At the beginning of the 19th century, European countries were constantly affected by tropical diseases during the large-scale colonial expansion of Africa, and tropical diseases became an urgent problem to be solved in order to protect the health of the colonists.
The important changes in science in the second half of the 19th century provided a fundamental paradigm for the study of tropical diseases, and thus diverged
into a separate discipline – tropical medicine.
The prevalence of sleeping sickness in Uganda in the early 20th century made it a "new favorite" for the study of tropical medicine, a young discipline, for which the United Kingdom sent a special expedition to the local area to investigate.
With active expeditions and scientific research activities, Britain has made a breakthrough in the pathology of sleeping sickness pathogens, won the crown of scientific research in this field, and successfully promoted its scientific research results in the colonies, and achieved initial achievements in the field of sleeping sickness treatment.
Construction of Tropical Medicine
For a long time, the tropics were considered to be harmful to the health of Europeans, so they rarely set foot in those "beautiful and dangerous" areas.
However, in the 19th century, with the increasing frequency of European exploration and colonization activities in Africa, tropical diseases attracted the attention of mainstream society like a prominent science.
At first, the doctors who accompanied them focused on the climate, comparing the differences between the tropics and the regions where they lived, and some continued the "miasma" explanation.
It is believed that Africa's hot climate is more likely to cause "miasma" and disease breeding due to the decay of vegetables and animal carcasses, and that some people are associated with race.
The famous British surgeon James Johnson, in his 1821 book The Effect of Tropical Climate on the European Physique, explained that "every race has a specific climatic zone, and once left the exclusive climatic zone, it will irreversibly affect health, leading to disease and premature death".
Although the above two views seem to be reasonable, they are not universal.
Indigenous Africans do not have natural immunity to tropical diseases, and some diseases affect only indigenous populations.
In addition, some tropical diseases are not confined to tropical climate zones, as evidenced by the epidemics of cholera and plague in countries located in temperate climate zones.
As a result, until the early 19th century, there were still many theories about why tropical diseases had such a devastating impact on the health of Europeans.
The turning point came in the mid-to-late 19th century, when a revolution in science led to a whole new understanding of tropical diseases. The first is the formulation of the germ theory.
In the 60s of the 19th century, Pasteur's famous gooseneck bottle experiment convincingly proved the existence of bacteria for the first time, opening a precedent for the bacteriological theory, and then the German scientist Robert Koch standardized it on this basis and formed a systematic "bacterial theory".
Guided by this theory, scientists used light microscopes to observe a variety of bacteria such as Bacillus anthracis, Bacillus melioidosis, and diphtheria bacillus, which are believed to be the root cause of the disease.
Correspondingly, etiology has shifted from the analysis of macroscopic factors in the past to the exploration of the microscopic world. The second is the discovery of vectors and hosts during disease transmission.
A vector is a vector that physically transfers a pathogen, and a host is an incubator for a pathogen.
In response to the boom of microscopic pathological research, scientists have discovered that there are pathogens other than bacteria in human tissues - parasites.
Its peculiarity lies in the fact that it survives in different forms at different stages of its life cycle with the help of vectors (also known as intermediate hosts).
In 1878, while Patrick Manson was studying filariasis in Xiamen, he observed that filaria only form embryos in human blood.
After a series of conjectures and inferences, he identified the key role played by mosquitoes in their evolution, and finally proved that Culex mosquitoes are the vectors and intermediate hosts of filariasis.
Inspired by Manson, in 1897 British physician Ronald Ross proved that malaria was transmitted by a mosquito during his medical service in India.
At the end of the 19th century, sleeping sickness, one of the representatives of tropical diseases, appeared in many parts of West Africa, but this endemic epidemic received only occasional concern in Britain.
At that time, the British Medical Journal and The Lancet were the two major British medical journals, which mainly introduced and publicized the medical construction of the empire, such as publishing the examination results and promotion lists of doctors in the army, navy and Indian medical services, to highlight the social role of doctors in the service of the colonies.
But the medical care available in the colonies was often limited, and when some European colonial governors did not receive adequate medical relief overseas, they would return to London for medical consultations.
Other merchants and sailors were treated in the Seamen's Hospital Association and its affiliated hospitals, and the cross-regional movement of personnel between the colonies and the overlords took the form of tropical diseases more directly in the form of British soil, which gradually attracted people's attention.
