Impact of insecticide resistance in Anopheles arabiensis on malaria incidence and prevalence in Sudan and the costs of mitigation

Significance Emerging insecticide resistance in malaria vectors could presage a catastrophic rebound in malaria morbidity and mortality. In areas of moderate levels of resistance to pyrethroids, long-lasting insecticidal nets (LLINs) and indoor residual spraying (IRS) with a carbamate insecticide were significantly more effective than IRS with pyrethroid insecticide. The impact on the effectiveness of LLINs could not be quantified. The incremental cost of using a carbamate insecticide to which vectors are susceptible was US $0.65 per person protected per year, which is considered acceptable by international standards. While the WHO recommends that different interventions, where possible, should use different insecticide classes, these data alone should not be used as the basis for a policy change in vector control interventions.