Colonialism and the Spread of Diseases: A Historical and Epidemiological Perspective

 

Colonial studies usually focus on socio-political and economic aspects of colonialism, but how colonialism affected the health and lives of colonial subjects remains understudied. The expansion of colonialism accelerated not only the movement of people and goods, but also pathogens, leading to exceptional epidemiological changes. In this article, I want to assess the relationship between colonialism and the spread of diseases in various colonies.

 

The Americas

When Europeans landed in America, they did not land alone. They also brought pathogens, unknown to the native American bodies. Diseases like smallpox, measles, and influenza not only severely affected local populations, but also caused demographic collapse. Some estimates place the decline of native populations at up to 90% after the arrival of Europeans. While the introduction of new pathogens may not have been the sole reason for the population collapse, other studies also mention inadequate nutrition, social conflicts, population displacement, and psychological stress connected with the arrival of foreigners. Some indigenous groups developed traditional healing methods and invented indigenous herbal medicines, but, unfortunately, these failed to protect them against the new pathogens.

 

Africa

In Africa, colonialism changed the disease pattern and landscape very significantly. Colonialists caused forced migration, introduced new agricultural practices, coerced people to stay in specific urban centers, and changed environments in ways that offered easy channels for the spread of diseases. Among various diseases was the Sleeping sickness, caused by deforestation and population displacement, increasing human contact with tsetse flies. According to Maryinez Lyons, due to Belgian colonial policies in the Congo, over half a million cases of the epidemic were recorded in the early 20th century.

 

Similarly, large Malaria outbreaks followed the construction of colonial infrastructure, such as the Congo-Ocean Railway. In "Death by Migration," Philip Curtin shows that even European colonizers themselves suffered high mortality rates in West Africa, with early settlements experiencing death rates exceeding 50% in their first year. While colonizers eventually developed preventive measures, such as quinine prophylaxis, they prioritized European lives over indigenous populations, reinforcing racial hierarchies in medical care.

Asia

Colonial India suffered a similar fate. Railways and canal projects by the British facilitated the spread of water-borne and parasitic infections. Recent studies associate six major cholera outbreaks from 1817 to 1920 in India with global trade, the accelerated rate of colonial expansion, inadequate urban planning, and poor housing and sanitation. The British introduced some health measures, but according to David Arnold, these efforts were made mainly to protect their own officials, not the subject populations.

 

The British authorities also launched some immunization campaigns against diseases like smallpox, but these proved inadequate and ineffective. Sanjoy Bhattacharya in "Expunging Variola" notes that these efforts were often coercive and insensitive, that led to widespread resistance among the masses, who, by refusing to be thus vaccinated, remained more vulnerable to such diseases. Rejecting traditional healing systems of Ayurveda and Unani medicine, which might have been effective in some cases, the British introduced their own medicine that caused more suspicion and mistrust among the local population.

 

Australia and New Zealand

In Australia, Aboriginal populations were not devastated in a single wave but were exposed to foreign pathogens and violence repeatedly over a long time. According to "Our Original Aggression," by Noel Butlin, the Aboriginal population witnessed a decline from 750,000 in 1788 to 31,000 in 1911 by disease, violence, and displacement. Similarly, Judy Campbell argues in "Invisible Invaders" that smallpox wiped out entire communities within months of European arrival.

 

The situation of the Māori in New Zealand was, however, slightly different from the Australian Aborigines. While their population declined by almost 50%, the impact of epidemics was less severe. Unlike their neighboring Aboriginal Australians, the Māori maintained some degree of political and social cohesion, which helped reduce some of the severest health impacts.

Intentional Disease Spread

In most cases, transmission of diseases during the colonial era was unintentional, but there is some evidence of intentional attempts to use the disease as a biological weapon. During Pontiac’s Rebellion (1763), some British officers are said to have distributed smallpox-infected blankets among the native Americans to weaken their resistance.

 

But, even if such intentional uses of diseases are debated, colonialism did negatively impact the subject populations by neglecting indigenous health care, using structural violence, and causing population displacement.

 

Colonial Public Health

Public health measures initiated by the colonial authorities were often the result of the desire to control local populations rather than improve their health. For example, in India, Europeans were often exempted from forced quarantines during the plague pandemic, whereas the Indians had no choice. Vaccine interventions were often accompanied by coercion and violence. Though these health measures may not be considered entirely exploitative, the recent scholarship suggests that these efforts were mainly influenced by racial prejudices and pragmatic concerns to maintain and strengthen their power.

Epidemics and Anti-Colonial Resistance

Diseases did not just devastate communities. Sometimes they also fueled resistance against colonial masters. While poverty, economic hardship, forced labor, and displacement pushed the subject populations to launch anti-colonial movements, the mismanagement of epidemics further alienated local populations accelerating demands for self-rule.

 

Legacies of Colonial Disease Transmission

Though colonialism has become the story of the past, the differential and negative impact of its policies persists. Since the colonial authorities did not invest enough in the public health infrastructure, most former colonies have not yet been able to improve their health systems even today. According to the WHO, Sub-Saharan Africa accounted for more than 90% of malaria and HIV/AIDs cases in 2020.

Conclusion

Whether intentional or not, the spread of diseases during colonialism altered the global disease landscape. While epidemics weakened local populations, and in some cases, wiped out entire villages, they also helped launch movements against the authorities. Colonial rule introduced modern medicine, but also reinforced racial prejudices and social hierarchies. Studying the past, we may work toward a more equitable health system.