Summary

Recent events have drawn world attention to “mythological diseases” such as anthrax, plague and smallpox, which have been out of the spotlight for some decades. Much of our current knowledge of epidemic intervention and disease prevention was acquired over history through our experience with these very diseases, such that the sudden panic over the re-emergence of these historically well-known entities is perplexing. Over time, changes in the balance of the epidemiologic triangle have driven each of these disease systems towards a new equilibrium with which we are not familiar. While the pathogens may be similar, these are not the diseases of the past. These new disease systems are insufficiently described by the classic epidemiologic triangle, which lacks a dimension necessary for providing a valid model of the real-world effects of bioterror-related disease. Interactions within the classic epidemiologic triangle are now refracted through the prism of the global environment, where they are mediated, altered, and often amplified. Bioterror-associated diseases must be analyzed through the epidemiologic pyramid. The added dimension represents the global environment, which plays an integral part in the effects of the overall disease system. The classic triangle still exists, and continues to function at the base of the new model to describe actual agent transmission, but the overall disease picture should be viewed from the height of the fourth apex of the pyramid. The epidemiologic pyramid also serves as a practical model for guiding effective interventional measures.