title: First evidence that parasite infecting apparent aparasitemic serological suspects in human African trypanosomiasis are Trypanosoma brucei gambiense and are similar to those found in patients.
abstract: Thanks to its sensitivity and its ease of use in the field, the card agglutination test for trypanosomiasis (CATT) is widely used for serological screening of Trypanosoma brucei gambiense human African trypanosomiasis (HAT). Positive subjects are then examined by microscopy to confirm the disease. However, the CATT exhibits false-positive results raising the question of whether CATT-positive subjects who are not confirmed by microscopic detection of trypanosomes (SERO) are truly exposed to T.b. gambiense infection. For this purpose, we applied microsatellite genotyping on DNA extracted from blood of both HAT confirmed patients and SERO subjects in Guinea and Côte d'Ivoire since microsatellite genotyping has proved useful for the study of T.b. gambiense genetic diversity. Problems of amplification failures raise the question of the sensitivity of microsatellite markers when applied on biological samples especially from SERO subjects for who low blood parasitaemia are suspected. Nevertheless, we have shown that the trypanosomes from SERO individuals that have been genotyped belong to T.b. gambiense group 1 and were identical to those found in HAT patients. These results constitute the first evidences that at least some SERO are indeed infected by T.b. gambiense group 1 and that they may constitute a human reservoir of parasite in HAT foci. Whether these individuals should undergo treatment remains an open question as long as their role in HAT transmission is unknown. Our results strongly recommend the follow-up of such subjects to improve control strategies.
authors.affiliation: UMR 177 IRD-CIRAD, Centre International de Recherche-Développement sur l'Elevage en zone Subhumide (CIRDES), 01 BP 454 Bobo-Dioulasso 01, Burkina Faso. jacqueskabore@yahoo.fr
authors.forename: Jacques
authors.initials: J
authors.lastname: Kaboré
authors.forename: Mathurin
authors.initials: M
authors.lastname: Koffi
authors.forename: Bruno
authors.initials: B
authors.lastname: Bucheton
authors.forename: Annette
authors.initials: A
authors.lastname: MacLeod
authors.forename: Craig
authors.initials: C
authors.lastname: Duffy
authors.forename: Hamidou
authors.initials: H
authors.lastname: Ilboudo
authors.forename: Mamadou
authors.initials: M
authors.lastname: Camara
authors.forename: Thierry
authors.initials: T
authors.lastname: De Meeûs
authors.forename: Adrien Marie Gaston
authors.initials: AM
authors.lastname: Belem
authors.forename: Vincent
authors.initials: V
authors.lastname: Jamonneau
mesh_terms: D007560:Cote d'Ivoire; D005188:False Negative Reactions; D005819:Genetic Markers; D005838:Genotype; D016701:Guinea; D006801:Humans; D018895:Microsatellite Repeats; D025202:Molecular Diagnostic Techniques; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D014347:Trypanosoma brucei gambiense / Q000235:genetics* / Q000302:isolation & purification; D014353:Trypanosomiasis, African / Q000097:blood / Q000469:parasitology*
chemical_list: D005819:Genetic Markers