[Spatial distribution of Ascaris lumbricoides infection].
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.
Campos
Mônica Rodrigues
MR
Instituto de Medicina Social, Universidade Estadual do Rio de Janeiro, Rio de Janeiro, RJ, Brasil.
Valencia
Luis Iván Ortiz
LI
Fortes
Bruno de Paula Menezes Drumond
Bde P
Braga
Ricardo Cerqueira Campos
RC
Medronho
Roberto de Andrade
Rde A
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