***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Background There is growing concern that malaria vector resistance to pyrethroid insecticides may reduce the effectiveness of long-lasting insecticidal nets ( LLINs ) . Combination LLINs are design ed to control susceptible and pyrethroid-resistant mosquito population s through a mixture of pyrethroid with piperonyl butoxide ( PBO ) synergist . A cluster r and omized trial with entomology outcome measures was conducted in Mali to determine the added benefit over mono-treated pyrethroid predecessors . Four LLIN treatments ; permethrin + PBO , permethrin , deltamethrin + PBO , and deltamethrin , were r and omly allocated to four villages each ( 16 villages total ) and distributed to cover every sleeping place . Entomological monitoring of indoor Anopheles resting densities , host preference , vector longevity , and sporozoite rates were monitored every 2 months over 2 years in 2014 and 2015 . Results Bottle bioassays confirmed permethrin and deltamethrin resistance in Anopheles gambiae sensu lato ( s.l . ) , ( the predominant species throughout the study ) with pre-exposure to PBO indicating partial involvement of oxidases . Between 2014 and 2015 the mean indoor resting density was greater in the deltamethrin + PBO LLIN arm than the deltamethrin LLIN arm at 3.05 ( 95 % CI 3.00–3.10 ) An . gambiae s.l . per room per day compared with 1.9 ( 95 % CI 1.87–1.97 ) . There was no significant difference in sporozoite rate at 3.97 % ( 95 % CI 2.91–5.02 ) for the deltamethrin LLIN arm and 3.04 % ( 95 % CI 2.21–3.87 ) for deltamethrin + PBO LLIN arm ( P = 0.17 ) . However , when analysed by season there was some evidence that the sporozoite rate was lower in the deltamethrin + PBO LLIN arm than deltamethrin LLIN arm during the rainy/high malaria transmission seasons at 1.95 % ( 95 % CI 1.18–2.72 ) and 3.70 % ( 95 % CI 2.56–4.84 ) respectively ( P = 0.01 ) . Conclusions While there was some evidence that An . gambiae s.l . sporozoite rates were lower in villages with deltamethrin + PBO LLINs during the high malaria transmission seasons of 2014–2015 , there was no reduction in parity rates or indoor resting densities . There was also no evidence that permethrin + PBO LLINs provided any improved control when compared with permethrin LLINs . Combination nets may have a greater impact in areas where mixed function oxidases play a more important role in pyrethroid resistance Summary Background Progress in malaria control is under threat by wide-scale insecticide resistance in malaria vectors . Two recent vector control products have been developed : a long-lasting insecticidal net that incorporates a synergist piperonyl butoxide ( PBO ) and a long-lasting indoor residual spraying formulation of the insecticide pirimiphos-methyl . We evaluated the effectiveness of PBO long-lasting insecticidal nets versus st and ard long-lasting insecticidal nets as single interventions and in combination with the indoor residual spraying of pirimiphos-methyl . Methods We did a four-group cluster r and omised controlled trial using a two-by-two factorial design of 48 clusters derived from 40 villages in Muleba ( Kagera , Tanzania ) . We r and omly assigned these clusters using restricted r and omisation to four groups : st and ard long-lasting insecticidal nets , PBO long-lasting insecticidal nets , st and ard long-lasting insecticidal nets plus indoor residual spraying , or PBO long-lasting insecticidal nets plus indoor residual spraying . Both st and ard and PBO nets were distributed in 2015 . Indoor residual spraying was applied only once in 2015 . We masked the inhabitants of each cluster to the type of nets received , as well as field staff who took blood sample s. Neither the investigators nor the participants were masked to indoor residual spraying . The primary outcome was the prevalence of malaria infection in children aged 6 months to 14 years  assessed by cross-sectional surveys at 4 , 9 , 16 , and 21 months after intervention . The endpoint for assessment of indoor residual spraying was 9 months and PBO long-lasting insecticidal nets was 21 months . This