Comparison of vigilance methods in three houses with different Triatoma infestans densities

Abstract

M arco T u lio G arcía-Zapata, D om ingos das V irgens and Philip Davis Marsden. Various vigilance methods were com paredfor 103 days in houses with different Triatoma infestans densities. The methods used were manual capture, capture by the inmates with plastic bag notijlcation, the Gomez Nuhez box, the Cohen trap, and pa-per sheets to detect faecal contamination and painted wall strips with a similar objective. I t was concluded thatplastic'bag notijication andpaper sheets are two methods o f longitudinal vigilance which could be useful in national controlprogrammes. Various vigilance methods exist which can be installed in bug infested houses, after the attack phase with residual insecticides, during a Chagas' control programme. We have already reported the use of a vigilance unit for individual householders3 which incorporates two effective vigilance methods namely the Gomez Nunez box and plastic bag notification by the householder. Unfortunately the Gomez Nunez trap is too complicated and expensive for use in routine control programmes. Since faeces are the most common sign of bug colonisation in the Gomez Nunez box we have evaluated the use of simple paper sheets tacked to the walls with favourable results1. In this paper we evaluate these methods with two further options, namely a strip of wall surface to detect recent faecal contamination and the use of the recently developed Cohen trap. M ATERIAL A N D M ETHODS