title: Trypanosoma cruzi infection in Triatoma sordida before and after community-wide residual insecticide spraying in the Argentinean Chaco.
abstract: Triatoma sordida is a secondary vector of Trypanosoma cruzi in the Gran Chaco and Cerrado eco-regions where it frequently infests peridomestic and domestic habitats. In a well-defined area of the humid Argentine Chaco, very few T. sordida were found infected when examined by optical microscopic examination (OM). In order to further assess the role of T. sordida and the relative magnitude of subpatent bug infections, we examined the insects for T. cruzi infection, parasite Discrete Typing Units (DTUs) and bloodmeal sources using various molecular techniques. Among 205 bugs with a negative or no OM-based diagnosis, the prevalence of infection determined by kDNA-PCR was nearly the same in bugs captured before (6.3%) and 4 months after insecticide spraying (6.4%). On average, these estimates were sixfold higher than the prevalence of infection based on OM (1.1%). Only TcI was identified, a DTU typically associated with opossums and rodents. Chickens and turkeys were the only bloodmeal sources identified in the infected specimens and the main local hosts at the bugs' capture sites. As birds are refractory to T. cruzi infection, further studies are needed to identify the infectious bloodmeal hosts. The persistent finding of infected T. sordida after community-wide insecticide spraying highlights the need of sustained vector surveillance to effectively prevent T. cruzi transmission in the domestic and peridomestic habitats.
authors.affiliation: Laboratory of Eco-Epidemiology, Department of Ecology, Genetics and Evolution, Universidad de Buenos Aires-IEGEBA (CONICET-UBA), Buenos Aires, Argentina.
authors.forename: Natalia P
authors.initials: NP
authors.lastname: Macchiaverna
authors.affiliation: Laboratory of Eco-Epidemiology, Department of Ecology, Genetics and Evolution, Universidad de Buenos Aires-IEGEBA (CONICET-UBA), Buenos Aires, Argentina.
authors.forename: María S
authors.initials: MS
authors.lastname: Gaspe
authors.affiliation: Laboratory of Eco-Epidemiology, Department of Ecology, Genetics and Evolution, Universidad de Buenos Aires-IEGEBA (CONICET-UBA), Buenos Aires, Argentina.
authors.forename: Gustavo F
authors.initials: GF
authors.lastname: Enriquez
authors.affiliation: Dipartimento di Scienze Veterinarie, Università degli Studi di Torino, Grugliasco (TO), Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Tomassone
authors.affiliation: Laboratory of Eco-Epidemiology, Department of Ecology, Genetics and Evolution, Universidad de Buenos Aires-IEGEBA (CONICET-UBA), Buenos Aires, Argentina.
authors.forename: Ricardo E
authors.initials: RE
authors.lastname: Gürtler
authors.affiliation: Laboratory of Eco-Epidemiology, Department of Ecology, Genetics and Evolution, Universidad de Buenos Aires-IEGEBA (CONICET-UBA), Buenos Aires, Argentina. Electronic address: mvcardinal@ege.fcen.uba.ar.
authors.forename: Marta V
authors.initials: MV
authors.lastname: Cardinal
mesh_terms: D000818:Animals; D000829:Animals, Domestic; D001118:Argentina / Q000453:epidemiology; D014355:Chagas Disease / Q000453:epidemiology / Q000635:transmission*; D002645:Chickens; D018105:DNA, Kinetoplast / Q000235:genetics; D016054:DNA, Protozoan / Q000235:genetics; D007303:Insect Vectors / Q000469:parasitology*; D007306:Insecticides / Q000008:administration & dosage*; D016133:Polymerase Chain Reaction; D015995:Prevalence; D014224:Triatoma / Q000469:parasitology*; D014344:Trypanocidal Agents / Q000008:administration & dosage*; D014349:Trypanosoma cruzi / Q000502:physiology*; D014422:Turkeys
chemical_list: D018105:DNA, Kinetoplast; D016054:DNA, Protozoan; D007306:Insecticides; D014344:Trypanocidal Agents
keywords: Bloodmeal identification; DTU; Molecular diagnosis; Triatoma sordida; Trypanosoma cruzi; Vector control