title: Guns, germs and dogs: On the origin of Leishmania chagasi.
abstract: The evolutionary history of Leishmania chagasi, the aetiological agent of visceral leishmaniasis in South America has been widely debated. This study addresses the problem of the origin of L. chagasi, its timing and demography with fast evolving genetic markers, a suite of Bayesian clustering algorithms and coalescent modelling. Here, using 14 microsatellite markers, 450 strains from the Leishmania donovani complex, we show that the vast majority of the Central and South American L. chagasi were nested within the Portuguese Leishmania infantum clade. Moreover, L. chagasi allelic richness was half that of their Old World counterparts. The bottleneck signature was estimated to be about 500 years old and the settlement of L. chagasi in the New World, probably via infected dogs, was accompanied by a thousand-fold population decrease. Visceral leishmaniasis, lethal if untreated, is therefore one more disease that the Conquistadores brought to the New World.
authors.affiliation: Muséum National d'Histoire Naturelle, UMR-CNRS 7205, Laboratoire Origine Structure Evolution de la Biodiversité, 16 rue Buffon, F-75005 Paris, France.
authors.forename: Raphaël
authors.initials: R
authors.lastname: Leblois
authors.forename: Katrin
authors.initials: K
authors.lastname: Kuhls
authors.forename: Olivier
authors.initials: O
authors.lastname: François
authors.forename: Gabriele
authors.initials: G
authors.lastname: Schönian
authors.forename: Thierry
authors.initials: T
authors.lastname: Wirth
mesh_terms: D000818:Animals; D001499:Bayes Theorem; D002489:Central America / Q000453:epidemiology; D004285:Dogs; D019143:Evolution, Molecular; D006801:Humans; D007891:Leishmania / Q000235:genetics*; D007898:Leishmaniasis, Visceral / Q000453:epidemiology / Q000469:parasitology / Q000662:veterinary*; D018895:Microsatellite Repeats / Q000235:genetics; D010802:Phylogeny; D015203:Reproducibility of Results; D013020:South America / Q000453:epidemiology