Invisible Environmental History: Infectious Disease in Late Antiquity

Abstract

This study argues that the biological environment is properly a part of environmental history. The microorganisms— bacteria, viruses, protozoa—that cause infectious disease were the principal cause of mortality in ancient societies, but the particular array of pathogens was both locally specific and unstable over time. Pathogenic microbes are ecologically sensitive, so the background of local climate, and the influence of climate variability and climate change, determined patterns of disease and mortality. The connections between climate variability and climate change, on the one hand, and the disease profile of a population, on the other, are complex, and this paper traces some of the main pathways of influence, with specific reference to a few of the best known diseases and epidemic events in the later Roman period.