Some diseases supposed to be peculiar to the tropics occur in parts of the United States. Once a disease is detected in an apparently new environment, it is apt to be encountered more frequently thereafter.
Few physicians were at one time aware of the prevalence of pellagra in the United States. In the early nineteen hundreds Babcock, at that time medical superintendent of the South Carolina State Hospital for the Insane, while visiting in Italy, familiarized himself with the clinical aspects of pellagra. He was convinced that the disease prevailed in the insane hospital population group of his native state, and he verified this impression. His observations attracted the attention of other psychiatrists concerned with the institutional care of the insane; eventually pellagra, especially in the Southern states, became widely recognized.
In 1909 the Rockefeller Commission, headed by Stiles, made a county by county survey of a number of Southern
TROPICAL DISEASES IN THE UNITED STATES. JAMA. 1945;129(15):1019–1020. doi:10.1001/jama.1945.02860490031011