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Archived Comments for: Control of pyrethroid and DDT-resistant Anopheles gambiae by application of indoor residual spraying or mosquito nets treated with a long-lasting organophosphate insecticide, chlorpyrifos-methyl

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  1. New, effective insecticides against malaria vectors: a solid field test

    Edward Walker, Michigan State University

    3 March 2010

    The wonderful results of this nicely designed and summarized field study are balanced by the sobering conclusions, not found in the abstract but rather appearing at the end of the article.

    They are that industry has indeed been forthcoming with a highly promising and nearly immediately available insecticide formulation for control of malaria vectors through the indoor residual spray method, with demonstrated high efficacy against pyrethroid resistance populations. Yet, the manufacturer, for reasons unknown but perhaps related to product stewardship, out of concern of backlash from the public with regard to perceived health risks, or for some combination of reasons; does not intend to move the product into the vector control market, according to this paper's conclusions. On the one hand, their decision is understandable; and on the other, it runs counter to the prevailing philosophy of both the WHO and of organizations such as the Innovative Vector Control Consortium, which is to engage industry into registering their old and new products from agricultural and urban pest management uses to vector control uses (see M Zaim and P Guillet. 2002. Alternative insecticides: an urgent need. Trends in Parasitology 18:161-163; and Given the rise in pyrethroid resistance in field populations of malaria vectors, it does raise ethical and humanitarian concerns.

    Certainly a company cannot be forced to cross list its product registrations. But if the current model is to depend upon the private sector to be forthcoming with new and readily implemented tools; and that model falters as this scenario indicates, then what is the fallback plan? This commentator wholeheartedly agrees with the authors that: "The comparatively small size of the market and the unpredictability of winning tenders is a major deterrent to companies not already engaged in malaria control. The manufacturer should be encouraged by international donors and technical authorities to pursue further development and evaluation against malaria indicators in endemic settings where An. gambiae is pyrethroid-resistant or IRS is being considered for malaria control."

    Competing interests

    The commentator has no competing interests.