title: Eco-epidemiological study of an endemic Chagas disease region in northern Colombia reveals the importance of Triatoma maculata (Hemiptera: Reduviidae), dogs and Didelphis marsupialis in Trypanosoma cruzi maintenance.
abstract: BACKGROUND
  In Colombia, Rhodnius prolixus and Triatoma dimidiata are the main domestic triatomine species known to transmit T. cruzi. However, there are multiple reports of T. cruzi transmission involving secondary vectors. In this work, we carried out an eco-epidemiological study on Margarita Island, located in the Caribbean region of Colombia, where Chagas disease is associated with non-domiciliated vectors.
  
  
  METHODS
  To understand the transmission dynamics of Trypanosoma cruzi in this area, we designed a comprehensive, multi-faceted study including the following: (i) entomological evaluation through a community-based insect-surveillance campaign, blood meal source determination and T. cruzi infection rate estimation in triatomine insects; (ii) serological determination of T. cruzi prevalence in children under 15 years old, as well as in domestic dogs and synanthropic mammals; (iii) evaluation of T. cruzi transmission capacity in dogs and Didelphis marsupialis, and (iv) genetic characterization of T. cruzi isolates targeting spliced-leader intergene region (SL-IR) genotypes.
  
  
  RESULTS
  Out of the 124 triatomines collected, 94% were Triatoma maculata, and 71.6% of them were infected with T. cruzi. Blood-meal source analysis showed that T. maculata feeds on multiple hosts, including humans and domestic dogs. Serological analysis indicated 2 of 803 children were infected, representing a prevalence of 0.25%. The prevalence in domestic dogs was 71.6% (171/224). Domestic dogs might not be competent reservoir hosts, as inferred from negative T. cruzi xenodiagnosis and haemoculture tests. However, 61.5% (8/13) of D. marsupialis, the most abundant synanthropic mammal captured, were T. cruzi-positive on xenodiagnosis and haemocultures.
  
  
  CONCLUSIONS
  This study reveals the role of peridomestic T. maculata and dogs in T. cruzi persistence in this region and presents evidence that D. marsupialis are a reservoir mediating peridomestic-zoonotic cycles. This picture reflects the complexity of the transmission dynamics of T. cruzi in an endemic area with non-domiciliated vectors where active human infection exists. There is an ongoing need to control peridomestic T. maculata populations and to implement continuous reservoir surveillance strategies with community participation.
authors.affiliation: Grupo BCEI, Universidad de Antioquia UdeA, Calle 70 No. 52-21, Medellin, Colombia. omarcantillo@gmail.com.
authors.forename: Omar
authors.initials: O
authors.lastname: Cantillo-Barraza
authors.affiliation: Grupo BCEI, Universidad de Antioquia UdeA, Calle 70 No. 52-21, Medellin, Colombia. edilsongarcesq@gmail.com.
authors.forename: Edilson
authors.initials: E
authors.lastname: Garcés
authors.affiliation: Grupo BCEI, Universidad de Antioquia UdeA, Calle 70 No. 52-21, Medellin, Colombia. amgomezpa@gmail.com.
authors.forename: Andrés
authors.initials: A
authors.lastname: Gómez-Palacio
authors.affiliation: Unidad de Entomología Médica, Secretaría de Salud del Departamento de Bolívar, Cartagena, Colombia. luisgonatodes@hotmail.com.
authors.forename: Luis A
authors.initials: LA
authors.lastname: Cortés
authors.affiliation: Laboratory of Trypanosomatid Biology, Oswaldo Cruz Institute, FIOCRUZ, Av. Brazil 4365, CEP 21040-360, Rio de Janeiro, RJ, Brazil. andre.pereira@ioc.fiocruz.br.
authors.forename: André
authors.initials: A
authors.lastname: Pereira
authors.affiliation: Centers for Disease Control and Prevention (CDC), Division of Parasitic Diseases and Malaria, Entomology Branch, Atlanta, GA, USA. pvm3@cdc.gov.
authors.forename: Paula L
authors.initials: PL
authors.lastname: Marcet
authors.affiliation: Laboratory of Trypanosomatid Biology, Oswaldo Cruz Institute, FIOCRUZ, Av. Brazil 4365, CEP 21040-360, Rio de Janeiro, RJ, Brazil. jansen@ioc.fiocruz.br.
authors.forename: Ana M
authors.initials: AM
authors.lastname: Jansen
authors.affiliation: Grupo BCEI, Universidad de Antioquia UdeA, Calle 70 No. 52-21, Medellin, Colombia. omar.triana@udea.edu.co.
authors.forename: Omar
authors.initials: O
authors.lastname: Triana-Chávez
mesh_terms: D000293:Adolescent; D000818:Animals; D017691:Caribbean Region / Q000453:epidemiology; D014355:Chagas Disease / Q000453:epidemiology* / Q000635:transmission / Q000662:veterinary; D002648:Child; D002675:Child, Preschool; D003105:Colombia / Q000453:epidemiology; D048293:Didelphis / Q000469:parasitology*; D004197:Disease Reservoirs; D018562:Disease Transmission, Infectious; D004285:Dogs / Q000469:parasitology*; D005838:Genotype; D006801:Humans; D007303:Insect Vectors; D016036:Seroepidemiologic Studies; D014224:Triatoma / Q000469:parasitology*; D014349:Trypanosoma cruzi / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*