Trypanosoma cruzi: typing of genotype (sub)lineages in megacolon samples from bolivian patients.

Visceral dystrophy, a clinical complication of Chagas' disease, is more frequent in southern cone countries in South America, where Trypanosoma cruzi II (TcII) lineage predominates in human infection. As this major TcII lineage is not homogeneous population and its (sub)lineages are not geographically distributed evenly, therefore, we investigated the possible relationship between parasite (sub)lineages in megacolon patients. We typified the T. cruzi lineages and (sub)lineages in megacolon samples from 18 patients using kDNA probes specific of lineage TcI, TcIIb, TcIId and TcIIe. The majority of the samples (16/18) were (sub)lineage TcIId positive. However, two samples were positive for (sub)lineage TcIIb. Two synthetic probes discriminated variants of lineage TcIId. Proportion of TcIId variants encountered were 6/16, 6/16 and 4/16, similar to the distribution of Chagasic populations in Bolivia. Our data suggest that there is no preferential tropism of one particular lineage or variant of T. cruzi II in megacolon pathology.