title: Origins of Chagas disease: Didelphis species are natural hosts of Trypanosoma cruzi I and armadillos hosts of Trypanosoma cruzi II, including hybrids.
abstract: Trypanosoma cruzi, the causative agent of Chagas disease, has at least two principal intraspecific subdivisions, T. cruzi I (TCI) and T. cruzi II (TCII), the latter containing up to five subgroups (a-e). Whilst it is known that TCI predominates from the Amazon basin northwards and TCII to the South, where the disease is considered to be clinically more severe, the precise clinical and evolutionary significance of these divisions remains enigmatic. Here, we present compelling evidence of an association between TCI and opossums (Didelphis), and TCII and armadillos, on the basis of key new findings from the Paraguayan Chaco region, together with a comprehensive analysis of historical data. We suggest that the distinct arboreal and terrestrial ecologies, respectively, of these mammal hosts provide a persuasive explanation for the extant T. cruzi intraspecific diversity in South America, and for separate origins of Chagas disease in northern South America and in the southern cone countries.
authors.affiliation: Department of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London, UK. matthew.yeo@lshtm.ac.uk
authors.forename: Matthew
authors.initials: M
authors.lastname: Yeo
authors.forename: Nidia
authors.initials: N
authors.lastname: Acosta
authors.forename: Martin
authors.initials: M
authors.lastname: Llewellyn
authors.forename: Humberto
authors.initials: H
authors.lastname: Sánchez
authors.forename: Susie
authors.initials: S
authors.lastname: Adamson
authors.forename: Graham A J
authors.initials: GA
authors.lastname: Miles
authors.forename: Elsa
authors.initials: E
authors.lastname: López
authors.forename: Nilsa
authors.initials: N
authors.lastname: González
authors.forename: James S
authors.initials: JS
authors.lastname: Patterson
authors.forename: Michael W
authors.initials: MW
authors.lastname: Gaunt
authors.forename: Antonieta Rojas
authors.initials: AR
authors.lastname: de Arias
authors.forename: Michael A
authors.initials: MA
authors.lastname: Miles
mesh_terms: D000818:Animals; D001135:Armadillos / Q000469:parasitology*; D014355:Chagas Disease / Q000635:transmission*; D048293:Didelphis / Q000469:parasitology*; D004199:Disease Vectors; D019353:Endemic Diseases / Q000662:veterinary; D005838:Genotype; D006790:Host-Parasite Interactions; D006801:Humans; D007303:Insect Vectors / Q000469:parasitology; D010239:Paraguay; D014225:Triatominae / Q000469:parasitology; D014349:Trypanosoma cruzi / Q000302:isolation & purification* / Q000502:physiology