El uso de Sistemas de Información Geográfica - CDIA-EC ...

El uso de Sistemas de Información Geografica y Sensores Remotos (SR) en Salud Pública
Bogotá, Colombia, 27 al 30 de Marzo de 2006
prevalence of human infections in the same villages in Colombia. This provides a
quantitative comparison of the relative importance of the most common vector
species in the region.
The partial overlap between surveys allowed the serological results from
approximately 9,808 children to be linked to infestation prevalence at the village
level. Logistic regression was used to test the association between the probability
of each child being infected, and the proportion of houses in their village which had
sent pots with at least one triatomine of each species (R. prolixus, T. dimidiata.
Tests were carried out both univariately for each species, and multivariately (i.e.
estimates for the effect of each species control for the effect of all other species).
In all analyses, odds ratios were adjusted for the effect of age and sex of the child,
and for clustering at the village level.
Both univariate and multivariate analysis show a significant, and very large, positive
association between higher proportions of houses infested with R. prolixus and
higher probabilities of children being infected (Multivariate analysis Odds ratios for
infection in villages with 1-40% infestation 3.17 (95% CI 1.56-6.46), and for 41-
100% infestation 6.25 (2.07 – 18.91). There is little evidence for an association
with other vector species, and there is a suggestion of a negative effect of some
vector species.
The strong correlation with R. prolixus is expected, but the data presented here add
a direct epidemiological measurement of their importance. None of the other
species is usually considered as efficient a vector as R. prolixus, mainly because
they tend to be more abundant in the peridomestic rather than domestic
environment. It is surprising, however, to find no consistent evidence that infection
rates increase with higher levels of infestation of any of the other species. The
results should be treated with caution, both because the sample sizes for these
other species are smaller than for R. prolixus, and because these results appear to
contradict evidence for the vectorial importance of some other species (notably T.
dimidiata) in other locations. This should be further explored by detailed analysis of
these data, and potentially new studies in areas with single species and with mixed
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