Yersin

Alexandre Édouard Yersin (1863–1943) was a French-Swiss physician and bacteriologist noted for identifying the plague bacillus and for his work in Southeast Asia. He studied under Louis Pasteur and later worked with the Pasteur Institute, contributing to early advances in bacteriology and immunology.

In 1894, during a plague outbreak in Hong Kong, Yersin isolated the bacterium responsible for plague, a pathogen later named Yersinia pestis in his honor. His discovery helped establish the bacterial basis of plague and informed public health responses to outbreaks.

After his work in Hong Kong, Yersin spent much of his career in French Indochina. He founded the Institut Pasteur in Nha Trang (present-day Vietnam) in 1895 and conducted field investigations of infectious diseases in the region. His expeditions and observations contributed to tropical medicine and the development of microbiology in Asia.

In addition to his plague research, Yersin engaged in zoological and botanical observations and participated in public health initiatives in Indochina. He died in 1943 in Nha Trang, Vietnam.

His legacy includes the naming of the genus Yersinia and the species Yersinia pestis in recognition of his contributions to bacteriology; his work helped shape the understanding of plague transmission and control in the late 19th and early 20th centuries.