European Conquest and the Spread of Disease – A Biological Weapon.

While Europe suffers as the latest epicenter of COVID-19 - a disease imported from Asia - in the past it was Europeans who brought with them diseases that infected and wiped out much of the native populations of the New World.

European Conquest and the Spread of Disease - A Biological Weapon.

In Latin America, Africa and and Pacific, entire cultures and people were almost wiped out by diseases brought to their shores by European colonisers and outsiders.

The Maya

The Maya Epidemics accidentally introduced by the Spanish included smallpox, measles and influenza. These diseases, together with typhus and yellow fever, had a major impact on Maya populations.

The Old World diseases brought with the Spanish and against which the indigenous New World peoples had no resistance were a deciding factor in the conquest of the Americas; they decimated populations before battles were even fought. It is estimated that 90% of the indigenous population had been eliminated by disease within the first century of European contact.

A single soldier arriving in Mexico in 1520 was carrying smallpox and initiated the devastating plagues that swept through the native populations. Maya written histories suggest that smallpox was rapidly transmitted throughout the Maya area the same year that it arrived in central Mexico. Modern knowledge of the impact of these diseases on populations with no prior exposure suggests that 33–50% of the population of the Maya highlands perished.

These diseases swept through Yucatan in the 1520s and 1530s, with periodic recurrences throughout the 16th century. By the late 16th century, malaria had arrived in the region, and yellow fever was first reported in the mid-17th century. Mortality was high, with approximately 50% of the population of some Yucatan Maya settlements being wiped out. Those areas of the peninsula that experience damper conditions became rapidly depopulated after the conquest with the introduction of malaria and other waterborne parasites. The native population of the northeastern portion of the peninsula was almost completely eliminated within fifty years of the conquest.

In the south, conditions conducive to the spread of malaria existed throughout Petén and Belize.In Tabasco the population of approximately 30,000 was reduced by an estimated 90%, with measles, smallpox, catarrhs, dysentery and fevers being the main culprits.At the time of the fall of Nojpetén in 1697, there are estimated to have been 60,000 Maya living around Lake Petén Itzá, including a large number of refugees from other areas. It is estimated that 88% of them died during the first ten years of colonial rule owing to a combination of disease and war.

Watch: Empire Builders: The Maya

Study Guide: The Maya

The Aztecs

The Aztecs in Tenochtitlan supposedly underwent a mass spread of smallpox from September to November of 1520.  Historians are unsure of how many of the Aztec people suffered and died from the disease at this time, but their newest tlatoani, Cuitláhuac, died from the disease.  This is important because the Aztecs lacked stable leadership during the Spanish conquest of Tenochtitlan, since their leaders (Moctezuma II and Cuitláhuac) died.  Regardless, the spread of smallpox throughout Tenochtitlan severely weakened the Aztec people and aided the Spanish in their final battle against the city.

On top of this, a native disease named Cocoliztli by the Aztecs led to millions of deaths. The disease returned several times, baffling native and Spanish doctors. Symptoms included high fever, black tongue, dark urine, dysentery, severe abdominal and chest pain, head and neck nodules, neurological disorders, jaundice, and profuse bleeding from the nose, eyes, and mouth. It usually killed within 3-4 days, leading to 5-15 million estimated deaths.

Read: Mexico: Conquistadors, Aztecs & Revolution

The Inca

The collapse of the Inca Empire started when the Spaniards arrived in Central America and transmitted their diseases to locals who spread them to other parts of the continent including South America. It is believed that in ten years between 50% and 90% of the population was attacked by these same diseases: smallpox, influenza, typhus, diphtheria, chicken pox and measles.

Disease spread alarmingly fast as Amerindians did not have the immunity to fight off newly brought viruses. They affected not only the working class but also the nobility. As a result disease weakened the working class which resulted in lower agricultural output as well as in the effectiveness of the communication network which were the backbone in the success of the empire.

Without its reliable communication network which used man power or chasquis, officials in Cusco, the capital, did not know what was happening as they were invaded in the north.

