Pyrethroid insecticide evaluation on different house structures in a Chagas disease endemic area of the Paraguayan Chaco


de Arias, AR; Lehane, MJ; Schofield, CJ; Maldonado, M; (2004) Pyrethroid insecticide evaluation on different house structures in a Chagas disease endemic area of the Paraguayan Chaco. Memorias do Instituto Oswaldo Cruz, 99 (6). p. 657. ISSN 0074-0276 DOI: https://doi.org/10.1590/S0074-02762004000600022

Full text not available from this repository.

Abstract

Insecticide effects of deltamethrin 2.5% SC (flowable solution) on different substrates and triatomine infestation rates in two indigenous villages (Estancia Salzar and Nueva Promesa) of the Paraguayan Chaco are reported. This field study was carried out to determine the extent to which variability in spray penetration may affect residual action of the insecticide. A total of 117 houses in the two villages were sprayed. Filter papers discs were placed on aluminium foil pinned to walls and roofs in selected houses and the applied insecticide concentration was determined by high pressure liquid chromatography (HPLC). The target dose rate was 25 mg a.i./m(2). The mean actual applied dose in Estancia Salazar was 11.2 +/- 3.1 mg a.i./m(2) in walls and 11.9 +/- 5.6 mg a.i./m(2) in roofs while in Nueva Promesa, where duplicates were carried out, the mean values were 19.9 +/- 6.9 mg a.i./m(2) and 34.7 +/- 10.4 mg a.i./m(2) in walls and 28.8 +/- 19.2 mg a.i./m(2) and 24.9 +/- 21.8 mg a.i./m(2) in roofs. This shows the unevenness and variability of applied doses during spraying campaigns, and also the reduced coverage over roof surfaces. However wall bioassays with Triatoma infestans nymphs in a 72 It exposure test showed that deposits of deltamethrin persisted in quantities sufficient to kill triatomines until three months post spraying. Knockdown by deltamethrin on both types of surfaces resulted in 100% final mortality. A lower insecticidal effect was observed on mud walls. However three months after treatment, sprayed lime-coated mud surfaces displayed a twofold greater capacity (57.5%) to kill triatomines than mud sprayed surfaces (25%). Re-infestation was detected by manual capture only in one locality, six months after spraying.

Item Type: Article
Keywords: Triatoma infestans, deltamethrin, pyrethroid, substrates, persistence, Triatoma-infestans, vector control
Faculty and Department: Faculty of Infectious and Tropical Diseases > Dept of Pathogen Molecular Biology
Web of Science ID: 224640300022
URI: http://researchonline.lshtm.ac.uk/id/eprint/14094

Statistics


Download activity - last 12 months
Downloads since deposit
0Downloads
292Hits
Accesses by country - last 12 months
Accesses by referrer - last 12 months
Impact and interest
Additional statistics for this record are available via IRStats2

Actions (login required)

Edit Item Edit Item