title: Community-Based Entomological Surveillance Reveals Urban Foci of Chagas Disease Vectors in Sobral, State of Ceará, Northeastern Brazil.
abstract: BACKGROUND
  The aim of this work was to explore the potential risk of vector-borne Chagas disease in urban districts in northeastern Brazil, by analyzing the spatiotemporal distributions and natural infection rates with Trypanosoma cruzi of triatomine species captured in recent years. The main motivation of this work was an acute human case of Chagas disease reported in 2008 in the municipality of Sobral.
  
  
  RESULTS
  We analyzed data from community-based entomological surveillance carried out from 2010 to 2014. Triatomine natural T. cruzi infection was assessed by examination of insect feces by optical microscopy. Sites of triatomine capture were georeferenced through Google Earth and analyzed with ArcGIS. A total of 191 triatomines were collected, consisting of 82.2% Triatoma pseudomaculata, 7.9% Rhodnius nasutus, 5.8% T. brasiliensis, 3.7% Panstrongylus lutzi, and 0.5% P. megistus, with an overall natural infection index of 17.8%. Most infestations were reported in the districts of Dom José (36.2%), Padre Palhano (24.7%), and Alto do Cristo (10.6%). The overwhelming majority of insects (185/96.9%) were captured inside houses, and most insects tended to be collected in intermittent peaks. Moreover, captured triatomines tended to constitute colonies. The acute case reported in 2008 was found to be situated within a T. pseudomaculata hotspot.
  
  
  CONCLUSIONS
  The triatomine collection events carried out by dwellers were aggregated in time and space into distinct foci, suggesting that insects are intermittently and artificially introduced into the city, possibly via accidental migration from their natural reservoirs. The relatively high T. cruzi infection rate indicates considerable circulation of the parasite in these areas, increasing the risk of vector-borne Chagas disease infection. These data suggest a need to strengthen epidemiological surveillance and integrate appropriate control actions targeting triatomines, T. cruzi reservoirs, and human populations. Our data also identify Chagas disease transmission as a hazard in urban areas of Sobral.
authors.affiliation: Faculdade de Medicina, Universidade Federal do Ceará/Sobral, Sobral, Ceará, Brazil.
authors.forename: Cynara Carvalho
authors.initials: CC
authors.lastname: Parente
authors.affiliation: Faculdade de Farmácia, Odontologia e Enfermagem, Universidade Federal do Ceará, Fortaleza, Ceará, Brazil.
authors.forename: Fernando S M
authors.initials: FS
authors.lastname: Bezerra
authors.affiliation: Faculdade de Medicina, Universidade Federal do Ceará/Sobral, Sobral, Ceará, Brazil.
authors.forename: Plutarco I
authors.initials: PI
authors.lastname: Parente
authors.affiliation: Centro de Controle de Zoonoses, Secretaria Municipal de Saúde de Sobral, Sobral, Ceará, Brazil.
authors.forename: Raimundo V
authors.initials: RV
authors.lastname: Dias-Neto
authors.affiliation: Laboratório de Biologia de Tripanossomatídeos, Fundação Oswaldo Cruz, Fiocruz, Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Samanta C C
authors.initials: SC
authors.lastname: Xavier
authors.affiliation: Faculdade de Medicina, Universidade Federal do Ceará, Fortaleza, Ceará, Brazil.
authors.forename: Alberto N
authors.initials: AN
authors.lastname: Ramos
authors.affiliation: Laboratório de Epidemiologia e Sistemática Molecular, Instituto Oswaldo Cruz, Fiocruz, Rio de Janeiro, Brazil.|Escritório Técnico Regional Fiocruz, Teresina, Piauí, Brazil.
authors.forename: Filipe A
authors.initials: FA
authors.lastname: Carvalho-Costa
authors.affiliation: Laboratório de Ecoepidemiologia da Doença de Chagas, Instituto Oswaldo Cruz, Fiocruz, Rio de Janeiro, Brazil.
authors.forename: Marli M
authors.identifier: http://orcid.org/0000-0003-4424-8924
authors.initials: MM
authors.lastname: Lima
mesh_terms: D000818:Animals; D001938:Brazil / Q000453:epidemiology; D014355:Chagas Disease / Q000453:epidemiology / Q000469:parasitology* / Q000635:transmission*; D062665:Epidemiological Monitoring; D006801:Humans; D007303:Insect Vectors / Q000469:parasitology*; D010203:Panstrongylus / Q000469:parasitology; D012239:Rhodnius / Q000469:parasitology; D014224:Triatoma / Q000469:parasitology; D014225:Triatominae / Q000469:parasitology*; D014349:Trypanosoma cruzi; D014505:Urban Population