Infectious diseases experienced on Congo expeditions

By Janet Wilson

During the trips from 1896 to 1910 there are several records in the diaries noting illnesses of various members of the expedition. Some of these are physical injuries from falls and animal attacks but over 80 of them refer to infectious diseases. Although some specific diseases are mentioned many of these records describe the illnesses as ‘fever’ with details only of the symptoms. With current knowledge and scientific developments many of these diseases can be prevented today through vaccination or treated with antibiotics and other drugs we have available. However at the time of these trips it would not be possible to identify some of these diseases and treatments were not available. Care would consist of treating the symptoms that arose and hope that the body’s own defences would overcome the pathogen. In the diaries illnesses are commonly described as the person having a high temperature, vomiting and diarrhoea which then resulted in dehydration.  Dysentry is a word used in the diaries to describe these fevers and is a general term describing a gastro-intestinal infection which can be caused by a range of pathogens including bacteria and protozoa; organisms commonly found in water or soil [1].

As there are records of shortages of fresh water on the expeditions and having to drink from local rivers, it is likely that the organisms causing the dysentery are from the local water supply. These sources could contain bacteria such as typhoid and protozoal organisms, causing amoebic dysentery, giardiasis or cryptosporidium.  Vaccines are now available for diseases such as typhoid and most of these conditions are currently treated with antibiotics [2]. At the time of the expeditions these were not available so the treatment would have been to rest, prevent dehydration and try to reduce the high temperature.

Specific diseases mentioned in the diaries are tick fever, red water fever, black water fever, malaria, sleeping sickness.

Tick Fever

African tick bite fever is a disease caused by bacteria. People get infected by being bitten by a tick usually whilst walking through tall grass or bush and the entry of bacteria into the body through this route. Symptoms that typically develop within 1–2 weeks of infection include fever, headache, malaise, rash, nausea and vomiting. This infection can be rapidly progressive and fatal, the current treatment being the intravenous administration of the antibiotic tetracycline [3]. At the time of the expeditions the aim would have been to treat the symptoms and hope the fever would subside.

Red Water Fever

This is a protozoan parasite of the blood that causes a haemolytic disease known as Babesiosis. The disease was first documented in 1888 and was a serious illness for wild and domestic animals especially cattle.

Symptoms are characterized by irregular fevers, chills, headaches, general lethargy, pain and malaise and in severe cases, haemolytic anaemia, jaundice and respiratory failure. It is spread through the saliva of a tick when it bites. In many cases, patients spontaneously recover with more severe infections treated with antibiotics and quinine. As quinine was first used as a medicine in 1820 for Malaria it could have been used for this disease also [4].

Malaria / Black Water Fever

Malaria is an infection of the liver and red blood cells caused by bites from infected mosquitos. Symptoms include cycles of shaking, chills and fever with profuse sweating, anaemia and liver and spleen enlargement. Black water fever is a serious form of malaria resulting in kidney failure [2]. Quinine would have been the main treatment at the time of the expeditions

Sleeping sickness

This disease with the scientific name of trypanosomiasis is transmitted by the tsetse fly which is found only in rural Africa. A bite by this fly is often painful and can develop into a red sore, called a chancre. Fever, severe headaches, irritability, extreme fatigue, swollen lymph nodes, and aching muscles and joints are common symptoms of sleeping sickness. Progressive confusion, personality changes, and other neurologic problems occur after the infection has invaded the central nervous system. If left untreated, the illness becomes worse, and death will occur within months. Medical treatment of African trypanosomiasis should begin as soon as possible and is guided by the infected person’s laboratory results. Pentamidine, discovered in 1937, is the drug used currently [2]. At the time of the expeditions there would have been no treatment for this condition so again treatment of symptoms would have been the course of action taken.

As many drugs used today for these illnesses did not exist at the time of the expeditions it is surprising there were not more serious illnesses and deaths of expedition members from these diseases.

About the author

Dr. Janet Wilson - is a Registered Nurse who has many years of clinical nursing experience and since 2004 has worked in Higher Education. She has a doctorate in Nursing and an interest in the history of healthcare practices as well as local history .

References

1. Engelkirk P, Duben-Engelkirk J. (2020) Burtons Microbiology for the Health Sciences 11th Edition Lippincott Williams & Wilkins

2. Myint S., Kilvington S., Maggs A., Swann R. (2001) Medical Microbiology made memorable. Churchill Livingstone. Edinburgh

3. Centre for Disease Control (2020) CDC Yellow Book: Health Information for International Travel Oxford University Press

4. Peel P. (2020) The History of Quinine. Gunther Publishing