A Geographical Study of "Swimmers' Itch" in the United States and Canada

Abstract

FOR the last 50 years it has been known that many persons develop a skin eruption after swimming or wading in certain lakes in the midwestern part of the United States and Canada (Fig. i). This eruption, called colloquially swimmers' itch and technically cercarial or schistosome dermatitis, is a of place that is, it can be acquired only at certain. places and is not directly communicable from person to person. The broad area of its occurrence changes little from year to year, yet at certain localities within that area the disease has never occurred, though conditions seem to be favorable, and at others it varies in intensity and in some years does not even appear. What physical and human elements of the environment combine to account for these facts? The answer is of interest not only to medical geography but to the economy of the affected localities, many of which are summer resorts. In some of them summer income and property values have been seriously lowered in consequence of the disease.