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?
- 5.6 million people live in areas at moderate to very high risk
- Fewer than 600 cases of the T.b. gambiense strain diagnosed in 2020, 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 (83% 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
- 70% of sleeping sickness cases in 2020 were reported in DRC
What are current treatments for sleeping sickness?
Pre-2009, treatments for stage-2 of the disease were toxic or difficult to administer. The arsenic derivative melarsoprol was developed in 1949. It is no longer used for gambiense sleeping sickness as it kills up to 5% of patients who receive it, but it remains the only drug available for advanced stage rhodesiense sleeping sickness.
In 2009, DNDi and partners launched NECT, the first new treatment for sleeping sickness in 25 years; however, it requires specialized hospital administration and trained staff.
At the end of 2018, fexinidazole, an all-oral 10-day treatment that we developed with our partners was recommended by the European Medicines Agency for treatment of both stages of gambiense sleeping sickness.
NECT has been provided free of charge in all 13 countries with recent sleeping sickness cases. The World Health Organization (WHO) provides NECT via drug donations by Sanofi and Bayer. From 2019 Sanofi will similarly donate supplies of fexinidazole.
What new treatments for sleeping sickness are needed?
WHO has set the target of eliminating sleeping sickness as a public health problem by 2020. 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 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?
- 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
- 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.
Last updated: August 2021
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