Scientific expedition of the Royal Society in Uganda
The institutionalization of tropical medicine led colonial powers to use this young but groundbreaking discipline to satisfy their own colonial expansion intentions, and the disease-ridden Africa became a stage for them to shine.
In 1894, the Ugandan Protectorate was formally established, and the announcement of this decision not only directly highlighted the geographical importance of the Upper Nile Valley, but also helped Britain defuse the threat from France and Belgium and prevent them from eyeing it again.
Although the "external strife" was quelled, the "internal strife" continued to affect British rule in the region.
Britain continued to expand the Ugandan protectorate through treaties and military occupation, but such coercive actions caused resentment among indigenous peoples, and as a result, armed clashes often occurred.
It was not until the signing of the Uganda Agreement in 1900 that Britain developed a fixed pattern of governing Uganda, i.e., the use of the original hierarchy of the Buganda Kingdom to exercise informal control over the entire region, while guaranteeing that the colonial authorities appointed governors were superior to the indigenous kings.
However, an outbreak of sleeping sickness in Uganda the following year disrupted Britain's plans.
In order to stabilize the newly established colonial order and safeguard future economic interests, the British government made sleeping sickness a major concern, and the scientific community took the lead in responding.
In 1902, the Council of the Royal Society discussed the prevalence of sleeping sickness in Uganda.
This follows an international debate about the causes of sleeping sickness, which many tend to consider as a contagious disease given the rapidly spreading nature of the infection.
However, none of the above points is lacking the necessary factual data, so the Royal Society, in order to find out the true cause of sleeping sickness, called on Uganda to launch a special investigation into the disease that would "cause great trouble" to the United Kingdom.
At the same time, Uganda's chief executive, Hayes Sadler, also requested that "an expert from the London Medical School be sent to guide the study of local medical personnel".
The active promotion of these two forces has made tropical medicine a core tool in the scientific investigation of sleeping sickness in Uganda, and its influence has increased day by day with the publication of the results.
Driven by internal and external factors, on May 10, 1902, the Royal Society sent its first sleeping sickness expedition to Uganda, which included three experts, pathologist George Carmichael Lowe, bacteriologist Aldo Castellani, and epidemiologist Cuthbert Christie, with Lowe being the leader of the expedition.
The selection of this list was greatly influenced by Manson, the originator of tropical medicine in the United Kingdom, Lowe and Castellani were both students of Manson and both came from the London School of Hygiene and Tropical Medicine, and Christie was based in India for a long time as a medical staff with extensive overseas experience and experience.
In order to make the team more rewarding, the Royal Society divided the focus of the investigation according to each person's professional strengths before setting off.
Lowe was a well-known pathologist before the team set out, having discovered the heartworm in 1901, which was later confirmed to be the cause of elephantiasis in humans.
The selection of Pyro for the expedition stemmed from Manson's discovery of filarial worm transmission by mosquitoes in 1878 and his high suspicion that sleeping sickness was related to a filarial infection, so Lo's main task was to investigate whether there was a filarial worm that could cause the occurrence of sleeping sickness and its vector.
Castellani used his bacteriological expertise to specialize in the bacteriology of sleeping sickness - streptococcus.
Christie, who has an epidemiological background, went around Lake Victoria and collected blood samples from residents to find the areas where filaria and sleeping sickness first appeared, and carried out a series of epidemiological investigations.
When the second expedition was formed, Castellani of the first expedition remained in the sleeping sickness laboratory in Uganda and came to a near-definite conclusion that trypanosomes were the causative agent of sleeping sickness.
Before the second expedition arrived, Castellani was told to communicate with Bruce about sleeping sickness.
But when they arrived, Castellani, out of protection of his own discovery and wariness of others, did not let the work go as smoothly as expected.
In a letter to Mr. Foster, secretary of the Royal Society, Bruce complained that Castellani's attitude was "very bad" and that "there has been no action in the last two months, and I would like to be severely disciplined against him." ”
The second investigation of sleeping sickness under the leadership of Bruce subdivided the difficult points of sleeping sickness research into several small problems, put forward hypotheses, and then used experiments to verify the conjecture.
They collected a wealth of experimental samples and presented objective and convincing experimental data, which not only improved the understanding of diseases in the colonial countries, confirmed the superiority of Western civilization, but also made the British mainland rely on the power of science to find a cure as soon as possible.