George J. Armelagos
In 1969, William T. Stewart, the Surgeon General of the United States, testifying before Congress proposed that it was now 'time to close the book on infectious disease as a major health threat.' Stewart and others believed that with the development of antibiotics, vaccines and pesticides, we were on the verge of eradicating infectious disease. Buoyed by this success, Stewart's testimony before Congress was designed to position the United States public health system to meet its next health challenge: controlling chronic and degenerative diseases.
Stewart's assessment on the decline of infectious disease and the rise of chronic disease was the fulfillment of an epidemiological theory that was first proposed by Abdul Omran (1971), who argued that human populations were experiencing a shift in health and disease patterns. Omran contended that human disease history could be described as moving through a number of disease stages. Initially, humans passed through 'the age of pestilence and famine' to an 'age of receding pandemics' and finally into 'the age of degenerative and man-made diseases'. The basic feature of Omran's model (1971, 1977, 1983) was the idea that as infectious diseases were eliminated, chronic diseases would increase as the population aged. Finally, epidemiological transition theory had implications for demographic transition theory, 1 which suggested that after the decline in mortality there would be an eventual decline in fertility.
This chapter has three objectives; the first is to interpret and broaden the concept of epidemiological transition into a model that defines a number of dramatic shifts in disease patterns (Armelagos et al. 1996; Armelagos 1998; Armelagos and Barnes 1999; Barnes et al. 1999). Secondly, the evolution of emerging diseases will be discussed from the perspective of three epidemiological transitions (Barrett et al. 1998). While a distinct pattern of disease emerged as our Paleolithic ancestors moved into new ecological niches (Desowitz 1980), their mobility, small population size and low density precluded infectious disease from being a factor in the evolution of these populations. Finally, it will be shown that while emerging diseases have been a characteristic of human adaptation, following the shift to primary food production, there was an acceleration of the trend.
The traditional Hobbesian view of the 4,000,000 years of the Paleolithic was of the gatherer-hunters who foraged for their livelihood. Hobbes describes our ancestors living in 'continual fear' with 'a danger of violent death' and a life that