When the nobility got affected by disease it unraveled previously unseen struggle for power and a fight for the succession to the crown of Sapa Inca. This situation triggered a civil war between supporters of the two brothers Atahualpa and Huascar which enabled the Spaniards quick access to the control and the wealth of the empire

The reason disease spread after the Spanish arrival was because diseases were normally carried by herds of domestic animals such as sheep and pigs. In the Andes, there were no big herds of the indigenous llama. Eurasians carried the diseases but had developed immunity, but infected the indigenous people they had conquered who had not.

These “biological weapons” were in fact more effective than military conquest. 95 percent of the population of Native Americans through North and South America were to die an unpleasant death. Around 50 percent of the Inca died from the smallpox disease.

Read: Peru: Conquistadors, Incas, Inquisition

The Australian Aborigines

At the time of first European contact, many estimates have suggested between 315,000 and 750,000 people lived in Australia, in diverse groups, but upper estimates place the total population as high as 1.25 million.
A cumulative population of 1.6 billion people has been estimated to have lived in Australia over 65,000 years prior to British colonisation.
The regions of heaviest Aboriginal population were the same temperate coastal regions that are currently the most heavily populated. In the early 1900s it was commonly believed that the Aboriginal population of Australia was leading toward extinction. The population shrank from those present when colonisation began in New South Wales in 1788, to only 50,000 in 1930.
This drastic reduction in numbers has been attributed to outbreaks of smallpox and other diseases to which the Indigenous peoples had no immunity, but other sources have described the extent of frontier clashes and in some cases, deliberate killings of Aboriginal peoples.

Deadly infectious diseases like smallpox, influenza and tuberculosis were  major causes of Aboriginal deaths. Smallpox alone killed more than 50% of the Aboriginal population.

In April 1789, a major outbreak of smallpox killed large numbers of Indigenous Australians between Hawkesbury River, Broken Bay, and Port Hacking. Based on information recorded in the journals of some members of the First Fleet, the Aborigines of the Sydney region had never encountered the disease and lacked immunity to it. Unable to understand or counter the sickness, they often fled, leaving the sick with some food and water to fend for themselves. As the clans fled, the epidemic spread further along the coast and into the hinterland. This had a disastrous effect on Aboriginal society; with many of the productive hunters and gatherers dead, those who survived the initial outbreak began to starve.

Study Guide: Colonial Australia: The Gold Rush And Ned Kelly

The Pacific Islands

In 1826, almost 2,000 people lived on the Pacific island of Rapa-iti, but forty years later fewer than 120 survived; on Rapanui there were 3,000 people in 1862, yet within ten years only 175 were left. After centuries of relative isolation, these and other island communities had succumbed to diseases introduced by European explorers and traders.

There were many aspects to this “Ecological imperialism”. While some malaria was present in parts of Melanesia before the Spanish arrived, it became much more widely spread afterward; leprosy came later, except perhaps in Fiji and the Solomons; venereal disease was left behind whenever a ship landed; and, perhaps most devastating of all, explorers  spread tuberculosis throughout the islands.

Europeans also brought with them new animal parasites, including fleas, and bacterial, fungal, and viral infections, including Shigella, Herpes simplex, and hepatitis A. The gonococcus was still being introduced to some isolated islands in the 1930s.

There is no doubt that the introduction of foreign diseases including chickenpox, measles, the flu and venereal diseases had a disastrous impact in the Pacific Islands not just in the early contact period throughout the 19th century and early twentieth century. It contributed to a sudden and catastrophic decline in population accompanied by the abandonment of agricultural systems following the introduction of the European diseases.

The impacts of European and American colonisation on traditional society, governance and land tenure systems varied markedly across the region. In some islands, such as the atolls of Kiribati, much of the Solomon Islands, Papua New Guinea, and Vanuatu, traditional land tenure and land use practices continued through the colonial era and continue into the present alongside colonial plantation economies and extractive industries including mining and logging. In New Zealand, Hawaii and New Caledonia the arrival of large numbers of settlers disrupted traditional land tenure and issues of traditional rights to land are still being resolved.

