This book examines the relationship between the indigenous peoples of northern Ecuador and disease, especially those infections introduced by Europeans during the sixteenth century. It addresses an important and often overlooked element in the history of Amerindian populations: their biological adaptability and resilience. But it is more than a history of disease incidents, medical responses, and population trends. The history of the biological experience under colonial rule. It differs from other studies in the field by its emphasis on the relationship between biological and social responses.