Origins of Chagas disease: Didelphis species are natural hosts of Trypanosoma cruzi I and armadillos hosts of Trypanosoma cruzi II, including hybrids.
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.
Yeo
Matthew
M
Department of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London, UK. matthew.yeo@lshtm.ac.uk
Acosta
Nidia
N
Llewellyn
Martin
M
Sánchez
Humberto
H
Adamson
Susie
S
Miles
Graham A J
GA
López
Elsa
E
González
Nilsa
N
Patterson
James S
JS
Gaunt
Michael W
MW
de Arias
Antonieta Rojas
AR
Miles
Michael A
MA
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