trial is registered with Clinical Trials.gov , number NCT02288637 . Findings 7184 ( 68·0 % ) of 10 560 households were selected for post-intervention survey , and 15 469 ( 89·0 % ) of 17 377 eligible children from the four surveys were included in the intention-to-treat analysis . Of the 878 households visited in the two indoor residual spraying groups , 827 ( 94 % ) had been sprayed . Reported use of long-lasting insecticidal nets , across all groups , was 15 341 ( 77·3 % ) of 19 852 residents after 1 year , decreasing to 12 503 ( 59·2 % ) of 21 105 in the second year . Malaria infection prevalence after 9 months was lower in the two groups that received PBO long-lasting insecticidal nets than in the two groups that received st and ard long-lasting insecticidal nets ( 531 [ 29 % ] of 1852 children vs 767 [ 42 % ] of 1809 ; odds ratio [ OR ] 0·37 , 95 % CI 0·21–0·65 ; p=0·0011 ) . At the same timepoint , malaria prevalence in the two groups that received indoor residual spraying was lower than in groups that did not receive indoor residual spraying ( 508 [ 28 % ] of 1846 children vs 790 [ 44 % ] of 1815 ; OR 0·33 , 95 % CI 0·19–0·55 ; p<0·0001 ) and there was evidence of an interaction between PBO long-lasting insecticidal nets and indoor residual spraying ( OR 2·43 , 95 % CI 1·19–4·97 ; p=0·0158 ) , indicating redundancy when combined . The PBO long-lasting insecticidal net effect was sustained after 21 months with a lower malaria prevalence than the st and ard long-lasting insecticidal net ( 865 [ 45 % ] of 1930 children vs 1255 [ 62 % ] of 2034 ; OR 0·40 , 0·20–0·81 ; p=0·0122 ) . Interpretation The PBO long-lasting insecticidal net and non-pyrethroid indoor residual spraying interventions showed improved control of malaria transmission compared with st and ard long-lasting insecticidal nets where pyrethroid resistance is prevalent and either intervention could be deployed to good effect . As a result , WHO has since recommended to increase coverage of PBO long-lasting insecticidal nets . Combining indoor residual spraying with pirimiphos-methyl and PBO long-lasting insecticidal nets provided no additional benefit compared with PBO long-lasting insecticidal nets alone or st and ard long-lasting insecticidal nets plus indoor residual spraying . Funding UK Department for International Development , Medical Research Council , and Wellcome Trust Summary Background Scale-up of insecticide-based interventions has averted more than 500 million malaria cases since 2000 . Increasing insecticide resistance could herald a rebound in disease and mortality . We aim ed to investigate whether insecticide resistance was associated with loss of effectiveness of long-lasting insecticidal nets and increased malaria disease burden . Methods This WHO-coordinated , prospect i ve , observational cohort study was done at 279 clusters ( villages or groups of villages in which phenotypic resistance was measurable ) in Benin , Cameroon , India , Kenya , and Sudan .  Pyrethroid long-lasting insecticidal nets were the principal form of malaria vector control in all study areas ; in Sudan this approach was supplemented by indoor residual spraying .  Cohorts of children from r and omly selected households in each cluster were recruited and followed up by community health workers to measure incidence of clinical malaria and prevalence of infection . Mosquitoes were assessed for susceptibility to pyrethroids using the st and ard WHO bioassay test . Country-specific results were combined using meta- analysis . Findings Between June 2 , 2012 , and Nov 4 , 2016 , 40 000 children were enrolled and assessed for clinical incidence during 1·4 million follow-up visits . 