Manson Medal for Tropical Medical Research

Abstract

THE Manson medal for tropical medical research, given triennially by the Royal Society of Tropical Medicine and Hygiene, has this year been awarded to Dr. Theobald Smith. In association with Kilborne in 1893, Theobald Smith showed that red-water fever in cattle is transmitted by ticks, and at the same time demonstrated the passage of infection through the ova of one generation of ticks to the next. This discovery proved that a protozoal parasite of mammals could be disseminated by the bite of a blood-sucking arthropod. Probably because Theobald Smith was dealing with a cattle rather than a human disease, this great event in the history of medicine received scant recognition, though it preceded the better-known work of Bruce on the transmission of sleeping sickness and that of Ross on malaria. Indeed, Theobald Smith was the first to transfer the insect transmission theory of protozoal disease from the realms of hypothesis to those of established fact. In 1904, Theobald Smith reported anaphylaetic symptoms in dogs and rabbits, and, in a letter to Ehrlich, wrote the original description of the classical anaphylactie shock in guinea-pigs often known as the Theobald Smith phenomenon. In 1907 he proved that it was possible to immunise guinea-pigs actively by the injections of a balanced mixture of diphtheria toxin and antitoxin, and two years later suggested further investigations of the method with the view of its ultimate application to human beings, thus anticipating Von Behring and Park's work by several years. The previous recipients of the Manson medal have been Sir David Bruce (1933), Senator Ettore Machiafava (1926), and Sir Ronald Ross (1929).