Research note: Sleeping sickness in colonial East and Central Africa

Romy van de Pol. Show Author details

Sleeping sickness commission catching tsetse
Sleeping Sickness Commission: catching tsetse

Sleeping sickness (or African trypanosomiases) is a disease caused by a parasite transmitted by the Tsetse Fly. The disease has been endemic to Africa for hundreds of years and over time communities learned how to avoid tsetse fly infested areas. To be sure, there were the occasional epidemics, but deaths due to sleeping sickness stayed relatively low. This equilibrium was deeply altered when European colonisers started invading the African continent. They contributed to a long sequence of sleeping sickness epidemics that afflicted East and Central Africa in the 20th century. How did these epidemics happen and which efforts did European scientists make to understand and get control over the disease? This blog post answers these questions summarizing the article by Headrick (2014).

Sleeping sickness came upon the European colonisers radar in the beginning of the 19th century, when a big epidemic broke out in East Africa. It cannot be said with certainty, but the author argues that the outbreak of the epidemic is probably related to the introduction of the rinderpest on the African continent with the Italian invasion of Eritrea in 1889. Rinderpest quickly became epizootic since cattle and wild animals had no resistance against it, therefore between 90-95% of them were killed. Because these animals disappeared, big pieces of land were suddenly uninhabited and nature started reconquering the land which made the Tsetse fly infested areas bigger. Also, cattle herders now had to hunt for their food thus being forced to enter these tsetse fly infested areas. Meanwhile an epidemic in French Congo and Ubangi-Shari (now the Central African Republic) broke out. The population there relied on canoe and waterways for transport because of the swampy area, an environment where Tsetse flies also thrive. These epidemics took a lot of lives and caused people to flee from their homes. 

Scientific missions

As a response to the epidemics, European colonisers decided to send renowned scientists to Africa to study the diseases. These visits to the tropics were at its peak between 1901 and 1913, with a total of fifteen medical research missions. The scientific missions soon started getting results, as the complex life of the trypanosome in the digestive track of the Tsetse fly was finally unravelled in 1909. In 1910, a second and more lethal variant that killed patients within months, instead of years, was discovered. Headrick argues that these scientific findings were possible because of international cooperation between the European researchers and physicians. This collaboration was partly fostered by major international congresses about sleeping sickness, which became popular during that time. To be sure, the research missions to Africa were also motivated by political reasons. For example, Portugal embarked on these missions to display how there were able to compete with England. 

There was also collaboration at a diplomatic level. Germany and England signed an agreement in 1908 to prevent border crossings by infected Africans and in 1911 they made an agreement to combat sleeping sickness in West Africa. However this cooperation came to a standstill when the First World War broke out in 1914. When the war ended it took years before efforts in cooperation resumed since the conflict caused substantial hostility between France and Germany. 

Despite the international cooperation between researchers and physicians, they were not able to develop effective treatments or preventive measures. Multiple medicines were developed, but none of them were able to reverse the course of the disease in the second phase, when the trypanosomes have entered the blood-brain barrier. Different types of medications were produced, although only atoxyl was commonly used, which was very toxic and caused partial to total blindness in 20% of patients. The chemotherapeutic dose was close to one, meaning that in order to get rid of the trypanosomes an amount close to a lethal dose had to be injected. Atoxyl was relatively cheap, useful in the tropics and easy to inject, therefore it was kept in use long after safer alternatives were developed. 

Ronald Ross and colleagues in a laboratory ca 1899

Different approaches to combat sleeping sickness from colonisers 

When the epidemic broke out in their colonies, European colonisers reacted quickly for multiple reasons. First, because of a humanitarian motive: “Saving the helpless Africans from this disease”. Second, there was an economic motivation as Africa (especially the equatorial zone) was already thinly populated, labour was needed for transport and agriculture, and cattle could not live in the tsetse fly infested areas. So, Headrick argues that the epidemic was a threat to workers and threat to economic prosperity. Finally, there was also a scientific motivation. Micro-biology was at its peak at the turn of the century and European scientists were extremely interested in identifying and understanding tropical diseases. 

Even though the European colonisers had similar motives, they had different approaches to combat sleeping sickness. Headrick highlights two distinct strategies. The first is the ‘environmental’ approach which focuses on physically separating humans from Tsetse flies. The second is the ‘medical’ approach that consists of attacking the trypanosomes to cure the sick and prevent the spread of pathogens to the healthy.  

The British chose an environmental approach in East Africa because of the advice of scientists. In 1906 the governor of Uganda ordered that everyone must move out of a two mile radius from the lake shores and islands of Lake Victoria because those areas were highly infected with Tsetse flies. It was also forbidden to go fishing, foraging or hunting in those regions. In addition, the governor set up isolation camps were the sick would be treated. Furthermore, efforts were made to destroy the breeding places of the flies and killing wildlife, which was believed to harbour the pathogen. However, some of these measures had a limited effect. For instance, Ugandans resisted forced displacement and controlling hunting practices was discussed but never enforced. In any case, the number of deaths due to sleeping sickness dropped substantially between 1905-1909 and by 1910 the epidemic had receded. 

In contrast to the British, the French applied a medical approach. Eugène Jamot made substantial efforts to set up a vertical health care system to treat sleeping sickness. There were mobile medical teams with the aim of eradicating trypanosomes from the entire population to reduce the risk of infecting the healthy. These teams visited villages and forced people to undergo examination and they injected patients with atoxyl. Whereas these measures had led to great resistance in German East Africa, and eventually the end to their sleeping sickness policy, the French were able to persist with their campaigns. 

The examinations done by the teams were not always humane. They often chose to inject everyone with atoxyl in highly affected areas, even if people did not present symptoms of suffering from sleeping sickness. Also, the teams used Atoxyl long after better and safer drugs had become available. Many tried to flee from these examinations by hiding in bushes when the medical teams approached. 


When European colonisers invaded the African continent they shattered the equilibrium between African communities and nature, creating a great sleeping sickness epidemic in the African continent. Each colonial power then responded differently to this public health challenge. 

The British followed the environmental approach, based on physically separating Africans from the Tsetse fly. The French, on the other hand, focused on eradicating the trypanosomes with atoxyl injections to prevent the healthy from getting infected. Both methods had their drawbacks and were based on coercion, therefore they were met with resistance by locals.

The success of (almost) eradicating sleeping sickness in 1940 put an end to the decline in the health of Africans in the preceding 50 years. After independence new epidemics broke out because of political unrest, civil disorder and population growth. Accurate and recent infection rates of sleeping sickness are hard to come by because of lack of sufficient information, so the struggle with the disease still continues. 

Further information:

  • The associated image of this post was taken from Wikimedia Commons (link).
  • This post is based on the following article: Headrick, D. R. (2014). Sleeping sickness epidemics and colonial responses in East and Central Africa, 1900–1940. PLoS neglected tropical diseases, 8(4), e2772.
  • This piece is based on research by Romy van de Pol during an internship at the Environmental and Economic History Group (Wageningen University).

Author details

Bachelor student (Wageningen University)