In New Zealand the negotiation of traditional land rights is underpinned by the Treaty of Waitangi, signed in 1840 between Maori and the British Crown. In the Fiji Islands, traditional land tenure continued across most of the islands under British colonial policies aimed at protecting Indigenous people from the negative impacts of European colonisation witnessed elsewhere. However, the leasing of large areas of land for sugar plantations and the associated transport of indentured Indian labourers to work in the cane fields dramatically altered land use practices in the plantation areas along with the cultural, social and political profile of the nation as a whole.

Replacing traditional foods with imported, processed food has since contributed to the high prevalence of obesity and related health problems in the Pacific islands.

In at least 10 Pacific island countries, more than 50% (and in some, up to 90%) of the population is overweight according to World Health Organization (WHO) surveys. More seriously, obesity prevalence ranges from more than 30% in Fiji to a staggering 80% among women in American Samoa, a territory of the United States .Diabetes prevalence among adults in the Pacific region is among the highest in the world.

Read: Lisa Reihana: European explorers and the native people of the Pacific Islands

DVD: The Lost Story of Joseph Banks


Towards the end of the 19th century and early parts of the 20th century, and as more and more countries were colonized, Africans experienced an increase in famine and disease. Prior to colonialism, many African states had mastered their environment and the spread of diseases was relatively under control.

The agricultural skills they had acquired ensured that famines were never an issue and diseases could be controlled. Africans had cultural norms that placed a great deal of value on the environment and animal species. Early contact with European soldiers, traders and missionaries introduced diseases that devastated local African tribes.

In the 1880s, Italian traders introduced the cattle disease rinderpest which devastated areas in Tanzania, Kenya, Malawi, Zambia and South Africa in the early 1890s. Up to 90 percent of the cattle in parts of central and eastern Africa were killed by this disease. This devastation occurred at the same time that Europeans were colonizing Africa leaving them weak and unable to resist the early occupation by white settlers.

The introduction of the slave trade in East Africa produced new patterns of settlement; more people began to live in close proximity for security reasons. More people began living in close proximity and previously inhabited areas became large forests that were a breeding ground for tsetse flies especially in central and eastern Africa. As a result, some 200,000 people died of sleeping sickness around the Lake Victoria area. When the disease spread in the Congo, to Lake Tanganyika and eventually Zambia it had disastrous consequences for the local populations.

More contact with European slave traders and settlers led to the introduction of small pox and jiggers (a sand flea from South America which is painful and can lead to loss of limbs). In addition, Europeans also introduced cholera, yellow fever and meningitis. Some believe that these diseases were deliberately introduced by Europeans to make it easier to subdue the local people.

Arabs in Uganda were believed to have introduced sexually transmitted diseases including a particular strain of syphilis. Also, the introduction of gonorrhea in the equatorial region of Africa led to low birth rates in the early twentieth century.

Other more deliberate attempts in the effort to colonize Africa had very devastating effects on the land and people. Colonial warfare often involved scotched earth tactics which led to large scale destruction of villages and famines. In the German effort to suppress the Herero in Namibia for example, it is estimated that about 80,000 were killed and only 15,000 survived. As a consequence of the breakdown of traditional agricultural methods and economic systems, the regions of Ethiopia, Sudan and Kenya experienced famine in the 1880s and 1890s.

Ironically, Europeans viewed this process as necessary for civilizing Africans and hunger and disease became dominant stereotypes in the European mindset. African population dropped dramatically between the late 1800s and early 1900s. For example in the Belgian Congo, population dropped about 50 percent between 1880 and 1920. This left many Africans weak and vulnerable.

More information:

Read: Great Explorers: Africa

Read: Great Explorers: Pacific

Read: Great Explorers: The Americas

Read: The World’s Deadliest Plagues

Watch: Empire Builders – The British Empire

Watch: Empire Builders – The Spanish Empire

Study Guide: Epidemics Throughout The Ages

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