Human African trypanosomiasis, also known as sleeping sickness is a parasitic disease transmitted by the bite of the 'Glossina' insect, commonly known as the tsetse fly.
The disease affects mostly poor populations living in remote rural areas of Africa. Untreated, it is usually fatal. Travelers also risk becoming infected if they venture through regions where the insect is common. Generally, the disease is not found in urban areas, although some cases have been reported in suburban areas of big cities in some disease endemic countries.
In 1995, WHO Expert Committee estimated that 60 million people were at risk with an estimated 300 000 new cases per year in Africa, with fewer than 30,000 cases diagnosed and treated.
In 2004, the number of new reported cases fell to 17 616 and WHO considered in that due to increased control, estimated cumulative rate to be between 50 000 and 70 000 cases .
In 2009, the number of new cases reported dropped below 10 000 (9 878) for first time in 50 years and the estimated number of actual cases is currently 30 000. This trend has been maintained in 2010, with 7139 cases reported.