title: Trypanosoma cruzi diversity in the Gran Chaco: mixed infections and differential host distribution of TcV and TcVI.
abstract: The transmission cycles of Trypanosoma cruzi in the Gran Chaco are complex networks involving domestic and wild components, whose interrelationships are not well understood. Knowing the circuit of transmission of the different Discrete Typing Units (DTUs) of T. cruzi in the complex environment of the Chaco region is relevant to understanding how the different components (reservoirs, vectors, ecotopes) interact. In the present study we identified the DTUs infecting humans and dogs in two rural areas of the Gran Chaco in Argentina, using molecular methods which avoid parasite culture. Blood samples of humans and dogs were typified by PCR-DNA blotting and hybridization assays with five specific DNA probes (TcI, TcII, TcIII, TcV and TcVI). PCR analyses were performed on seropositive human and dog samples and showed the presence of T. cruzi DNA in 41.7% (98/235) and 53% (35/66) samples, respectively. The identification of infective DTUs was determined in 83.6% (82/98) and 91.4% (32/35) in human and dog samples, respectively. Single infections (36.7% - 36/98) and a previously not detected high proportion of mixed infections (47.9% - 47/98) were found. In a 15.3% (15/98) of samples the infecting DTU was not identified. Among the single infections TcV was the most prevalent DTU (30.6% - 30/98) in human samples; while TcVI (42.8% - 15/35) showed the highest prevalence in dog samples. TcV/TcVI was the most prevalent mixed infection in humans (32.6% - 32/98); and TcI/TcVI (14.3% - 5/35) in dogs. Significant associations between TcV with humans and TcVI with dogs were detected. For the first time, the presence of TcIII was detected in humans from this region. The occurrence of one human infected whit TcIII (a principally wild DTU) could be suggested the emergence of this, in domestic cycles in the Gran Chaco.
authors.affiliation: Unidad de Epidemiología Molecular, Instituto de Patología Experimental, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad Nacional de Salta, Argentina; Instituto de Patología Experimental-CONICET, Universidad Nacional de Salta, Argentina. Electronic address: mariamercedes.mr@gmail.com.
authors.forename: María M
authors.initials: MM
authors.lastname: Monje-Rumi
authors.affiliation: Unidad de Epidemiología Molecular, Instituto de Patología Experimental, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad Nacional de Salta, Argentina; Instituto de Patología Experimental-CONICET, Universidad Nacional de Salta, Argentina.
authors.forename: Cecilia Pérez
authors.initials: CP
authors.lastname: Brandán
authors.affiliation: Unidad de Epidemiología Molecular, Instituto de Patología Experimental, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad Nacional de Salta, Argentina; Instituto de Patología Experimental-CONICET, Universidad Nacional de Salta, Argentina.
authors.forename: Paula G
authors.initials: PG
authors.lastname: Ragone
authors.affiliation: Unidad de Epidemiología Molecular, Instituto de Patología Experimental, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad Nacional de Salta, Argentina; Instituto de Patología Experimental-CONICET, Universidad Nacional de Salta, Argentina.
authors.forename: Nicolás
authors.initials: N
authors.lastname: Tomasini
authors.affiliation: Unidad de Epidemiología Molecular, Instituto de Patología Experimental, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad Nacional de Salta, Argentina; Instituto de Patología Experimental-CONICET, Universidad Nacional de Salta, Argentina.
authors.forename: Juan J
authors.initials: JJ
authors.lastname: Lauthier
authors.affiliation: Unidad de Epidemiología Molecular, Instituto de Patología Experimental, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad Nacional de Salta, Argentina; Instituto de Patología Experimental-CONICET, Universidad Nacional de Salta, Argentina.
authors.forename: Anahí M
authors.initials: AM
authors.lastname: Alberti D'Amato
authors.affiliation: Instituto de Investigaciones en Enfermedades Tropicales, Sede Regional Orán, Universidad Nacional de Salta, Argentina; Cátedra de Química Biológica, Facultad de Ciencias de Naturales, Universidad Nacional de Salta, Argentina.
authors.forename: Rubén O
authors.initials: RO
authors.lastname: Cimino
authors.affiliation: Cátedra de Microbiología, Facultad de Ciencias de la Salud, Universidad Nacional de Salta, Argentina.
authors.forename: Viviana
authors.initials: V
authors.lastname: Orellana
authors.affiliation: Instituto de Patología Experimental-CONICET, Universidad Nacional de Salta, Argentina.
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Basombrío
authors.affiliation: Unidad de Epidemiología Molecular, Instituto de Patología Experimental, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad Nacional de Salta, Argentina; Instituto de Patología Experimental-CONICET, Universidad Nacional de Salta, Argentina.
authors.forename: Patricio
authors.initials: P
authors.lastname: Diosque
mesh_terms: D000293:Adolescent; D000328:Adult; D000818:Animals; D001118:Argentina; D014355:Chagas Disease / Q000097:blood / Q000235:genetics / Q000469:parasitology* / Q000662:veterinary*; D002648:Child; D060085:Coinfection; D003430:Cross-Sectional Studies; D016054:DNA, Protozoan / Q000235:genetics; D004283:Dog Diseases / Q000097:blood* / Q000469:parasitology; D004285:Dogs; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D012424:Rural Population; D014349:Trypanosoma cruzi / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D055815:Young Adult
chemical_list: D016054:DNA, Protozoan
keywords: Argentina; Domestic cycle; Hybridization; PCR; Prevalence