Introducing the TrypanoGEN biobank: A valuable resource for the elimination of human African trypanosomiasis

BackgroundHuman African trypanosomiasis (HAT), or sleeping sickness, is a disease caused by 2 subspecies of the protozoan parasite, Trypanosoma brucei (T.b.): T. b. gambiense and T. b. rhodesiense.T. b. gambiense causes the chronic form of sleeping sickness in West and Central Africa, and it is responsible for 98% of all reported cases [1].T. b. rhodesiense causes an acute, rapidly progressive infection in Eastern and Southern Africa.Over the last decade, control measures have reduced HAT incidence to less than 3,000 reported cases in 2015, the lowest level in 75 years [2].The target of the World Health Organization (WHO) is the elimination of the disease as a public health problem by 2020 and interruption of its transmission by 2030 [1].HAT has been considered as an invariably fatal disease.However, recent studies indicate that this is not the case [3][4][5].Infection by T. b. gambiense can result in a wide range of clinical outcomes in its human host [3][4][5].This has been illustrated by the descriptions of self-cure in HAT patients refusing treatment in Ivory Coast [6] and the report of a patient who developed sleeping sickness in the United Kingdom 29 years after he last left an endemic area [7].Furthermore, individuals with an elevated response to the card agglutination test for trypanosomiasis (CATT) and positive to the specific T.b. gambiense immune trypanolysis test, but who remain negative to available microscopic parasitological tests for more than 2 years, have been reported in West Africa and are believed to harbor latent infections [8,9].These observations suggest that individuals infected with T. b. gambiense may exhibit variable degrees of susceptibility, and some may be able to control the infection over long periods of time, as has also been demonstrated for African Animal Trypanosomiasis (AAT), caused by T. congolense [10,11].