title: [Spatial distribution of Ascaris lumbricoides infection].
abstract: OBJECTIVE
  To estimate risk areas for Ascaris lumbricoides parasitic overload, using geoprocessing and geostatistic methods of analysis.
  
  
  METHODS
  A coproparasitologic and domiciliary survey was conducted in 19 selected census districts of the state of Rio de Janeiro, Brazil. A sample of 1,664 children aged between 1 - 9 years was selected and plotted in their own home' centroid. Geostatistics techniques allowed spatial exploratory analysis, variographic study, and ordinary kriging. Student t-test, odds ratio and confidence intervals were used in the statistical analysis.
  
  
  RESULTS
  A prevalence of 27.5% was found for A. lumbricoides. Household income, housewife's education level and peridomiciliary conditions were identified as significantly associated factors to the occurrence of ascariasis. An isotropic spherical semivariogram model with 150-m reach, contribution of 0.45 and nugget effect of 0.55 was employed in ordinary kriging.
  
  
  CONCLUSIONS
  Peridomiciliary impact on ascariasis is confirmed by a spatial continuity of 150 m. Disease occurrence could be estimated in the study area and a risk map elaborated using ordinary kriging.
authors.affiliation: Instituto de Medicina Social, Universidade Estadual do Rio de Janeiro, Rio de Janeiro, RJ, Brasil.
authors.forename: Mônica Rodrigues
authors.initials: MR
authors.lastname: Campos
authors.forename: Luis Iván Ortiz
authors.initials: LI
authors.lastname: Valencia
authors.forename: Bruno de Paula Menezes Drumond
authors.initials: Bde P
authors.lastname: Fortes
authors.forename: Ricardo Cerqueira Campos
authors.initials: RC
authors.lastname: Braga
authors.forename: Roberto de Andrade
authors.initials: Rde A
authors.lastname: Medronho
mesh_terms: D000818:Animals; D001196:Ascariasis / Q000453:epidemiology* / Q000469:parasitology* / Q000635:transmission; D017164:Ascaris lumbricoides / Q000302:isolation & purification / Q000502:physiology*; D001938:Brazil / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D004522:Educational Status; D004777:Environment; D006801:Humans; D007223:Infant; D010270:Parasite Egg Count / Q000379:methods; D015995:Prevalence; D012111:Residence Characteristics; D018570:Risk Assessment; D012499:Sanitation; D012959:Socioeconomic Factors