Theory, context, and methods
malaria, brick or stone, infections
MALARIA, INFECTIONS
Globally, Uganda is the third highest contributor to malaria cases and accounts for 5% of all infections across the world [The pilot study that we followed was conducted in the predominantly rural part of the district. This study area was selected basing because of the high burden of malaria and ongoing challenges with pyrethroid resistance, the willingness of the local leadership to support the study and availability of infrastructure to enable the team to evaluate the intervention through the health facilities.Subsistence farming and cash cropping dominates the economy. Across the district, sugarcane has been the major cash crop since colonial times, becoming a primary source of household income through a private ‘out grower’ scheme to supply sugarcane to local factories [The study was to be conducted in two phases: a pilot (Phase I) and a full cluster randomized intervention trial (Phase II). The aim of the pilot was to develop and test four types of housing modifications in both modern houses (those with brick or stone walls) and traditionally constructed houses (those with mud walls). The two housing interventions which were most successful in the pilot study (feasible, acceptable, and effective) would then be selected for the full intervention trial. The housing modifications that were piloted included: (1) full house screening (eaves/ceilings, ventilation bricks/openings, and windows), (2) partial house screening (eaves or ceiling), (3) eave tubes, and (4) eave ribbons. All households had access to piperonyl butoxide (PBO) long-lasting insecticidal nets (LLINs) and all housing modifications were provided free of charge to all recipients. Three villages located in Butagaya sub-county, Jinja, were identified as they had a good mix of modern and traditional houses, fewer rented homes, and a willingness of local leaders to support the study (Fig. 
Map of Jinja district showing Butagaya subcounty pilot study site and the pilot villages highlightedA total of 200 houses were enrolled in the pilot study. The houses were mapped using a handheld GPS device, and consent was sought from household members. The inclusion criteria were: (1) at least one adult aged 18 years or older present; (2) agreement of the adult resident to provide informed consent for the pilot study. Individual households were stratified into two categories (modern vs. traditional construction) with 100 households of each category type. The study used block randomization to assign 20 households from each category assigned to the 5 study arms (4 arms received 1 intervention listed in Table 
Types of modifications introduced during the projectPhase II will include a cluster-randomized trial comparing 2 interventions against a control arm across 60 clusters of 100 households. All households will receive PBO LLINs. The impact of the interventions will be assessed through a cohort study, cross-sectional community surveys, entomology surveillance, a qualitative study, and an economic evaluation. The primary outcome of the trial will be clinical malaria incidence in children aged < 60 months as measured in the cohort study. All housing modifications will be provided free of charge to all recipients.