Study design, sample size and randomisation
malaria
MALARIA, ADVERSE EVENTS
The study was designed as a non-inferiority trial to determine if VECTRON™ T500 was no worse than Fludora® Fusion in terms of its impact on the densities of the main malaria mosquito vector in the study area. Power analysis showed that, using 8 clusters per arm and at least 49-man night collections per cluster, the trial had 80% power to show that VECTRON™ T500 would not lead to higher mean numbers of mosquitoes per man night assumed in the Fludora® Fusion arm by a non-inferiority margin of 50%. The baseline census data was used to divide the study area into 24 clusters, each consisting of one village or a group of village hamlets with approximately 150–500 households. The individual clusters were the unit of randomisation. Eight of these clusters were eliminated due to inaccessibility, poor acceptance of the study and low vector density as revealed by the baseline entomological surveys. The remaining 16 study clusters were pair matched based on baseline Spatial distribution of IRS study clusters in VECTRON™ T500 (pink) and Fludora® Fusion (light blue) arms in the Za-Kpota sub-District of Benin. Clusters in white were treated but are not included in the post-IRS evaluation studies.Following IRS application, studies were conducted to assess the perceived adverse events and acceptability of each IRS product by homeowners and the entomological impact of each intervention on the vector populations was assessed with regards to vector species composition, vector density, resting behaviour, insecticide susceptibility, human biting rate, sporozoite rate and entomological inoculation rate. WHO cone bioassays were also performed at monthly intervals to investigate the residual efficacy of each IRS formulation.