The Present and the Past

Writing in 1963, A. Cockbura claimed that “tubercu­losis had not displaced malaria as the world’s num­ber one problem in infectious disease,” but like ma­laria, it has become rare and under control in Nearctica.

Like other so-called developed areas, North Amer­ica has undergone both demographic and epidemio­logical transitions (Omran 1977): from high birth and death rates to low birth and death rates, and from the predominance of infectious diseases in caus­ing death, to a preeminence of degenerative diseases (heart disease and cancers) in causing death (Dubos 1968). Genes replace “germs” as the significant vari­ables in these societies (Ward 1980). Having said that, one can question just how and when these transitions took place. Almost certainly they did not occur simultaneously for each of the three groups discussed here. The Amerindians survived an initial period of adjustment on entering the continent, when adaptation would bring great stress but infec­tions as such would be rare. They then grew in numbers and, with the development of agriculture and sedentary villages, attained densities that gave rise to self-contamination, in addition to the hazards of the field and hunt. However, as St. Hoyme (1969) observed, “At the time of the conquest, Indians suf­fered less from contagious diseases than from arthri­tis, nutritional and metabolic disturbances, and non­specific infections associated with traumata.”

At this point, the era of exotic contagions dawned, with death rates threatening extinction. This did not happen uniformly or necessarily (Meister 1976). Thus, some areas experienced rapid population de­cline, and others growth. Gradually white newcom­ers and, to a lesser extent, blacks, as well as Amerin­dians, all adjusted to the new disease environment, and populations recovered, only to encounter new hazards as a result of environmental moves from traditional homelands.

Today, however, most Amerindian groups con­tinue to have high infant mortality rates and high rates of infectious disease. The blacks, too, like the Amerindians prior to contact, were in a state of health homeostasis when rudely plucked from Af­rica and transported to the New World, with a terri­ble toll being paid en route (Pope-Hennessy 1967; Kiple 1984). Once in America they suffered a large number of infections that, according to William Postell (1951),

may have been caused by dietary deficiency. The great number of dental caries, sore eyes, sore mouths, sore feet and legs, and skin lesions is suggestive of pellagra... for it is suspected that the slave received an improperly bal­anced diet, particularly during the winter months [and] suffered greatly from cholera, pneumonia, dysentery... and probably to a lesser extent than his white master, from yellow fever and malaria.

Respiratory complaints or “pleuretical disorders” were particularly fatal to them (Duffy 1972). Since the days of slavery, conditions have improved for black Americans, but much more slowly than for the white segment of the population. Thus there are now fewer deaths from fevers and tuberculosis and infant mortality is declining, but both are still much higher among blacks than among white Americans (Bouv­ier and Van der Tak 1976). The result is that the national mortality rates for the United States for many ages and causes are inflated by inclusion of the relatively disadvantaged black minority, and the full impact of lower birth and death rates has not yet been seen for this group.

White Americans, like the blacks, experienced an initial seasoning period upon arriving in Nearctica. Thereafter they grew rapidly in numbers, experienc­ing more healthful conditions than those currently prevailing in Europe (Duffy 1972; Dobson 1987). They did, however, have higher mortality rates in the southern colonies and continually in the coastal towns into which disease was constantly brought from overseas. Thus, urban areas acted as reservoirs of infection that periodically broke out to cause sud­den devastation in the new generation of suscepti- bles in the smaller settlements and countryside (Dob­son 1987). Prophylactic measures, notably improved sanitation and standard of living, enabled this group to enjoy the full benefits of the transition model. Thus,

as a result of the ensuing rise in economic standards, diseases associated with toiling for food and coping with natural disasters have been supplanted by those which spring from the complexities of our technological age, in which man’s connection with the soil has become less direct. (Furness 1970)