title: Untangling the transmission dynamics of primary and secondary vectors of Trypanosoma cruzi in Colombia: parasite infection, feeding sources and discrete typing units.
abstract: Trypanosoma cruzi is the causative agent of Chagas disease. Due to its genetic diversity has been classified into six Discrete Typing Units (DTUs) in association with transmission cycles. In Colombia, natural T. cruzi infection has been detected in 15 triatomine species. There is scarce information regarding the infection rates, DTUs and feeding preferences of secondary vectors. Therefore, the aim of this study was to determine T. cruzi infection rates, parasite DTU, ecotopes, insect stages, geographical location and bug feeding preferences across six different triatomine species.
  
  
  
  A total of 245 insects were collected in seven departments of Colombia. We conducted molecular detection and genotyping of T. cruzi with subsequent identification of food sources. The frequency of infection, DTUs, TcI genotypes and feeding sources were plotted across the six species studied. A logistic regression model risk was estimated with insects positive for T. cruzi according to demographic and eco-epidemiological characteristics.
  
  
  
  We collected 85 specimens of Panstrongylus geniculatus, 77 Rhodnius prolixus, 37 R. pallescens, 34 Triatoma maculata, 8 R. pictipes and 4 T. dimidiata. The overall T. cruzi infection rate was 61.2% and presented statistical associations with the departments Meta (OR: 2.65; 95% CI: 1.69-4.17) and Guajira (OR: 2.13; 95% CI: 1.16-3.94); peridomestic ecotope (OR: 2.52: 95% CI: 1.62-3.93); the vector species P. geniculatus (OR: 2.40; 95% CI: 1.51-3.82) and T. maculata (OR: 2.09; 95% CI: 1.02-4.29); females (OR: 2.05; 95% CI: 1.39-3.04) and feeding on opossum (OR: 3.15; 95% CI: 1.85-11.69) and human blood (OR: 1.55; 95% CI: 1.07-2.24). Regarding the DTUs, we observed TcI (67.3%), TcII (6.7%), TcIII (8.7%), TcIV (4.0%) and TcV (6.0%). Across the samples typed as TcI, we detected TcIDom (19%) and sylvatic TcI (75%). The frequencies of feeding sources were 59.4% (human blood); 11.2% (hen); 9.6% (bat); 5.6% (opossum); 5.1% (mouse); 4.1% (dog); 3.0% (rodent); 1.0% (armadillo); and 1.0% (cow).
  
  
  
  New scenarios of T. cruzi transmission caused by secondary and sylvatic vectors are considered. The findings of sylvatic DTUs from bugs collected in domestic and peridomestic ecotopes confirms the emerging transmission scenarios in Colombia.
authors.affiliation: Grupo de Investigaciones Microbiológicas-UR (GIMUR), Programa de Biología, Facultad de Ciencias Naturales y Matemáticas, Universidad del Rosario, Bogotá, 111221, Colombia.|Estudiante Doctoral, Doctorado Ciencias biomédicas y biológicas, Universidad el Rosario, Bogotá, Colombia.
authors.forename: Carolina
authors.initials: C
authors.lastname: Hernández
authors.affiliation: Biology Program, Faculty of Natural Sciences and Mathematics, Universidad del Rosario, Carrera. 24 No. 63C-69, Bogotá, DC, 111221, Colombia.
authors.forename: Camilo
authors.initials: C
authors.lastname: Salazar
authors.affiliation: Facultad de Ciencias Agrarias, Universidad Nacional de Colombia, Bogotá, Colombia.
authors.forename: Helena
authors.initials: H
authors.lastname: Brochero
authors.affiliation: Grupo de Investigación COMPLEXUS, Fundación Universitaria Juan N. Corpas, Bogotá, Colombia.
authors.forename: Aníbal
authors.initials: A
authors.lastname: Teherán
authors.affiliation: Laboratorio de Salud Pública del Meta, Villavicencio, Colombia.
authors.forename: Luz Stella
authors.initials: LS
authors.lastname: Buitrago
authors.affiliation: Ministerio de Salud y protección Social, Bogotá, Colombia.
authors.forename: Mauricio
authors.initials: M
authors.lastname: Vera
authors.affiliation: Laboratorio de Salud Pública del Cesar, Valledupar, Colombia.
authors.forename: Hugo
authors.initials: H
authors.lastname: Soto
authors.affiliation: Laboratorio de Salud Pública, Secretaría de Salud de La Guajira, La Guajira, Colombia.
authors.forename: Zulibeth
authors.initials: Z
authors.lastname: Florez-Rivadeneira
authors.affiliation: Grupo de Entomología, Instituto Nacional de Salud, Bogotá, Colombia.
authors.forename: Sussane
authors.initials: S
authors.lastname: Ardila
authors.affiliation: Centro de Investigación en Salud para el Trópico, Universidad Cooperativa de Colombia, Santa Marta, Colombia.
authors.forename: Gabriel
authors.initials: G
authors.lastname: Parra-Henao
authors.affiliation: Grupo de Investigaciones Microbiológicas-UR (GIMUR), Programa de Biología, Facultad de Ciencias Naturales y Matemáticas, Universidad del Rosario, Bogotá, 111221, Colombia. juand.ramirez@urosario.edu.co.
authors.forename: Juan David
authors.initials: JD
authors.lastname: Ramírez
mesh_terms: D000818:Animals; D014355:Chagas Disease / Q000469:parasitology* / Q000635:transmission; D003105:Colombia; D018562:Disease Transmission, Infectious; D004199:Disease Vectors; D005838:Genotype; D006801:Humans; D015995:Prevalence; D014225:Triatominae / Q000469:parasitology*; D014349:Trypanosoma cruzi / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification*
keywords: Chagas disease; Colombia; DTUs; Feeding sources; Secondary vectors; Trypanosoma cruzi