Hideyo Noguchi

Hideyo Noguchi (野口 英世, Noguchi Hideyo; November 9, 1876 – May 21, 1928), also known as Seisaku Noguchi (野口 清作, Noguchi Seisaku), was a Japanese bacteriologist at the Rockefeller Institute during its foundation under Simon Flexner and known for his work on syphilis and contributing to the long term understanding of neurosyphilis.

During the emergence of the field of serology, he began as a research assistant to American physician Silas Weir Mitchell in his studies on snake venom at the University of Pennsylvania in 1901. Mitchell and Noguchi presented the results before National Academy of Science.

Noguchi was an early advocate of the widespread use of antivenoms before their mass production in the United States. In 1903, Noguchi went to the Statens Serum Institute in Denmark and produced one of the first antiserums to treat the North American rattlesnake bite alongside Thorvald Madsen.

In 1909, he wrote his comprehensive monograph, Snake Venoms: An Investigation of Venomous Snakes with Special Reference to the Phenomena of Their Venoms, which contained several drawings and photographs of specimens.

Beginning his career at the Rockefeller Institute during its foundation, Noguchi was the first person in the United States to confirm the causative agent of syphilis, Treponema pallidum, after it was first identified by Fritz Schaudinn and Erich Hoffmann in 1905. His most notable achievement was isolating Treponema pallidum in the brain tissues of patients with general paresis and tabes dorsals, a late stage consequence of tertiary syphilis. His discovery established the conclusive link between the physical and mental manifestation of syphilis. American educator and psychiatrist John Clare Whitehorn considered it an outstanding psychiatric achievement.

Later in his career, Noguchi developed the first serum to give partial immunity to Rocky mountain spotted fever, a notoriously lethal disease before treatment was discovered. He also suggested the name for the genus Leptospira in 1917.

However, he became increasingly erratic and inaccurate, which might have been exacerbated from contracting syphilis, progressing to neurosyphilis, discovered during his autopsy by William Alexander Young combined with his poor education from childhood. He misidentified yellow fever as being caused by the bacteria, Leptospira icterohemorrhagiae, and received scrutiny when it was later understood to be a virus with the invention of a electron microscope. Prior to this scrutiny, Noguchi died of the disease in Accra, Gold Coast during an expedition to Africa in search for its cause.

Posthumously, his work on yellow fever was overturned alongside his claims of discovering the causative agent of rabies, poliomyelitis, trachoma and his culture of syphilis could not be reproduced. His research with his colleague Evelyn Tilden after his death proved that Carrions disease and verruca peruana were the same species.

Noguchi was one of the first Japanese scientists to gain international acclaim outside of Japan for his scientific contributions. In addition, he was nominated several times for a Nobel prize in medicine between 1913 and 1927, often bringing more attention to neglected tropical diseases.

His name is attached to the spirochete, Leptospira noguchii. In 2004, Noguchi's face was featured on the 1000 yen note. The Hideyo Noguchi Africa prize is given in his honor.