title: Peridomestic Infection as a Determining Factor of Dengue Transmission.
abstract: BACKGROUND
  The study of endemic dengue transmission is essential for proposing alternatives to impact its burden. The traditional paradigm establishes that transmission starts around cases, but there are few studies that determine the risk.
  
  
  METHODS
  To assess the association between the peridomestic dengue infection and the exposure to a dengue index case (IC), a cohort was carried out in two Mexican endemic communities. People cohabitating with IC or living within a 50-meter radius (exposed cohort) and subjects of areas with no ICs in a 200-meter radius (unexposed cohort) were included.
  
  
  RESULTS
  Exposure was associated with DENV infection in cohabitants (PRa 3.55; 95%CI 2.37-5.31) or neighbors (PRa 1.82; 95%CI 1.29-2.58). Age, location, toilets with no direct water discharge, families with children younger than 5 and the House Index, were associated with infection. Families with older than 13 were associated with a decreased frequency. After a month since the IC fever onset, the infection incidence was not influenced by exposure to an IC or vector density; it was influenced by the local seasonal behavior of dengue and the age. Additionally, we found asymptomatic infections accounted for 60% and a greater age was a protective factor for the presence of symptoms (RR 0.98; 95%CI 0.97-0.99).
  
  
  CONCLUSIONS
  The evidence suggests that dengue endemic transmission in these locations is initially peridomestic, around an infected subject who may be asymptomatic due to demographic structure and endemicity, and it is influenced by other characteristics of the individual, the neighborhood and the location. Once the transmission chain has been established, dengue spreads in the community probably by the adults who, despite being the group with lower infection frequency, mostly suffer asymptomatic infections and have higher mobility. This scenario complicates the opportunity and the effectiveness of control programs and highlights the need to apply multiple measures for dengue control.
authors.affiliation: Escuela de Medicina, Universidad de Santander, Bucaramanga, Santander, Colombia.|Centro de Investigaciones sobre Enfermedades Infecciosas, Instituto Nacional de Salud Pública, Cuernavaca, Morelos, México.|Organización Latinoamericana para el Fomento de la Investigación en Salud, Bucaramanga, Santander, Colombia.
authors.forename: Ruth Aralí
authors.initials: RA
authors.lastname: Martínez-Vega
authors.affiliation: Departamento de Control de Vectores, Instituto Nacional de Salud Pública, Tapachula, Chiapas, México.
authors.forename: Rogelio
authors.initials: R
authors.lastname: Danis-Lozano
authors.affiliation: Departamento de Epidemiologia, Universidade de São Paulo. São Paulo, São Paulo, Brazil.
authors.forename: Fredi Alexander
authors.initials: FA
authors.lastname: Díaz-Quijano
authors.affiliation: Universidad Nacional Autónoma de Mexico-Juriquilla, Santiago de Querétaro, Querétaro, México.
authors.forename: Jorge
authors.initials: J
authors.lastname: Velasco-Hernández
authors.affiliation: Subdirección de Geografía Médica y Sistemas, Instituto Nacional de Salud Pública, Cuernavaca, Morelos, México.
authors.forename: René
authors.initials: R
authors.lastname: Santos-Luna
authors.affiliation: Subdirección de Geografía Médica y Sistemas, Instituto Nacional de Salud Pública, Cuernavaca, Morelos, México.
authors.forename: Susana
authors.initials: S
authors.lastname: Román-Pérez
authors.affiliation: Facultad de Medicina, Universidad Nacional Autónoma de México, México D.F., México.
authors.forename: Pablo
authors.initials: P
authors.lastname: Kuri-Morales
authors.affiliation: Centro de Investigaciones sobre Enfermedades Infecciosas, Instituto Nacional de Salud Pública, Cuernavaca, Morelos, México.|Center for Tropical Diseases, University of Texas-Medical Branch, Galveston, Texas, United States of America.
authors.forename: José
authors.initials: J
authors.lastname: Ramos-Castañeda
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D058070:Asymptomatic Diseases; D002648:Child; D002675:Child, Preschool; D003715:Dengue / Q000453:epidemiology / Q000635:transmission*; D018562:Disease Transmission, Infectious; D019353:Endemic Diseases; D005191:Family Characteristics; D005260:Female; D006801:Humans; D008297:Male; D008800:Mexico / Q000453:epidemiology; D008875:Middle Aged; D011446:Prospective Studies; D055815:Young Adult