Virgin Soil Epidemics as a Factor in the Aboriginal Depopulation in America

Abstract

URING the last few decades historians have demonstrated increasing concern with the influence of disease in history, particularly the history of the New World. For example, the latest generation of Americanists chiefly blames diseases imported from the Old World for the disparity between the number of American aborigines in I492 new estimates of which soar as high as one hundred million or approximately one-sixth of the human race at that time and the few million pure Indians and Eskimos alive at the end of the nineteenth century. There is no doubt that chronic disease was an important factor in the precipitous decline, and it is highly probable that the greatest killer was epidemic disease, especially as manifested in virgin soil epidemics.' Virgin soil epidemics are those in which the populations at risk have had no previous contact with the diseases that strike them and are therefore immunologically almost defenseless. The importance of virgin soil epidemics in American history is strongly indicated by evidence that a number of dangerous maladies smallpox, measles, malaria, yellow fever, and undoubtedly several more were unknown in the pre-Columbian New World.2 In