Table of Contents
ISRN Preventive Medicine
Volume 2013, Article ID 371934, 6 pages
Research Article

The Efficacy of Vectron 20 WP, Etofenprox, for Indoor Residual Spraying in Areas of High Vector Resistance to Pyrethroids and Organochlorines in Zambia

1National Malaria Control Centre, Ministry of Health, Directorate of Public Health and Research, P.O. Box 32509, Chainama College Grounds, 10101 Lusaka, Zambia
2Zambia Integrated Systems Strengthening Programme, Malaria Control Unit, Plot 1321 Enock Kavu Road, Rhodes Park, P.O. Box 39090, 10101 Lusaka, Zambia

Received 30 May 2012; Accepted 15 July 2012

Academic Editors: I. Adam, C. E. Cavasini, and A. Naheed

Copyright © 2013 Emmanuel Chanda et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


The selection of insecticide resistance in malaria vectors has the potential to compromise any insecticide-based vector control programme. To ensure that the insecticides used for indoor residual spraying and insecticide-treated nets in Zambia remain effective and their choice is evidence based, insecticide resistance surveillance and monitoring are essential. This study assessed and compared the residual efficacy of etofenprox (Vectron 20 WP), an ether pyrethroid, at 0.1 g/m2 with pyrethroids: bifenthrin (Bistar 10 WP) and lambda-cyhalothrin (Icon 10 CS) at 25 mg/m2 for indoor residual spraying. We also assessed the resistance status of etofenprox to local malaria vectors, An. funestus s.s and An. gambiae s.s, using World Health Organization standard protocols. The residual efficacy of Vectron 20 WP on cement, rendered walls of houses lasted for four months with 100% mortality. By the eighth month, the killing effect had reduced to 73.8% compared to 63.3% for bifenthrin and 77.0% for lambda-cyhalothrin. Susceptibility tests using standard World Health Organization assays on An. gambiae s.s showed susceptibility to etofenprox (0.1%) but some resistance was detected to Anopheles funestus s.s. The product is recommended as an ideal insecticide for indoor residual spraying for malaria control in Zambia as part of a resistance management programme in selected areas of the country.