Molecular diagnosis and phylogeographic analysis of Trypanosoma evansi in dogs (Canis lupus familiaris) suggest an epidemiological importance of this species in Colombia.

Surra disease is a zoonosis caused by Trypanosoma (Trypanozoon) evansi, a salivary trypanosome, originally from Africa, which affects a wide range of mammalian worldwide. Dogs are highly susceptible to T. evansi infection and they often exhibit strong clinical signs than can lead to death, even within weeks in untreated acute cases. The present survey is the first report through clinical, parasitological and molecular approaches, of two fatal cases of T. evansi in Colombian dogs. After analysing two presumptive cases of infection with Trypanosoma spp., in dogs by parasitological methods, we confirmed by molecular techniques the presence of T. evansi, finding clinical signs such as anaemia, thrombocytopenia and hepatosplenomegaly, with fatal outcomes within a week even after the treatment. A phylogenetic and phylogeographic analysis of both isolates from T. evansi, suggest a complex evolutionary relationship with species of Trypanozoon subgenus. Moreover, the haplotype H2 was observed for the first time in Colombia, in common areas where human cases of T. evansi infection has been reported. These findings imply a relevant problem for animal health in the country, and highlight the importance of this infection in domestic animals and the possibility of human cases.