Small-scale field testing of alpha-cypermethrin water-dispersible granules in comparison with the recommended wettable powder formulation for indoor residual spraying against malaria vectors in Benin.
Parasit Vectors
; 11(1): 508, 2018 Sep 12.
Article
em En
| MEDLINE
| ID: mdl-30208937
ABSTRACT
BACKGROUND:
Pyrethroids are the most common class of insecticide used worldwide for indoor residual spraying (IRS) against malaria vectors. Water-dispersible granules (WG) are a pyrethroid formulation to be applied after disintegration and dispersion in water with less risks of inhalation than using the usual wettable powder (WP) formulation. The objective of this small-scale field study was to evaluate efficacy and duration of insecticidal action of a new alpha-cypermethrin WG (250 g a.i./kg) against susceptible Anopheles gambiae in comparison with the WHO reference product (alpha-cypermethrin WP, 50 g a.i./kg) on the most common indoor surfaces in Benin.METHODS:
Both formulations were applied at two target-dose concentrations in houses made of mud and cement in the Tokoli village in southern Benin. We measured the applied dose of insecticide by chemical analysis of filter paper samples collected from the sprayed inner walls. We recorded An. gambiae mortality and knock-down rates every 15 days during 6 months using standard WHO bioassays.RESULTS:
The alpha-cypermethrin WG formulation did not last as long as the WP formulation on both surfaces. The difference is higher with the 30 mg/m2 concentration for which the WP formulation reached the 80% mortality threshold during 2 months on the mud-plastered walls (3 months on cement) whereas the WG formulation last only one month (2 months on cement).CONCLUSIONS:
The new WG formulation has a shorter efficacy than the WHO recommended WP formulation. In this trial, both the WG and WP formulations had low durations of efficacy that would need at least two rounds of spray to cover the entire transmission season.Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Piretrinas
/
Controle de Mosquitos
/
Mosquitos Vetores
/
Inseticidas
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Malária
/
Anopheles
Limite:
Animals
Idioma:
En
Revista:
Parasit Vectors
Ano de publicação:
2018
Tipo de documento:
Article
País de afiliação:
Burquina Fasso