African trypanosomiasis, also known as "sleeping sickness", is a parasitosis caused by flagellar protozoa of the genus Trypanosoma . The infection is transmitted by the bite of hematophagous dipterous insects belonging to the genus Glossina, better known as tse-tse flies . As can be understood from the name, the disease is present only in Africa, between the 15th parallel north and the 20th parallel south.
The Trypanosoma brucei species includes two subspecies - Trypanosoma brucei gambiense and Trypanosoma brucei rhodesiense - responsible, respectively, for two different forms of African trypanosomiasis, the rodesiense and the gambiense, which also have a different geographical location. Over 95% of the reported cases are attributable to the parasite T. brucei gambiense, widespread mainly in central and western Africa, while the other 5% is caused by T. brucei rhodesiense, present in the south-east of the continent.
Every year, about 10, 000 new cases of African trypanosomiasis are reported to the World Health Organization, but the suspicion is that this data is underestimated for failure to diagnose or notify.
