Sleeping sickness is a parasitic infection spread by tsetse flies. The flies are found in 36 countries across sub-Saharan Africa, putting millions at risk.
The infection attacks the central nervous system and causes severe neurological disorders. Without treatment, it is fatal. Early symptoms include fever, headache, weakness, itching and joint pain, which can make it difficult to spot. Later, patients develop confusion, violent behaviour changes and convulsions.
The disease is named after one of its most striking symptoms, where patients experience the inability to sleep at night while being overcome by sleep during the day.