title: The AvecNet Trial to assess whether addition of pyriproxyfen, an insect juvenile hormone mimic, to long-lasting insecticidal mosquito nets provides additional protection against clinical malaria over current best practice in an area with pyrethroid-resistant vectors in rural Burkina Faso: study protocol for a randomised controlled trial.
abstract: BACKGROUND
  Recent reductions in malaria in sub-Saharan Africa have been associated with increased coverage with long-lasting insecticidal nets (LLINs). Pyrethroids are currently the only insecticide class used for treating nets, and the rapid increase in resistance to pyrethroids in vector mosquitoes may jeopardise future vector control. Nets containing a novel combination of permethrin, a pyrethroid, and pyriproxyfen, an insect juvenile hormone mimic, (PPF-LLIN) may enhance malaria control, as well as reducing the spread of pyrethroid-resistant mosquitoes. This trial will determine whether PPF-LLINs provide incremental protection against malaria over current best practice of LLINs and prompt treatment in an area with pyrethroid-resistant vectors.
  
  
  METHODS
  A 2 armed cluster-randomised controlled trial will be conducted in Burkina Faso to assess whether PPF-LLIN (containing 2% permethrin and 1% pyriproxyfen w/w) provide better protection against clinical malaria in children than 2% permethrin-treated LLINs. Study subjects will be recruited and provided with LLINs at the start of the study. The LLINs will be exchanged for PPF-LLIN by cluster in a step-wedge fashion so 3 months before the end of the 2 year trial all participants will have a PPF-LLIN. The primary endpoint will be clinical malaria incidence measured by passive case detection in a cohort of children, aged 6 months to 5 years. Anaemia and parasite prevalence will also be measured in children during cross-sectional surveys. Exposure to malaria parasites will be assessed using light traps followed by identification of common vector species and their sporozoite infection rates. Safety evaluation will include recording of adverse events and pregnancy outcomes. The main endpoint analysis will include adjusting for distance between village clusters with different types of nets, as the impact of PPF-LLIN is likely to increase as larger areas are dominated by PPF-LLIN, reducing the spill over of mosquitoes from villages with LLINs.
  
  
  CONCLUSIONS
  The step-wedge design is to measure the impact of an incrementally delivered environmental intervention where we expect the degree of control to be improved as more people use PPF-LLIN over a larger area. Trial findings will help inform policy makers on the effectiveness of PPF-LLIN nets for malaria control in areas of pyrethroid resistance.
  
  
  BACKGROUND
  ISRCTN21853394 - AvecNet, registered on 3 April 2013.
authors: Centre National de Recherche et de Formation sur le Paludisme (CNRFP), Ouagadougou, Burkina Faso. t.alfred@fasonet.bf.
authors: Alfred B
authors: AB
authors: Tiono
authors: School of Biological Sciences and Biomedicine, Durham University, Durham, UK. mpinder@mrc.gm.|Medical Research Council Unit The Gambia, P.O. Box 273, Banjul, The Gambia. mpinder@mrc.gm.
authors: Margaret
authors: M
authors: Pinder
authors: Centre National de Recherche et de Formation sur le Paludisme (CNRFP), Ouagadougou, Burkina Faso. n.fale.cnlp@fasonet.bf.
authors: Sagnon
authors: S
authors: N'Fale
authors: Liverpool School of Tropical Medicine, Liverpool, UK. Faragher@liv.ac.uk.
authors: Brian
authors: B
authors: Faragher
authors: Swiss Tropical and Public Health Institute, Basle, Switzerland. Thomas-A.Smith@unibas.ch.
authors: Tom
authors: T
authors: Smith
authors: Swiss Tropical and Public Health Institute, Basle, Switzerland. Mariabeth.silkey@unibas.ch.
authors: Mariabeth
authors: M
authors: Silkey
authors: Liverpool School of Tropical Medicine, Liverpool, UK. hranson@liverpool.ac.uk.
authors: Hilary
authors: H
authors: Ranson
authors: School of Biological Sciences and Biomedicine, Durham University, Durham, UK. S.W.Lindsay@durham.ac.uk.
authors: Steve W
authors: SW
authors: Lindsay
mesh_terms: D000367:Age Factors; D000818:Animals; D000852:Anopheles / Q000187:drug effects* / Q000469:parasitology; D002050:Burkina Faso / Q000453:epidemiology; D002675:Child, Preschool; D004199:Disease Vectors; D006801:Humans; D015994:Incidence; D007223:Infant; D007305:Insecticide Resistance; D057148:Insecticide-Treated Bednets; D007306:Insecticides; D008288:Malaria / Q000175:diagnosis / Q000453:epidemiology / Q000517:prevention & control* / Q000635:transmission; D009032:Mosquito Control / Q000379:methods*; D010961:Plasmodium / Q000254:growth & development*; D011725:Pyridines; D012107:Research Design; D013997:Time Factors
chemical_list: D007306:Insecticides; D011725:Pyridines; C055613:pyriproxyfen