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
Presence of infestation at baseline, density of R. prolixus in outbuildings, availability
of hiding refuges (such as palm roofs and hen nests) and distance to the nearest
positive house, were major factors determining indoor infestation, colonization and
density of R. prolixus post-spraying. For T. maculata the presence of this vector at
baseline, the total number of hen nests indoors and the density of T. maculata in
peridomestic-outbuildings were the most important risk factors for indoor infestation,
colonization and density post spraying.
In peridomestic outbuildings the presence of nests and the presence of infestation
pre-spraying were the most important risk factors for the presence of triatomines
post-spraying. Additionally the distance to neighbouring outbuildings and the
presence of palm roofs in outbuildings were determinants of infestation colonization
and density.
Although there was a trend in effectiveness in favour of deltamethrin (as compared
with fenitrothion), no significant effect of insecticide type was detected on infestation,
colonization or density of R. prolixus in either houses or outbuildings one year after
spraying. In contrast, fenitrothion was found to be significantly more effective than
deltamethrin in reducing infestation, colonization and density of T. maculata both
indoors and in outbuildings.
The evidence provided by the trial appears to indicate that the effectiveness of
house spraying in Venezuela is significantly compromised by the frequent inability to
eliminate triatomines with a single spray round. Re-infestation of houses by
triatomines that have survived spraying in nearby outbuildings is also a serious
threat and there is also the possibility of re-invasion by R.prolixus from nearby
houses where spraying has not been fully effective. It seems unlikely that re-invasion
of houses by sylvatic R. prolixus bugs was the major cause of the infestations
detected in either houses or outbuildings within the first year after spraying. The trial
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