Epidemiologic classics of Carter, Maxcy, Trudeau, and Smith

Four great epidemiologists whose work so concisely linked clinical observations, epidemiologic clues, and logical preventive measures are discussed. Henry Rose Carter set the stage for the Walter Reed successes in Cuba by showing that 9-16 days must elapse after contact before yellow fever develops. This provided the link for the Reed group to allow the "virus" to incubate in the mosquito before becoming infectious. Kenneth Maxcy clarified the controversy between endemic typhus fever and Brill's disease in the southeastern United States. His clinical, epidemiologic, and laboratory findings led him to propose that the causative organism (Rickettsia typhi) was in rodents and the probable vector, fleas. When confirmed, effective control measures were applied. Two other American investigators, Edward L. Trudeau and Theobald Smith, helped prove Robert Koch wrong on three counts: (1) Tuberculin is not an effective therapeutic agent for tuberculosis; (2) there are two distinct types of tubercle bacillus, human and bovine; and (3) the bovine form of Mycobacterium tuberculosis is remarkably pathogenic for humans. The significance of these findings is unlimited.