An observational study evaluating the epidemiological and entomological impacts of piperonyl butoxide insecticide-treated nets (ITNs) compared to a combination of indoor residual spraying (IRS) plus standard pyrethroid-only ITNs in Amhara Region, Ethiopia, 2019–2023
Introduction National malaria programmes must weigh the relative benefits of different vector control and elimination tools to prioritise resource allocation with the greatest impact. This study assesses the epidemiological and entomological impacts of piperonyl butoxide insecticide-treated nets (PBO ITN-only arm) compared with the combination of two annual non-pyrethroid indoor residual spraying (IRS) campaigns and standard pyrethroid ITNs (IRS+Standard Pyrethroid ITN arm) in the Amhara region of Ethiopia.Methods An open-label, stratified block-cluster randomised trial was designed to compare the impacts of the two intervention arms. ITN distribution took place from June to July 2021. IRS campaigns took place from June to July 2021 and again in June 2022. Confirmed malaria cases reported during the high transmission season (September to December) were compared in the 2 years before (2019 and 2020) vs the 2 years after (2021 and 2022) the 2021 campaigns. The difference in An. gambiae s