BACKGROUND : Trypanosoma (Duttonella) vivax is a major pathogen of livestock in Africa and South America (SA),
and genetic studies limited to small sampling suggest greater diversity in East Africa (EA) compared to both West
Africa (WA) and SA.
METHODS : Multidimensional scaling and phylogenetic analyses of 112 sequences of the glycosomal glyceraldehyde
phosphate dehydrogenase (gGAPDH) gene and 263 sequences of the internal transcribed spacer of rDNA
(ITS rDNA) were performed to compare trypanosomes from tsetse flies from Gorongosa National Park and
Niassa National Reserve of Mozambique (MZ), wild ungulates and livestock from EA, and livestock isolates from WA
RESULTS : Multidimensional scaling (MDS) supported Tvv (T. vivax) and TvL (T. vivax-like) evolutionary lineages:
1) Tvv comprises two main groups, TvvA/B (all SA and WA isolates plus some isolates from EA) and TvvC/D (exclusively
from EA). The network revealed five ITS-genotypes within Tvv: Tvv1 (WA/EA isolates), Tvv2 (SA) and Tvv3–5 (EA).
EA genotypes of Tvv ranged from highly related to largely different from WA/SA genotypes. 2) TvL comprises two
gGAPDH-groups formed exclusively by EA sequences, TvLA (Tanzania/Kenya) and TvLB-D (MZ). This lineage contains
more than 11 ITS-genotypes, seven forming the lineage TvL-Gorongosa that diverged from T. vivax Y486 enough
to be identified as another species of the subgenus Duttonella. While gGAPDH sequences were fundamental
for classification at the subgenus, major evolutionary lineages and species levels, ITS rDNA sequences permitted
identification of known and novel genotypes.
CONCLUSIONS : Our results corroborate a remarkable diversity of Duttonella trypanosomes in EA, especially in wildlife
conservation areas, compared to the moderate diversity in WA. Surveys in wilderness areas in WA may reveal greater
diversity. Biogeographical and phylogenetic data point to EA as the place of origin, diversification and spread of
Duttonella trypanosomes across Africa, providing relevant insights towards the understanding of T. vivax evolutionary