title: Environmental change and infectious disease: how new roads affect the transmission of diarrheal pathogens in rural Ecuador.
abstract: Environmental change plays a large role in the emergence of infectious disease. The construction of a new road in a previously roadless area of northern coastal Ecuador provides a valuable natural experiment to examine how changes in the social and natural environment, mediated by road construction, affect the epidemiology of diarrheal diseases. Twenty-one villages were randomly selected to capture the full distribution of village population size and distance from a main road (remoteness), and these were compared with the major population center of the region, Borbón, that lies on the road. Estimates of enteric pathogen infection rates were obtained from case-control studies at the village level. Higher rates of infection were found in nonremote vs. remote villages [pathogenic Escherichia coli: odds ratio (OR) = 8.4, confidence interval (CI) 1.6, 43.5; rotavirus: OR = 4.0, CI 1.3, 12.1; and Giardia: OR = 1.9, CI 1.3, 2.7]. Higher rates of all-cause diarrhea were found in Borbón compared with the 21 villages (RR = 2.0, CI 1.5, 2.8), as well as when comparing nonremote and remote villages (OR = 2.7, CI 1.5, 4.8). Social network data collected in parallel offered a causal link between remoteness and disease. The significant and consistent trends across viral, bacterial, and protozoan pathogens suggest the importance of considering a broad range of pathogens with differing epidemiological patterns when assessing the environmental impact of new roads. This study provides insight into the initial health impacts that roads have on communities and into the social and environmental processes that create these impacts.
authors.affiliation: School of Public Health, University of Michigan, Ann Arbor, MI 48104, USA. jnse@umich.edu
authors.forename: Joseph N S
authors.initials: JN
authors.lastname: Eisenberg
authors.forename: William
authors.initials: W
authors.lastname: Cevallos
authors.forename: Karina
authors.initials: K
authors.lastname: Ponce
authors.forename: Karen
authors.initials: K
authors.lastname: Levy
authors.forename: Sarah J
authors.initials: SJ
authors.lastname: Bates
authors.forename: James C
authors.initials: JC
authors.lastname: Scott
authors.forename: Alan
authors.initials: A
authors.lastname: Hubbard
authors.forename: Nadia
authors.initials: N
authors.lastname: Vieira
authors.forename: Pablo
authors.initials: P
authors.lastname: Endara
authors.forename: Mauricio
authors.initials: M
authors.lastname: Espinel
authors.forename: Gabriel
authors.initials: G
authors.lastname: Trueba
authors.forename: Lee W
authors.initials: LW
authors.lastname: Riley
authors.forename: James
authors.initials: J
authors.lastname: Trostle
mesh_terms: D003967:Diarrhea / Q000453:epidemiology* / Q000382:microbiology / Q000469:parasitology / Q000821:virology; D004484:Ecuador / Q000453:epidemiology; D004777:Environment; D004927:Escherichia coli Infections / Q000453:epidemiology / Q000635:transmission*; D005243:Feces / Q000382:microbiology / Q000821:virology; D005873:Giardiasis / Q000453:epidemiology / Q000635:transmission*; D006801:Humans; D016133:Polymerase Chain Reaction; D012400:Rotavirus Infections / Q000453:epidemiology / Q000635:transmission*; D012424:Rural Population; D012931:Social Environment; D012939:Social Planning; D012959:Socioeconomic Factors; D014186:Transportation