Trypanosoma brucei gambiense Group 2: The Unusual Suspect.

Trypanosoma brucei causes human African trypanosomiasis (HAT). Three subspecies were described: T. b. gambiense (Tbg) and T. b. rhodesiense (Tbr) in humans, and T. b. brucei (Tbb) in animals. Molecular markers subdivided Tbg into two groups: Tbg1 and Tbg2, of which the latter is different from Tbg1 and Tbr (absence of the SRA gene), but indistinguishable from Tbb. Tbg2 is considered to be a zoonotic form of HAT in West Africa. Tbg2 was found mainly in Côte d'Ivoire between 1978 and 1992, but the latest description was made in Ghana in 2013. New molecular tools would be welcome to characterize such infections and determine their origins (resistance to human serum or patient immunodeficiency) in the current context of HAT elimination.