Discoverer of the pathogen of Weil's disease@
Ryokichi Inada


@Dr. Ryokichi Inada graduated from Medical College of Tokyo Imperial University with top honors in 1900 and then he studied in Germany from 1902 until 1905 when he was appointed as the first professor of the Fukuoka Medical College of Kyoto Imperial University (present-day Kyushu University) Department of Internal Medicine I.

cʂ Dr. Inada discovered the pathogen of Weil's disease in 1914 and detailed research was carried out based on a careful research plan and extensive scholarship. The findings were published in September 1915 as "Theory on Spirochaeta icterohaemorrhagiae (japonica)", which comprehensively covers the discovery of the pathogen, infection source and route, clinical and pathological aspects, diagnosis, treatment and prevention from infection. Dr. Inada moved to Tokyo Imperial University Department of Internal Medicine upon his appointment as professor in 1920, received the Order of Cultural Merit in 1944 and died in 1950.

Strain Ictero No.1, which was first isolated by Dr. Inada and his colleagues in 1914, was then cultured and maintained by researchers in Japan. The strain was formally recognized as the leptospira type strain by the International Committee on Systematic Bacteriology, Subcommittee on the Taxonomy of Leptospira held in Osaka in 1990, 76 years after its discovery.

Along with Dr. Shibasaburo Kitazato, Dr. Inada was nominated as one of the first Japanese to be presented with a Nobel Prize for his remarkable achievements.

Written by Hiromi Ishibashi, Ex-associate Professor of Kyushu University Graduate School of Medical Sciences Department of Medicine and Biosystemic Science; Chief of National Hospital Organization Nagasaki Medical Center Clinical Research Center