Threats to the effectiveness of insecticide-treated bednets for malaria control: thinking beyond insecticide resistance

From 2004 to 2019, insecticide-treated bednets (ITNs) have been the most effective tool for reducing malaria morbidity and mortality in sub-Saharan Africa. Recently, however, the decline in malaria cases and deaths has stalled. Some suggest that this inertia is due to increasing resistance in malaria vectors to the pyrethroid insecticides used for treating ITNs. However, there is presently little evidence to reach this conclusion and we therefore recommend that a broader perspective to evaluate ITN effectiveness in terms of access to nets, use of nets, bioefficacy, and durability should be taken. We argue that a single focus on insecticide resistance misses the bigger picture. To improve the effects of ITNs, net coverage should increase by increasing funding for programmes, adopting improved strategies for increasing ITN uptake, and enhancing the longevity of the active ingredients and the physical integrity of nets, while simultaneously accelerating the development and evaluation of novel vector control tools.

Automated summary

Insecticide-treated bednets (ITNs) have been effective in reducing malaria morbidity and mortality in sub-Saharan Africa from 2004 to 2019, but the decline in malaria cases and deaths has stalled recently. It is important to consider factors beyond insecticide resistance, such as access to nets, use of nets, bioefficacy, and durability, in evaluating the effectiveness of ITNs. To improve the impact of ITNs, efforts should focus on increasing net coverage, funding for programmes, strategies to increase ITN uptake, and developing novel vector control tools.