Nha Trang, close to his beloved people. Every year, on March 1st, out of respect and gratitude to his contribution to this region, many of the inhabitants still come to his grave, bringing joss-stick and fruits as offerings.

The Alexandre Yersin French International School Ha Noi is named in his honour. This school is a not-for-profit organization under the guardianship of the Embassy of France in the Socialist Republic of Viet Nam.

We thank Patrick Jucker-Kupper, Switzerland, for information submitted.

On diphteria

• Contribution à l'étude de la diphtérie. Written with Emile Roux.
  Annales de l'Institut Pasteur, 1888, 2 (12): 629-661.
• Contribution à l’étude de la diphtérie.
  Annales de l’Institut Pasteur, 1888, 2: 629-661;
• Contribution à l'étude de la diphtérie. Deuxième mémoire.
  With Emile Roux, Annales de l'Institut Pasteur, 1889, 3 (6): 273-288.
• Contribution à l'étude de la diphtérie. Troisième mémoire.
  With Emile Roux. Annales de l'Institut Pasteur, 1890, 4 (7): 385-426. On tuberculosis
  
• De l'action de quelques antiseptiques et de la chaleur sur le bacille de la tuberculose. Annales de l'Institut Pasteur, 1888, 2: 60-65.
• Etude sur le développement du tubercule expérimental.
  Thèse de la faculté de Médecine de Paris 26 mai 1888.
  Annales de l'Institut Pasteur, 1888, 2: 245-266.
• Etude sur le développement du tubercule expérimentale.
  Sceaux, Charaire et fils, 1888, 31 pages.
• Analyse de l'article de Stschastny : sur les relations entre les bacilles de la tuberculose et les cellules. Annales de l'Institut Pasteur, 1889, 3 (2): 93-94.
• Analyse de l'article de H. Kuhne : sur la coloration des bacilles dans les nodules morveux.
  Annales de l'Institut Pasteur, 1889, 3 (1): 44-45. On plague
  
• Sur la peste de Hong Kong.
  Communication à L'Académie des Sciences le 30-7-1894.
  Comptes rendus de l'Académie des Sciences, 1894, 119: 356.
• La peste bubonique à Hong Kong.
  Annales de l'Institut Pasteur, 1894, 8: 662-667.
• La peste bubonique à Hong Kong.
  Archives de Médecine Navale, 1894, 62: 256-261.
• La peste bubonique. Deuxième note. With A. Calmette and A. Borrel.
  Annales de l'Institut Pasteur, 1895, 9: 589-592.
• La peste bubonique. Deuxième note.
  Archives de Médecine Navale, 1895, 64: 49-52.
• Sur la peste (sérothérapie).
  Annales de l'Institut Pasteur, 1897, 11: 81-93.
• Rapport sur la peste aux Indes.
  Archives de Médecine Navale, 1897, 68: 366-372.
• Historique du premier cas de peste traité et guéri par l'emploi du sérum antipesteux. Bulletin de l'Académie de Médecine, 1897, 36: 195-199.
• Rapport sur la peste bubonique de Nha Trang (Annam).
  Annales de l'Institut Pasteur, 1899, 13: 251-261.
• L'épidémie de peste de Nha Trang de juin à octobre 1898.
  Annales d'Hygiène et de Médecine Coloniales, 1899, 2: 378-390.
• Vaccination par atténuation du coccobacille de la peste.
  In collaboration with C. Carré. 13e Congrés International de Médecine, Paris, 1900.
• Les épidémies de peste en Extrême-Orient.
  In collaboration with Paul-Louis Simond (1858-1947).
  13e Congrés International de Médecine, Paris, 1900. On contagious diseases in live-stock
  
• Notes succintes sur une épizootie de buffles, sur la typhomalarienne et la bilieuse hématurique. Archives de Médecine Navale, 1895, 64: 49-52.
• Note sur la fièvre bilieuse hématurique.
  Comptes Rendus de la Société de Biologie, 1895, 47: 447-449.
• Expériences sur la peste bovine.
  Bulletin Economique de l'Indochine, 1898, 2: 245.
• Traitement de la peste bovine.
  In collaboration with C. Carré and Fraimbault.
  Annales d'Hygiène et de Médecine Coloniales, 1899, 2: 175-182.
• Note sur les épizooties des bovins en Indochine.
  Annales d'Hygiène et de Médecine Coloniales, 1903, 6: 467-469.
• Etudes sur quelques épizooties de l'Indochine.
  Annales de l'Institut Pasteur, 1904, 18 (7): 417-449. On the exploration of the Moïs region
  
