Researchers from LSTM have confirmed that using pyrethroid-PBO treated nets to prevent malaria is more effective at killing mosquitoes in areas where there is a high level of resistance to pyrethroids.
The distribution of nets treated with pyrethroid insecticides has been very effective in reducing malaria transmission during the past two decades in Africa. However, there has been a rise in the number of mosquitoes developing resistance to pyrethroids, which is the only class of insecticides currently used to treat nets.
In a new Cochrane review, an independent team of review authors led by Katherine Gleave and Natalie Lissenden at LSTM assessed the efficacy of insecticide-treated nets (ITNs) with added piperonyl butoxide (PBO). This chemical works by blocking an enzyme in the mosquito that prevents pyrethroids from working, to overcome the problem of insecticide resistance.
LSTM’s Professor Hilary Ranson is senior author on the review. She said: “We have to find a way to maintain the efficacy of ITNs, which have been a cornerstone of vector control. While these nets are more expensive, the evidence shows that in areas where pyrethroid resistance is high, adding PBO to nets killed more mosquitoes, stopping them from feeding on people and probably reducing the levels of disease.”