Sleeping sickness
Symptoms, transmission, and current treatments for sleeping sickness
Sleeping sickness
Symptoms, transmission, and current treatments for sleeping sickness
What is sleeping sickness?
Sleeping sickness, or human African trypanosomiasis, is a life-threatening disease caused by related parasite strains, Trypanosoma brucei gambiense and Trypanosoma brucei rhodesiense, transmitted by the tsetse fly.
People with early stage sleeping sickness often are not diagnosed. If not treated, the parasite crosses the blood-brain barrier and invades the central nervous system causing advanced stage sleeping sickness. During this stage, people develop neuropsychiatric symptoms such as sleep disruption, confusion, lethargy, and convulsions. If left untreated, sleeping sickness is usually fatal.
What is the impact of sleeping sickness?
- 1.5 million people with moderate to high risk of being infected
- 20% of infections are in children
- Fewer than 600 cases of the T.b. gambiense strain diagnosed in 2023, down from over 38,000 in 1998.
- Historically, deadly epidemics followed periods where disease seemed controlled
- Tsetse flies are present in 36 African countries
- gambiense sleeping sickness (96% of cases) has been reported in 15 countries in western and central Africa since 2000
- rhodesiense sleeping sickness has been reported in 7 countries in eastern and southern Africa since 2000
- 69% of sleeping sickness cases in 2023 were reported in DRC
What are current treatments for sleeping sickness?
For decades, treatment for sleeping sickness was complex, difficult to administer, and even toxic. The only treatment available was melarsoprol – a drug developed in the 1940s. Derived from arsenic, it was so toxic that it killed one in 20 patients.
In 2009, DNDi and partners introduced NECT, a safer combination treatment consisting of pills and 14 intravenous infusions. NECT was provided free of charge by the World Health Organization (WHO) in all 13 countries with recent sleeping sickness cases thanks to drug donations from Sanofi and Bayer.
However, NECT still required administration by trained staff in specialized hospitals, presenting serious challenges for patients and health systems in resource-constrained settings. DNDi continued efforts to develop simpler treatments with entirely new medicines that could be provided at the primary health care level.
At the end of 2018, the European Medicines Agency issued a positive scientific opinion on the use of fexinidazole for the treatment of both stages of T.b. gambiense sleeping sickness. Developed by DNDi and partners, the first ever all-oral treatment was soon approved for use in the Democratic Republic of the Congo and other affected countries. The simple oral cure is now provided free of charge by Sanofi to the WHO for distribution to all affected countries.
In 2023, the European Medicines Agency adopted a positive opinion of fexinidazole for the treatment of T.b. rhodesiense, a less common but acute form of sleeping sickness found in Eastern and Southern Africa.
What new treatments for sleeping sickness are needed?
WHO has set the target of eliminating sleeping sickness as a public health problem by 2020 and interruption of transmission (zero cases) by 2030. In order to maintain the current low levels of disease and reach the elimination target, a safe, effective, short-course oral treatment suitable for use in remote settings is needed.
What sleeping sickness treatments are we working on?
We aim to deliver new oral treatments to cure sleeping sickness to support the sustainable elimination of the disease. In addition to developing the first all-oral treatment for sleeping sickness, we are working on acoziborole, a new single-dose oral drug that could be a critical tool for sustainable elimination.
Find out about our work developing treatments for sleeping sickness
How do you get sleeping sickness?
- Insect bites: the parasites that cause sleeping sickness can be transmitted by the bite of infected tsetse flies
- Mother-to-child transmission
- Sexual contact
What are the symptoms of sleeping sickness?
Early Stage
- non-specific symptoms such as fever and weakness
- a person can be infected for months or even years without major signs or symptoms of the disease
Advanced Stage
- neurological and psychiatric symptoms such as confusion, lethargy, and convulsions
- if left untreated, usually fatal
How is sleeping sickness diagnosed?
Diagnosing sleeping sickness involves invasive tests to confirm a positive result by the rapid diagnostic tests used for community screening. Diagnosis requires confirming the presence of the parasite in any body fluid, usually in the blood and lymph system through a microscope. Painful lumbar punctures are used to detect the parasite in spinal fluid, which indicates the advanced stage of the disease.
The new treatment fexinidazole could potentially reduce the number of lumbar punctures because it can be used to treat both stages of gambiense sleeping sickness.
More information
Last updated: June 2024
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