• Notes recueillies pendant trois voyages chez les Moïs de l'Indochine.
  Archives de Médecine Navale, 1894, 61: 310-312.
• Explorations et souvenirs du Docteur Yersin (souvenirs recueillis par l'Institut Pasteur de Dalat en mai 1956. [Dalat : Institut Pasteur, 1956].
• Récit des premières explorations du Docteur Yersin dans la chaîne annamitique, publié dans la revue Indochine de 1942 à 1943. Comprend :
  
• Premier contact avec les pays Moïs de l'Annam.
  
• Voyage de Nha Trang à Stung-Treng par les pays Moïs (première, deuxième et dernière parties).
  
• Rencontre avec des pirates sur le plateau Moï.
  
• Première reconnaissance du plateau du Lang-Bian.
  
• Un mois chez M'Siao (juillet-août 1893).
  
• De Nha Trang à Tourane par les plateaux Moïs.
  
• De Nha Trang à Tourane par les pays Moïs. On the Institut Pasteur in Nhatrang
  
• L'Institut Pasteur de Nha Trang, Annam.
  Annales d'Hygiène et de Médecine Coloniales, 1900, 3: 506-520.
• L'Institut Pasteur de Nha Trang, Annam.
  Bulletin Economique de l'Indochine, 1900: 253-265. On the acclimatization of quinquina and the cultivation of hevea
  
• La station d'altitude du Hon Ba (Annam), les essais agricoles qui y sont poursuivis.
  Revue de Botanique Appliquée et d'Agriculture Coloniale, 1925, 5: 574-582.
• Essais d'acclimatation de l'arbre à quinquina en Indochine. Première note.
  Revue de botanique appliquée et d'agriculture coloniale, 1927, 7: 250-254 and 331-338.
• Note sur divers essais agricoles entrepris aux stations d'altitude des Instituts Pasteur d'Indochine. Deuxième note. In collaboration with A. Lambert.
  Revue de botanique appliquée et d'agriculture coloniale, 1927, 7: 809-816.
• Note sur divers essais agricoles entrepris aux stations d'altitude des Instituts Pasteur d'Indochine. Troisième note. In collaboration with A. Lambert.
  Revue de botanique appliquée et d'agriculture coloniale,1928, 8: 119-122.
• Essais d'acclimatation de l'arbre à quinquina en Indochine.
  Archives de l'Institut Pasteur d'Indochine, 1928, 8: 5-22.
• Note sur divers essais agricoles entrepris aux stations d'altitude des Instituts Pasteur d'Indochine. Quatrième note. In collaboration with A. Lambert.
  Revue de botanique appliquée et d'agriculture coloniale, 1931, 11: 301-304.
• Longue survie d'hévéas brisés par un typhon.
  Comptes rendus de l'Académie des Sciences, 1932, 194: 1620.
• Essais d'acclimatation de l'arbre à quinquina en Indochine. Cinquième note.
  In collaboration with A. Lambert.
  Revue de Botanique Appliquée et d'Agriculture coloniale, 1935, 15: 225-234.
• Note sur les essais d'acclimatation des quinquinas entrepris en Indochine par l'Institut pasteur.
  Bulletin de la Société Médico-chirurgicale de l'Indochine, 1936: 594-595.
• Essais d'acclimatation de l'arbre à quinquina en Indochine. Sixième note.
  In collaboration with A. Lambert.
  Revue de Botanique Appliquée et d'Agriculture Coloniale, 1939, 19: 237-242. On various scientific subjects
  
