During the first 200 years of European exploration and settlement of the Americas, native populations experienced catastrophic die-offs from the introduction of acute infectious diseases.
Pinpointing which parasites were responsible for this decimation is not a simple matter. European knowledge of the infectious disease process was primitive in the sixteenth and seventeenth centuries, with the result that conquerors, settlers, and clergy were ill-prepared to describe the illnesses they witnessed.
Statements that simply describe the death experience of native peoples are the most common. In the Roanoke documents of 1588, for instance, T. Hariot described native death from disease, but he attributed the outbreaks to witchcraft:There was no towne where he had any subtile devise practiced against us, we leaving it unpunished or not revenged (because we sought by all meanes possible to win them by gentlenesse) but that within a fewe dayes after our departure from every such town, the people began to die very fast, and many in short space, in some townes about twentie, in some fourtie, and in one sixe score, which in trueth was very many in respect to their nombers. This happened in no place that we could Iearne, but where we had bene, where they used a practice against us, and after such a time. The disease, also strange, that they neither knew what is was, not how to cure it. (Hariot 1973)
The quality of disease descriptions in the Americas greatly improved during the eighteenth century. A description of the frequency of colds among the Natchez stands in stark contrast to Hariofs sixteenth-century description of disease:
Colds, which are very common in winter, likewise destroy great numbers of natives. In that season they keep fires in their huts day and night; and as there is no other opening but the door, the air within the hut is kept excessively warm without any free circulation; so that when they have occasion to go out, the cold seizes them, and the consequences are almost always fatal. (Le Page du Pratz 1975)
Because of epidemiological advances, it is easier for historical epidemiologists to reconstruct disease etiology in the Americas from the eighteenth century to the present.
Unfortunately, focusing epidemiological reconstructions on later centuries to the exclusion of the sixteenth and seventeenth centuries is comparable to measuring the destruction of a hurricane that strikes the Gulf Coast by its effect in St. Paul, Minnesota. As has been stressed (Burnet and White 1972), the earliest epidemics among virginsoil populations are the most severe.Although new pathogens, such as cholera (Benen- son 1976a), reached America’s shores in later centuries, they operated at reduced scales, affecting only those who had survived a microbial war of 200 years. Thus, this essay attempts to reconstruct the group of diseases that spread to the Americas between A.D. 1492 and 1700. Although multicellular organisms, including round- and pinworms, undoubtedly reached the Americas during the sixteenth and seventeenth centuries, this discussion focuses largely on unicellular or Subcellular organisms, viruses, bacteria, and protozoa, that are defined as acute and infectious and that periodically erupt as epidemics.