Human African trypanosomiasis, or sleeping sickness, is a parasitic infection found in sub-Saharan Africa, transmitted by the tsetse fly.
Generally known as sleeping sickness, human African trypanosomiasis is a parasitic infection transmitted by tsetse flies. Tsetse flies are found in 36 countries in sub-Saharan Africa, putting 65 million people at risk. The infection attacks the central nervous system, causing severe neurological disorders. Without treatment the disease is fatal.
According to the World Health Organization (WHO), more than 98 percent of reported cases are caused by the parasite Trypanosoma brucei gambiense, which is found in western and central Africa. The other 2 percent of cases are caused by Trypanosoma brucei rhodesiense, which is found in eastern and southern Africa. In 2013, 89 percent of all cases reported were in the Democratic Republic of Congo.
In 2013, 6,314 cases of sleeping sickness were recorded. However, the WHO believes this to be a fraction of the real number, with cases closer to 20,000 per year.
What Causes Sleeping Sickness?
The parasite causing sleeping sickness is transmitted to humans through infected tsetse flies, which breed in warm and humid areas. Inhabiting the vast savanna across sub-Saharan Africa, tsetse flies come into contact with people, cattle, and wild animals, all acting as reservoirs for the Trypanosoma parasites.
Symptoms of Sleeping Sickness
The first stage of sleeping sickness presents with non-specific symptoms such as fever, headache, weakness, itching, and joint pain. At this stage, sleeping sickness is easy to treat but difficult to diagnose. If no treatment is given, the parasite will invade the infected person’s central nervous system and the second stage sets in.
The second stage may be characterized by more specific symptoms, such as confusion, violent behavior, or convulsions. Named after one of its most striking symptoms, patients with sleeping sickness experience an inability to sleep during the night but are often overcome by sleep during the day.
Diagnosing Sleeping Sickness
Diagnosing sleeping sickness before the second stage of the disease is difficult due to the non-specific symptoms of the early stage.
Once the parasite is detected, a painful lumbar puncture must be made to examine the patient’s cerebro-spinal fluid.
This will determine the stage of the disease and the appropriate treatment.
Treating Sleeping Sickness
The type of treatment depends on the stage of the disease.
Drugs used in the first stage of the disease are of lower toxicity and are easier to administer. However, treatment success in the second stage of the disease depends on a drug that can cross the blood-brain barrier. Nifurtimox-eflornithine combination therapy, or NECT, is now the WHO's recommended course.
NECT is much safer than melarsoprol, the drug previously used to treat the disease. Developed in 1949, melarsoprol is often described by patients as ‘fire in the veins’; between five and 20 percent of those treated die of complications from the toxic drug. New molecules are currently under clinical trial in the hope of developing a safe, effective treatment for both stages of the disease that can be administered orally.
Doctors Without Borders/Médecins Sans Frontières (MSF) is currently responsible for the efficient supply and distribution of all sleeping sickness drugs used in the world today. Prevention efforts such as vector control are crucial to our efforts to keep sleeping sickness at bay. However, exhaustive screenings require a major investment in human and material resources.
MSF admitted 330 patients for sleeping sickness treatment in 2014.