title: Environmental Transmission of Typhoid Fever in an Urban Slum.
abstract: BACKGROUND
  Enteric fever due to Salmonella Typhi (typhoid fever) occurs in urban areas with poor sanitation. While direct fecal-oral transmission is thought to be the predominant mode of transmission, recent evidence suggests that indirect environmental transmission may also contribute to disease spread.
  
  
  METHODS
  Data from a population-based infectious disease surveillance system (28,000 individuals followed biweekly) were used to map the spatial pattern of typhoid fever in Kibera, an urban informal settlement in Nairobi Kenya, between 2010-2011. Spatial modeling was used to test whether variations in topography and accumulation of surface water explain the geographic patterns of risk.
  
  
  RESULTS
  Among children less than ten years of age, risk of typhoid fever was geographically heterogeneous across the study area (p = 0.016) and was positively associated with lower elevation, OR = 1.87, 95% CI (1.36-2.57), p <0.001. In contrast, the risk of typhoid fever did not vary geographically or with elevation among individuals more than ten years of age [corrected].
  
  
  CONCLUSIONS
  Our results provide evidence of indirect, environmental transmission of typhoid fever among children, a group with high exposure to fecal pathogens in the environment. Spatially targeting sanitation interventions may decrease enteric fever transmission.
authors.affiliation: University of Washington, School of Public Health and Community Medicine, Department of Epidemiology, Seattle, Washington, United States of America.
authors.forename: Adam
authors.initials: A
authors.lastname: Akullian
authors.affiliation: Kenya Medical Research Institute, Center for Global Health Research (KEMRI-CGHR), Kenya.
authors.forename: Eric
authors.initials: E
authors.lastname: Ng'eno
authors.affiliation: University of Washington, School of Public Health and Community Medicine, Department of Epidemiology, Seattle, Washington, United States of America.
authors.forename: Alastair I
authors.initials: AI
authors.lastname: Matheson
authors.affiliation: Division of Global Health Protection, Center for Global Health, Centers for Disease Control and Prevention-Kenya, Nairobi, Kenya.
authors.forename: Leonard
authors.initials: L
authors.lastname: Cosmas
authors.affiliation: Division of Global Health Protection, Center for Global Health, Centers for Disease Control and Prevention-Kenya, Nairobi, Kenya.
authors.forename: Daniel
authors.initials: D
authors.lastname: Macharia
authors.affiliation: Division of Global Health Protection, Center for Global Health, Centers for Disease Control and Prevention-Kenya, Nairobi, Kenya.
authors.forename: Barry
authors.initials: B
authors.lastname: Fields
authors.affiliation: Kenya Medical Research Institute, Center for Global Health Research (KEMRI-CGHR), Kenya.
authors.forename: Godfrey
authors.initials: G
authors.lastname: Bigogo
authors.affiliation: Kenya Medical Research Institute, Center for Global Health Research (KEMRI-CGHR), Kenya.
authors.forename: Maina
authors.initials: M
authors.lastname: Mugoh
authors.affiliation: Departments of Global Health, Medicine, Pediatrics and Epidemiology, University of Washington, Seattle, Washington, United States of America.
authors.forename: Grace
authors.initials: G
authors.lastname: John-Stewart
authors.affiliation: Departments of Global Health, Medicine, Pediatrics and Epidemiology, University of Washington, Seattle, Washington, United States of America.
authors.forename: Judd L
authors.initials: JL
authors.lastname: Walson
authors.affiliation: University of Washington, Department of Statistics and Biostatistics, Seattle, Washington, United States of America.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Wakefield
authors.affiliation: Division of Global Health Protection, Center for Global Health, Centers for Disease Control and Prevention-Kenya, Nairobi, Kenya.
authors.forename: Joel M
authors.initials: JM
authors.lastname: Montgomery
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D018562:Disease Transmission, Infectious; D005260:Female; D005843:Geography; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007630:Kenya; D008297:Male; D008875:Middle Aged; D011204:Poverty Areas; D018570:Risk Assessment; D062206:Spatial Analysis; D014435:Typhoid Fever / Q000635:transmission*; D014505:Urban Population; D055815:Young Adult