Constantin Levaditi

Constantin Levaditi (1 August 1874 – 5 September 1953) was a Romanian physician and microbiologist, a major figure in virology and immunology (especially in the study of poliomyelitis and syphilis).

Born in Galaţi, he studied at the Matei Basarab College in Bucharest and at the Carol Davila University of Medicine and Pharmacy, where he studied under Victor Babeş; he then trained at the Collège de France in Paris, and with Paul Ehrlich in Frankfurt. In 1900, he was accepted by Ilya Ilyich Mechnikov to work in his team at the Pasteur Institute in Paris. Sometime after, Pierre Paul Émile Roux awarded him an independent laboratory within the Institute.

With Karl Landsteiner, he discovered in 1909 the presence of the polio virus in tissues other than nervous. He expanded on these studies during a polomyelitis outbreak in Sweden, working with Scandinavian researchers (among them Karl Oskar Medin); he was able to isolate the poliovirus on tissue explant and made precious observations on its characteristics. Together with Carl Kling, he authored the first monograph dedicated to the disease, La Poliomyélite aiguë épidémique (1913). His work was the basis for the development of vaccinea (by Jonas Salk and Albert Sabin).

In his studies of syphilis, Levaditi introduced new techniques in serology, and recommended bismuth in its treatment.

After 1920, he continued his work in Romania, where he taught at the University of Medicine and Pharmacy. He was a member of the Académie Nationale de Médecine and an honorary member of the Romanian Academy.