Disease and epidemics in American Indian communities

SIGNIFICANCE: Within decades after contact with Europeans, Indigenous North American societies experienced rapid population declines. Although the reasons for this demographic collapse are complex, a prominent factor in that decline was the introduction of Old World infectious diseases by European explorers and settlers.

After the arrival of Europeans, the Indigenous population of North America began to decline. The Spanish intrusion, first into the Caribbean and then into the Southwest and Southeast circa 1520, launched a series of lethal epidemics that infected various Indigenous peoples. The epidemiological conquest of North America accelerated after the early seventeenth century, which saw English and French colonization along the Atlantic Seaboard. The dramatic population decline of Indigenous peoples continued until the early twentieth century. By 1920, the Indigenous American population of the United States was just 270,995, compared to an estimated 1.2 million to 18 million people who had inhabited North America at the time of the arrival of Europeans.

Increased mortality among Indigenous Americans as a result of introduced European diseases such as smallpox is attributable not to a lack of sufficient immunological response to infections in general but to the fact that the population had no prior exposure to these pathogens. The “new” pathogens, therefore, not only created a high degree of physiological stress but also engendered cultural stress. Epidemic episodes often resulted in a breakdown in the social system, elevating mortality levels.

Although European infectious diseases devastated many Indigenous societies, precontact North America was not a disease-free paradise. Biological and archaeological evidence documents the fact that precontact populations suffered from a number of afflictions, including malnutrition, anemia, and a variety of tuberculoid, trepanematoid, and other degenerative, chronic, and congenital conditions. This general state of health, combined with ecological and cultural factors, greatly affected the postcontact disease experience of Indigenous societies.

Sixteenth and Seventeenth Centuries

No Old World pathogen was more lethal than smallpox, which was unleashed in the Americas during the Spanish conquest. Starting in 1520, the disease spread throughout the Aztec Empire in what is now central Mexico, killing between one-quarter and one-half of the population within the first few years. Similar outbreaks swept through the Maya civilization in Central America, the Inca Empire in South America, and the Indigenous populations of Florida, wherever the conquistadors put ashore. Florida’s Timucua population, which may have once numbered more than 700,000, was down to just 150,000 by 1559 and still declining sharply.

Throughout the sixteenth century and into the seventeenth, twenty-three European infectious diseases appeared in North America, brought not just by the Spanish but by French, Dutch, and British explorers as well. Smallpox, measles, influenza, and the bubonic plague affected Indigenous populations largely east of the Mississippi and in the Southwest. European populations grew and expanded geographically as declining Indigenous populations relinquished their lands and resources. Those who resisted White encroachment were vanquished through genocidal warfare or relegated to mission life or reservations.

Eighteenth Century

By the eighteenth century, the European population had reached an estimated 223,000 people. Although Europeans were not the demographic majority, epidemics continued to pave the way for further colonization. Throughout the Atlantic coastal region and into the interior westward, Indigenous populations were decimated through genocidal warfare and diseases. In the southeastern region of North America, for example, the estimated Indigenous population in 1685 was 199,400. By 1970, the population was reduced to approximately 55,900—a decline of 71.9 percent.

In sum, European expansion during the first three centuries of colonization produced a demographic collapse of Indigenous North American populations. Introduced European infectious diseases, combined with periodic genocidal warfare and the destruction of lifeways, reduced the Indigenous population to approximately 600,000, while the European population grew to more than 5 million.

Nineteenth and Twentieth Centuries

During the nineteenth century, twenty-four epidemics affected Indigenous North Americans. Smallpox continued to appear every 7.9 years among some segments of the population. Between the smallpox episodes, Indigenous peoples contracted measles and cholera every 22.5 years. According to anthropologist Henry Dobyns, more epidemics occurred during the nineteenth century, with more frequency, than during any other.

One of the most devastating epidemics during this century was the 1837–38 smallpox epidemic. The disease diffused across most of North America, but the northern Plains region was hit especially hard. It is estimated that seventeen thousand of the northern Plains peoples died before the epidemic subsided. Such acute infectious diseases continued to plague Indigenous communities into the early reservation period. Only then did these infections give way to the twentieth-century epidemics of influenza, tuberculosis, and trachoma—chronic conditions that would plague Indigenous North Americans until the 1950s.

The placement of Indigenous North Americans on reservations or in rural communities did not mark the end of epidemics. Acute infectious diseases have been replaced by “diseases of poverty,” many of which reach epidemic proportions in some communities. Deaths from tuberculosis, type II diabetes mellitus, violence, suicide, accidents, and alcoholism among Indigenous Americans exceed the national average. In addition, Indigenous communities also had to contend with another epidemic: human immunodeficiency virus (HIV), which has made its presence disproportionately felt in some Indigenous communities.

Twenty-first Century

In the early twenty-first century, Indigenous communities also faced significant impacts from the COVID-19 pandemic. Many tribes experienced disproportionately high infection and mortality rates, driven by overcrowded housing, preexisting health disparities, limited access to healthcare, and historic underfunding of tribal health systems. At the same time, numerous Indigenous nations exercised their sovereignty to implement strong public health measures, including checkpoints, mask mandates, and vaccination campaigns, which in some areas proved more effective than surrounding state and local responses.

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