African Trypanosomiasis, commonly known as sleeping sickness, is a parasitic disease endemic to sub-Saharan Africa. Transmitted through the bite of an infected tsetse fly, it poses significant health challenges in affected regions.
Causative Agents and Transmission
African Trypanosomiasis is caused by two subspecies of the protozoan parasite Trypanosoma brucei:
- Trypanosoma brucei gambiense: Predominant in West and Central Africa, responsible for a chronic form of the disease.
- Trypanosoma brucei rhodesiense: Found in East and Southern Africa, causing an acute, rapidly progressing illness.
Both subspecies are transmitted to humans through the bite of infected tsetse flies. These flies inhabit rural areas, particularly regions with dense vegetation near rivers and lakes. The parasites can also reside in animal reservoirs, including domestic cattle and wild game, complicating control efforts.
Symptoms and Disease Progression
The clinical presentation of African Trypanosomiasis occurs in two stages:
- Hemolymphatic Phase: Initial symptoms are nonspecific and may include fever, headaches, joint pains, itching, and lymphadenopathy. Infections with T.b. rhodesiense may present with a trypanosomal chancre at the bite site.
- Neurological Phase: As the parasites invade the central nervous system, neurological symptoms emerge, such as sleep disturbances (leading to the term “sleeping sickness”), confusion, sensory disturbances, and coordination issues. Without prompt treatment, the disease is typically fatal.
Diagnosis and Treatment
Early diagnosis is crucial and involves identifying the parasite in blood, lymph node aspirates, or cerebrospinal fluid. Serological tests can aid in detection, especially for T.b. gambiense.
Treatment varies based on the disease stage and the infecting subspecies:
- Early Stage: Pentamidine is commonly used for T.b. gambiense, while suramin is preferred for T.b. rhodesiense.
- Late Stage: When the central nervous system is involved, treatment options include melarsoprol or eflornithine. The World Health Organization has also recommended fexinidazole, an oral medication effective against both stages of T.b. gambiense infection.
Prevention and Control
Preventive measures focus on reducing contact with tsetse flies:
- Avoidance: Refrain from visiting known tsetse fly habitats during peak activity periods.
- Protective Clothing: Wear long-sleeved shirts and pants in neutral colors, as tsetse flies are attracted to bright and dark colors.
- Insect Repellents: Utilize repellents containing DEET to deter tsetse flies.
- Vector Control: Implement strategies such as insecticide-treated traps and clearing vegetation to reduce tsetse fly populations.
For travellers to endemic regions, it’s advisable to consult travel health clinics, like the Tropical Medical Bureau, for personalized advice and potential prophylactic measures. You can also learn more about bite avoidance in the linked article.
Recent Developments
In August 2024, a 57-year-old U.S. tourist contracted T.b. rhodesiense after visiting the Zambezi Valley in northern Zimbabwe. This case underscores the importance of awareness and preventive measures for travelers to endemic areas.
Ongoing research aims to develop better diagnostic tools and treatments, with the goal of eliminating sleeping sickness as a public health problem. Continued surveillance and control efforts are vital to prevent resurgence in affected regions.
Book Appointment
Most travellers to Africa should start their vaccines about 4 to 6 weeks before they leave Ireland. However those planning a longer visit, or where their planned trip is likely to bring them to more rural parts of Africa, should attend earlier to ensure that they have sufficient time to complete the vaccine courses.
Find your local TMB travel health clinic.