1894: Two Scientists Discovered The Bacteria That Causes The Plague At The Same Time

By Jacob Shelton
Man being injected by doctor during an outbreak of bubonic plague in Karachi, India. Photograph, 1897. (Wellcome Collection/Wkimedia Commons)

By 1894, the bubonic plague had been, well, plaguing the globe for centuries. Scientists had been trying for just as long to figure out just what the disease was and how to stop it, but that fateful year, two of them succeeded at the same time.

Kitasato And Yersin

Kitasato Shibasaburō and Alexandre Yersin were two of the most celebrated bacteriologists in their field way before they discovered the bacillus responsible for the bubonic plague. Yersin, who had dual French and Swiss citizenship, studied under Louis Pasteur before working with Emile Roux to develop an anti-rabies serum. He practiced medicine throughout Asia, and in 1894, he was sent to Hong Kong at the request of the French government and the Pasteur Institute to investigate the Plague.

Kitasato was born in Tokyo in 1853. After studying medicine in Japan, he traveled to Berlin, where he studied under microbiologist Robert Koch, growing the first tetanus bacillus sample in pure culture and developing a serum therapy for tetanus with Nobel Prize–winner Emil von Behring. After setting up the Institute for Study of Infectious Diseases in Japan, he traveled to Hong Kong to study the Plague as well. While these two would never cross paths, the combination of their independent research changed the world.