Lably
Skip to content

Native American disease and epidemics

  • 18 min read
  • 6 chapters

Related on Lably

Through Endemism, Pathogen and Gastrointestinal disease

Prior to 1492, endemic conditions in the Americas included localized parasites, treponema infections, Chagas disease, and regional gastrointestinal disease, none of which produced continent-wide epidemics. In contrast, European contact and the subsequent colonization of the Americas introduced acute, highly contagious pathogens such as smallpox, measles, typhus, and influenza, against which Indigenous populations possessed no prior immunological exposure.

While localized conditions were typically chronic, aggravating factors such as malnutrition, sudden changes in diet, physical exhaustion, stress, and physical displacement caused them to become far more lethal. Simultaneously, these same colonially-induced disruptions, compounded by the systemic and intentional destruction of communities, accelerated the rapid spread of Old World pathogens across Indigenous nations. An estimated population of 10 million Native Americans was reduced to 300,000 by 1900.

Background

The arrival and settlement of Europeans in the Americas resulted in what is known as the Columbian exchange. Europeans also took plants and goods back to the Old World. Potatoes and tomatoes from the Americas became integral to European and Asian cuisines, for instance.

But Europeans also unintentionally brought new infectious diseases. Most Old World diseases of known origin can be traced to Africa and Asia and were introduced to Europe over time. Smallpox originated in Africa or Asia, plague in Asia, cholera in Asia, influenza in Asia, malaria in Africa and Asia, measles from Asian rinderpest, tuberculosis in Asia, yellow fever in Africa, typhoid in Africa, herpes in Africa, zika in Africa, and mumps. A form of tuberculosis has also been identified in pre-Columbian South American populations, from bacterial genome sequences collected from human remains in Peru, and was probably transmitted to humans through seal hunting, but otherwise these Old-World diseases were transmitted to the Americas by European settlers, along with chickenpox, the common cold, diphtheria, scarlet fever, sexually transmitted diseases (with the possible exception of syphilis), typhus, and pertussis.

Each of these diseases resulted in sweeping epidemics among Native Americans, who sufered disability, illness, and a high mortality rate. The Europeans infected with such diseases typically carried them in a dormant state, were actively infected but asymptomatic, or had only mild symptoms, because Europe had been subject for centuries to a selective process by these diseases. The explorers and colonists often unknowingly passed the diseases to natives.

Although a variety of infectious diseases existed in the Americas in pre-Columbian times, the limited size of the populations, smaller number of domesticated animals with zoonotic diseases, and limited interactions between those populations (as compared to areas of Eurasia and Africa) hampered the transmission of communicable diseases.

One notable infectious disease that may be of American origin is syphilis, which originated in the Americas before 1492. However, a 2005 article entitled "History of Syphilis" states that this disease also originated from Africa. Another epidemic disease which is believed by modern-era experts to be indigenous was Cocoliztli, which is suspected to have been caused by climate change. Cocoliztli epidemics usually occurred within two years of a major drought. The epidemic in 1576 occurred after a drought stretching from Venezuela to Canada. Proponents of this epidemic's outbreak suggest the relationship between drought and outbreak which is reflected by the increased numbers of rodents carrying viral hemorrhagic fever during the rains that followed the drought. At least 12 epidemics are attributed to cocoliztli, with the largest occurring in 1545, 1576, 1736, and 1813. Soto et al. have hypothesized that a sizeable hemorrhagic fever outbreak could have contributed to the earlier collapse of the Classic Mayan civilization (AD 750–950). However, there are many theories that attempt to explain the decline of Mayan populations, none of them proven or taken as fact. Some experts believe other factors, such as over-use and eventual depletion of old-growth forests, and the loss of fertile soils caused by insufficiently conservative agricultural practices, played a larger role. The overall impact of those cultural practices on Mayan populations was exacerbated during naturally occurring, multiyear periods of drought that have been an oscillating feature of the local climate since long before the appearance of homo sapiens on the Yucatan peninsula.

The only disease which the Native Americans have historically shown high immunity against is scarlet fever.

Sign in to keep reading

5 more chapters are free with a Lably account.

More in Biology