• Tumeur mélanique de la plante du pied.
  Annales de l'Institut Pasteur, 1887, 1 (3): 142.
• Analyses de trois articles : P. Liborius : « Recherches sur l'action désinfectante de la chaux », O. Bujwid : « une réaction chimique pour les bacilles du choléra », Fischer : « Recherches bactériologiques pendant un voyage aux Indes.
  Annales de l'Institut Pasteur, 1887, 1 (6): 318-319.
• Note sur un cas de fièvre récurrente en Indochine.
  Comptes rendus de la Société de Biologie, 1906, 60: 1037-1038.
• Une maladie rappelant le typhus exanthématique observée en Indochine.
  In collaboration with J. J. Vassal.
  Bulletin de la Société de Pathologie Exotique, 1908, 1: 156-164.
• La Simaroubine dans la dysenterie amibienne.
  Written with L. Braudat and Lalong-Bonnaire.
  Comptes rendus des travaux du troisième Congrés Biennal de la Far Eastern Association of Tropical Medicine, Saigon, 1913: 101-105.
• Quelques observations d'électricité atmosphérique en Indochine.
  Comptes rendus de l'Académie des Sciences, 1930, 191: 366-368. Publications on Alexandre Yersin – Periodicals
• Bernard Noël:
  Yersin 1863-1943. Annales de l'Institut Pasteur, 1943, 69: 129-134.
• Bernard Noël:
  Yersin 1863-1943. La Presse médicale, 1943, 17: 237.
• Lacroix
  Yersin. Comptes Rendus de l'Académie des Sciences, 1943, 216 (11): 361-364.
• G. Ramon:
  Alexandre Yersin, 1863-1943.
  Bulletin de l'Académie de Médecine, 1943, 25/26: 382.
• N. Bernard, P. Hauduroy, G. Olivier:
  Yersin et la peste. Lausanne, 1944.
• Y. Mafart:
  Alexandre Yersin. 1863-1943. Médecine Tropicale, 1965, 25 (4): 427-438.
• J. C. Rosenberg
  Alexandre Yersin. New England Journal of Medicine, 1968, 278 (5): 261-263.
• H. H. Mollaret:
  Alexandre Yersin tel qu'en lui-même enfin...Les révélations d'une correspondance inédite échelonnée de 1884 à 1926.
  Nouvelle Presse médicale, 1973, 2(39): 2575-2580.
• H. H. Mollaret:
  Souvenirs inédits d'A. Yersin sur Pasteur et l'Institut Pasteur.
  Médecine et maladies infectieuses, 1973, 3 (5): 191-201.
• H. Jacotot:
  Yersin en son temps.
  Bulletin de l'Association des anciens élèves de l'Institut Pasteur, 1973, 57: 74-79.
  Bulletin de l'Association des anciens élèves de l'Institut Pasteur, 1974, 58: 110-114.
• J. Brosselet:
  De Morges à Nha Trang, itinéraire d'Alexandre Yersin.
  Médecine et Hygiène, 1974, 32: 1576-1578.
• Saint-Restitut:
  Alexandre Yersin, 1863-1943. Gazette médicale de France, 1980, 87 (33): 4519-4522.
• Brisou:
  Alexandre Yersin, médecin des troupes coloniales.
  Bulletin de l'Association des anciens élèves de l'Institut Pasteur, 1993, 135: 19-30.
• T. Salomon:
  Alexandre Yersin and the plague bacillus.
  Journal of Tropical Medicine & Hygiene, 1995, 98 (3): 209-212. Books/Monographs
• P. Hauduroy:
  Les découvertes de Yersin et les méthodes pastoriennes.
  Schweizerische medizinische Wochenschrift, Basel, 1943, 24: 750-751.
• Bernard Noël:
  Yersin (1863-1943).
  Paris, Ancienne Imprimerie de la Cour d'Appel, 1943, 15 pages.
• Henri Jacotot:
  Le docteur Alexandre Yersin : esquisse de ce qu'il fut et de ce qu'il fit.
  Saigon, S.I.L.I., 1944, 43 pages.
  Extrait du Bulletin de la Société des Etudes Indochinoises. 1er trimestre 1944.
• H. Buess:
  Recherches, découvertes et inventions de médecins suisses. Basel, 1946.
• Bernard Noël:
  Yersin : pionnier, savant, explorateur, 1863-1943.
  Paris, La Colombe, 1955, 191 pages.
• H. Mollaret Henri, Jacqueline Brossollet:
  Alexandre Yersin, le vainqueur de la peste.
  Paris, Fayard, 1985, 320 pages.
• Henri H. Mollaret, Jacqueline Brossollet:
  Alexandre Yersin 1863-1943 : un pasteurien en Indochine.
  Paris, Belin, 1993, 379 pages.
• Elisabeth du Closel:
  Docteur Nam : la fabuleuse histoire de l'homme qui soigna la peste.
  Paris, Albin Michel, 1996, 251 pages.