80 000 mosquitoes were assessed for insecticide resistance . Long-lasting insecticidal net users had lower infection prevalence ( adjusted odds ratio [ OR ] 0·63 , 95 % CI 0·51–0·78 ) and disease incidence ( adjusted rate ratio [ RR ] 0·62 , 0·41–0·94 ) than did non-users across a range of resistance levels . We found no evidence of an association between insecticide resistance and infection prevalence ( adjusted OR 0·86 , 0·70–1·06 ) or incidence ( adjusted RR 0·89 , 0·72–1·10 ) . Users of nets , although significantly better protected than non-users , were nevertheless subject to high malaria infection risk ( ranging from an average incidence in net users of 0·023 , [ 95 % CI 0·016–0·033 ] per person-year in India , to 0·80 [ 0·65–0·97 ] per person year in Kenya ; and an average infection prevalence in net users of 0·8 % [ 0·5–1·3 ] in India to an average infection prevalence of 50·8 % [ 43·4–58·2 ] in Benin ) . Interpretation Irrespective of resistance , population s in malaria endemic areas should continue to use long-lasting insecticidal nets to reduce their risk of infection . As nets provide only partial protection , the development of additional vector control tools should be prioritised to reduce the unacceptably high malaria burden . Funding Bill & Melinda Gates Foundation , UK Medical Research Council , and UK Department for International Development Spatial analyses of the effect of insecticide (permethrin)-treated bed nets ( ITNs ) on nearby households both with and without ITNs was performed in the context of a large-scale , group-r and omized , controlled mortality trial in Asembo , western Kenya . Results illustrate a protective effect of ITNs on compounds lacking ITNs located within 300 meters of compounds with ITNs for child mortality , moderate anemia , high-density parasitemia , and hemoglobin levels . This community effect on nearby compounds without nets is approximately as strong as the effect observed within villages with ITNs . This implies that in areas with intense malaria transmission with high ITN coverage , the primary effect of insecticide-treated nets is via area-wide effects on the mosquito population and not , as commonly supposed , by simple imposition of a physical barrier protecting individuals from biting . The strength of the community effect depended upon the proportion of nearby compounds with treated nets . To maximize their public health impact , high coverage with treated nets is essential Background Long-lasting insecticide-treated nets ( LLINs ) are one of the main methods used for controlling malaria transmission in Mozambique . The proliferation of several types of LLINs and the re-emergence of insecticide resistance in the local vector population s poses challenges to the local malaria control programme on selecting suitable insecticide-based vector control products . Therefore , this study evaluated the insecticide susceptibility and bio-efficacy of selected new LLINs against wild population s of Anopheles funestus sensu lato and A. gambiae s.l . from Northern and Central Mozambique . The study also investigated whether the insecticide contents on the LINNs fabrics were within the WHOPES recommended target range . Methods The susceptibility of 2–5 day old wild female A. funestus and A. gambiae sensu stricto against the major classes of insecticides used for vector control , viz : deltamethrin ( 0.05 % ) , permethrin ( 0.75 % ) , propoxur ( 0.1 % ) , bendiocarb ( 0.1 % ) and DDT ( 4 % ) , was determined using WHO cylinder susceptibility tests . WHO cone bioassays were conducted to determine the bio-efficacy of both pyrethroid – only LLINs ( Olyset ® , Permanet 2.0 ® , NetProtect ® and Interceptor ® ) and , Permanet 3.0 ® a combination LLIN against A. funestus s.s , from Balama , Mocuba and Milange districts , respectively . The bio-efficacy of LLINs against the insectary-susceptible A. arabiensis ( Durban strain ) was assessed , as well . Untreated bed net swatches were used as negative controls . Chemical analyses , by high performance liquid chromatography , were undertaken to assess whether the insecticide contents on the LLINs fabrics fell within recommended target dose 
    Output:
    
Authors ' conclusions In areas of high insecticide resistance , pyrethroid‐PBO nets increase mosquito mortality and reduce blood feeding rates , and results from a single clinical trial demonstrate that this leads to lower malaria prevalence .
There is little evidence to support higher entomological efficacy of pyrethroid‐PBO nets in areas where the mosquitoes show lower levels of resistance to pyrethroids .