In trials in Africa, bednets made of PYRETHROID and FIPRONIL showed improved entomological and epidemiological effects. This has led to increased demand for this new online course in malaria-endemic countries. PermaNet Dual is a new deltamethrin and clofenac mesh developed by Vestergaard Sàrl to provide additional capabilities to malaria control programmes. We conducted a pilot cockpit trial to evaluate the effectiveness of PermaNet Dual against wild, free-flying pyrethroid-resistant Anopheles gambiae mosquitoes in Cove, Benin. PermaNet Dual caused higher mosquito mortality if not washed compared to nets containing pyrethroid alone and nets containing pyrethroid and PIPERONYL BUTOXIDE (77% for PermaNet Dual, 23% for PermaNet 2.0 and 23% for PermaNet 3.0) 56% p < 0.001) after 20 years. standardized washes (75% for PermaNet Dual, 14% for PermaNet 2.0, 30% for PermaNet 3.0, p < 0.001). Using intermediate non-inferiority margins defined by the World Health Organization, PermaNet Dual was also non-inferior in carrier mortality to the pyrethroid-clofenazoline, which demonstrated improved public health value (Interceptor G2) (79% vs 76). %, OR = 0.878, 95% CI 0.719–1.073), but not for protection against blood supply (35% vs. 26%, OR = 1.424, 95% CI 1.177–1.723). PermaNet Dual is an additional option to this highly effective type of net to improve the control of malaria transmitted by pyrethroid-resistant mosquitoes.
Insecticide-treated bed nets (ITNs) are the most effective and widely used malaria prevention measure. They have been repeatedly shown to reduce malaria morbidity and mortality in trial and program conditions and have made the largest contribution of any recent intervention to reduce malaria incidence. However, their dependence on one class of insecticides (pyrethroids) exerts selective pressure, promoting the spread of pyrethroid resistance in malaria vectors. Between 2010 and 2020, pyrethroid resistance was detected in at least one vector species in 88% of malaria-endemic countries. Although studies have shown that insecticide-treated bednets protect against malaria despite resistance, there is strong evidence that mosquitoes exposed to pyrethroid-treated bednets have improved survival and feeding capacity. Given their importance for malaria prevention and control, any further reduction in the effectiveness of insecticide-treated nets could lead to a resurgence of morbidity and mortality.
In response to this threat, dual-acting insecticide-treated bednets, which combine a pyrethroid with another compound, have been developed to restore control of pyrethroid-resistant malaria vectors. The first new type of ITN combines pyrethroids with PIPERONYL BUTOXIDE (PBO), a synergist that enhances the effectiveness of pyrethroids by neutralizing detoxifying enzymes associated with pyrethroid resistance10. In experimental huts and cluster randomized controlled trials (cRCT) ITNs containing pyrethroids and PBO have shown superior entomological benefits compared to ITNs containing only pyrethroids and epidemiological efficacy. They have since received a conditional WHO recommendation for distribution in areas where vectors exhibit resistance to pyrethroids, leading to a significant increase in their distribution in endemic countries in recent years18. However, the pyrethroid-PBO ITN is not without limitations. Notably, there are concerns about their durability after prolonged home use. Pilot studies in West Africa also suggest that pyrethroid-PBO mosquito nets may provide more limited benefit in areas with increased pyrethroid resistance mediated by complex and multiple mechanisms. Thus, for effective and sustainable vector control, it is necessary to use more types of insecticide-treated bed nets, preferably containing other new insecticides to which vectors are sensitive.
Recently, insecticide-treated bed nets have become available that combine pyrethroids with fipronil, an azole insecticide that disrupts mitochondrial function. Chlorfenopyr represents a new method for controlling disease vectors that have developed complex resistance mechanisms to existing insecticides. The pyrethroid-chlorphenopyr ITN (Interceptor G2), developed by BASF, has demonstrated pyrethroid-resistant malaria in pilot trials in Benin, Burkina Faso, Côte and Tanzania. Vector control has improved and is now World Health Organization prequalified. Large-scale trials and pilot distribution programs in some countries have also demonstrated evidence of epidemiological impact. Specifically, RCTs in Benin and Tanzania demonstrated that Interceptor G2 reduced childhood malaria incidence by 46% and 44% over 2 years, respectively, compared with ITN using standard pyrethroids alone. Based on these results, the World Health Organization recently issued a strong recommendation for the use of bed nets treated with the insecticide pyrethroid-chlorphenopyr rather than bed nets containing pyrethroids alone in areas where vectors are resistant to pyrethroids. Insecticide-treated bed nets to prevent malaria. This has led to a significant increase in global demand and orders for pyrethroid-treated mosquito nets installed in endemic countries. The development of more innovative varieties of high-performance pyrethroid and fipronil bed nets by several manufacturers with strong manufacturing capabilities will help improve the insecticide-treated bed net market, increase competition, and lead to easier access to more affordable insecticide-treated bed nets. Bed nets.Insecticidal bed nets for optimal vector control.
Post time: Oct-17-2023