Field testing and evaluation of insecticides for indoor residual spraying against Chagas vectors

Overview

 This document outlines the general procedures for field trials of residual insecticides against domestic Triatominae, where the aim is to eliminate the domestic bug populations and inhibit reinfestations. The procedure is suitable for village-scale field trials of a specified formulation applied at a single target dose rate, whose toxicological safety has already been approved. The procedure also allows for multiple village trials in order to compare the effects of different products, or different formulations of the same product, or different doses of the same formulation.

The basic procedure involves a pretrial entomological evaluation, followed by spraying and then a series of post-spray evaluations over a period of 12 months. Pre-and post-spray evaluations primarily involve manual capture of bugs infesting houses and peridomestic habitats, but post-spray evaluation also includes residue analysis and bioassays of residual activity on treated surfaces. Results are then expressed in terms of the proportion of houses apparently free of bugs over different periods of time post-spray, together with an estimation of the power of the residual product to inhibit any subsequent infestations.