To explore housing modification as a malaria control intervention, and to assess the degree to which it may offer protection in moderate to high malaria endemicity settings, we propose a two-phase study evaluating epidemiological and entomological effectiveness, cost-effectiveness, feasibility, and acceptability of housing modification in Uganda. The first phase will be a pilot implementation assessing the feasibility of candidate housing modification interventions, followed by a cluster randomised control trial of the most effective, scalable, and cost-effective interventions.
The study will be conducted in two phases, beginning with a pilot (Phase I). The aim of the pilot will be 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 housing modifications will include: (1) full house screening (eaves and windows), (2) partial house screening (eaves or ceiling), (3) eave tubes, and (4) eave ribbons. Community input will be sought during the development of the housing prototypes. In the pilot, all 4 interventions will be implemented in both modern and traditional houses, plus a control arm in each group. All households will have access to PBO LLINs. Community input will be sought during the development of the housing prototypes. The pilot will include 10 arms in total, each consisting of 20 households, equal to 200 households (160 in the intervention and 40 in the control arm) in total. The feasibility and effectiveness of the interventions will be assessed through a qualitative study (FGDs and interviews), evaluation of the costs and implementation of the interventions, and entomology surveys (using CDC light traps). One to two housing interventions will be selected for Phase II following the review and discussion of the pilot results with the trial steering committee. Phase II will include a cluster-randomised trial. A cluster will be defined as a village (or segment of a village consisting of \~100 households). In the cluster-randomised trial, up to 2 interventions vs 1 control arm will be assessed in 20 clusters per arm (60 clusters total). The clusters will be non-contiguous, with a buffer zone of 300-500m. All households in the selected clusters will have PBO LLINs; households in intervention clusters will also receive the specified housing modifications. 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.
Study Type
The eave tubes are PVC tubes with a diameter of 15 cm installed in the outer wall of occupied rooms (e.g. bedrooms and living rooms but not storage rooms) at 1.5-2 m intervals, fitted with electrostatic mesh inserts coated with insecticides. No additional screening will be done. All households will be provided with piperonyl butoxide (PBO) long-lasting insecticidal nets (LLINs) - one for every two residents.
Eave ribbons are 15 cm-wide triple-layered hessian fabrics (burlap-line fabric woven from sisal fibres, procured locally), in lengths starting 1 m that can be attached to houses using nails, adhesives or Velcro, without completely closing eave-spaces. The eave ribbons will be treated by study staff with a commonly used spatial repellent, transfluthrin. Eave ribbons will be retreated by study staff after 6 months (only in Phase II, if selected for inclusion in the cluster-randomised trial). All households will be provided with piperonyl butoxide (PBO) long-lasting insecticidal nets (LLINs) - one for every two residents.
Infectious Diseases Research Collaboration
Kampala, Central Region, Uganda
Incidence of malaria
Number of incident episodes of clinical malaria per time of observation. Incident episodes of malaria defined as any treatment for malaria \> 14 days after any prior treatment for malaria
Time frame: 12 months following housing modification
Parasite prevalence
Proportion of study participants with a thick blood smear positive for asexual parasites as measured by microscopy
Time frame: 12 months following housing modification
Prevalence of anaemia
Proportion of haemoglobin measurements categorised as anaemia as per WHO age-stratified guidelines
Time frame: 12 months following housing modification
Vector density
Number of female Anopheles mosquitoes captured/room per night by CDC light traps
Time frame: 12 months following housing modification
Sporozoite rate
Proportion of captured female Anopheles mosquitoes that test positive for sporozoites
Time frame: 12 months following housing modification
Annual entomological inoculation rate
Number of infected bites per person per year (human biting rate x sporozoite rate x 365 days/year)
Time frame: 12 months following housing modification
Proportion of mosquitoes with insecticide resistance
Proportion of mosquitoes with phenotypic expression of insecticide resistance or containing genetic polymorphisms associated with resistance to insecticides of interest as identified by PCR
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
PREVENTION
Masking
NONE
Enrollment
2,422
Full house screening includes screening eaves/ceilings, ventilation openings, and windows. Eaves/ceiling, air vents, and windows of eligible houses will be screened with wire mesh or other locally available screening materials. or ceilings, if eaves are closed" and ventilation openings. We are also filling in any gaps in the walls. All households will be provided with piperonyl butoxide (PBO) long-lasting insecticidal nets (LLINs) - one for every two residents.
Partial screening will include either screening of the eaves or installing a screened ceiling, where no ceiling is present. In traditional houses, a netting (either insecticide-impregnated or untreated) may be either fixed in multiple places in the rafters or by hanging from a single central point and attached to the walls. No other screening or filling of the gaps will be done in partially screened houses.All households will be provided with piperonyl butoxide (PBO) long-lasting insecticidal nets (LLINs) - one for every two residents.
Time frame: 12 months following housing modification
Proportion of individuals satisfied with the interventions
Indicator of acceptability
Time frame: 12 months following housing modification
Proportion of households that require minimal maintenance of the implemented intervention over the period of the study, by study intervention
Indicator of durability
Time frame: 12 months following housing modification
Longer term cost of the maintenance and upkeep of the implemented intervention, by study intervention
Indicator of durability
Time frame: 12 months following housing modification
Costs of housing improvements, including maintenance, by improvement type
Indicator of feasibility
Time frame: 12 months following housing modification
Incremental cost-effectiveness ratios (ICER) of each package
Cost per malaria case averted, Cost per DALY averted
Time frame: 12 months following housing modification
Proportion of households that received the assigned housing modification
Indicator of fidelity
Time frame: 12 months following housing modification
Proportion of households that received 1 PBO LLIN for every 2 residents
Indicator of fidelity
Time frame: 12 months following housing modification
Proportion of households that received full/partial/no housing modifications
Dose delivered
Time frame: 12 months following housing modification
Proportion of households that received adequate/inadequate/no PBO LLINs
Dose delivered
Time frame: 12 months following housing modification
Proportion of households that utilized full/partial/no housing modifications
Dose received
Time frame: 12 months following housing modification
Proportion of household residents that slept under a PBO LLIN the previous night
Dose received
Time frame: 12 months following housing modification
Proportion of households that were fully covered by the assigned housing modification
Indicator of reach
Time frame: 12 months following housing modification
Proportion of household residents that were fully covered by the PBO LLINs
Indicator of reach Proportion of households fully covered by both the modifications \& PBO LLINs
Time frame: 12 months following housing modification
Proportion of households fully covered by both the modifications & PBO LLINs
Indicator of reach
Time frame: 12 months following housing modification