Intervention
malaria
MALARIA
Selected clusters (Fig. Map of the study area in Bomi County, Liberia. Control clusters are shown in grey, Active clusters are shown in red, pairing is shown with black lines. The division between upland and coastal regions is shown with dashed orange line. Administrative boundaries were used to select villages; no clusters were selected in the central administrative district. Inset: map of region, main map area shown as an orange rectangleEpidemiological effect of DWL in 20 paired clusters Bomi County, Liberia. Paired clusters with their corresponding village names and cluster numbers are shown along with whether they were randomized to receive DWL or notDWL was manufactured as a custom prototype by Vestergaard Frandsen SA. This prototype was a non-woven polypropylene impregnated with fenpyroximate and abamectin which are chemicals previously used in horticulture, but have not been applied to mosquito control. The non-woven material had no additional surface treatments. Fenpyroximate is a NADH-coenzyme Q reductase inhibitor (IRAC 21a), while abamectin acts on the glutamate-gated chloride channel (IRAC 6). Chemicals with these modes of action have not been widely used to control malaria mosquitoes.Installation of the DWL was conducted by groups of 10 to 12 installers who were selected by village leadership and who were provided with non-cash incentives during the installation period (Additional file Typical housing design in Bomi County, Liberia showing open gables and ceilings. Exterior photo shows the large gable allowing for cross-breeze and mosquito entry. Interior photo shows interior dividing walls extending approximately 2 m above the floor, an LLIN hung above the bed, and recycled LLINs sewn together to make a ceilingPhotos of typical installation of DWL in houses in Bomi County, Liberia. Deltamethrin LLINs were present as an additional control measure in both arms of the study. Ceilings and windows were covered with DWL using wooden stripsCommunity consultations with village leadership were conducted before study activities commenced and continued throughout the study period. Verbal and written consent was obtained before participation in the survey, including entry of houses for DWL installation and epidemiological surveys. Consent forms were written in simple English, which is the trade language in the area, and village leadership were involved in coordination and translation of the consent process. Treatment or testing for malaria was not conditional on participating in the trial.