Insecticide-treated bednet coverage in Africa 2006-2024: a spatiotemporal analysis of net ownership, use, age and type

Abstract Since their rapid adoption from the mid 2000s, insecticide-treated nets (ITNs) have been one of the most ubiquitous and impactful malaria interventions in Africa. Facing insecticide resistance and ever-increasing resource constraints, there is a growing need to revise previous modelling efforts of ITN coverage to better reflect the current epidemiological reality. Comprehensive estimates of ITN coverage must account for factors such as net type, net age, and user behaviours. By leveraging improved data availability, we propose a mathematically rigorous and interpretable ITN coverage model that extends previous national-level ITN models to the subnational level across 44 countries in Africa. The presented Multitype-ITN (MITN) model is used to construct longitudinal estimates of net demography by age and type from 2006 to 2024, and provide insights on potential sources of ITN distribution inefficiencies. Our findings show a significant increase in the uptake of next-generation ITNs, and thus reflect an increasingly diverse market. However, longitudinal coverage suggests stagnation in key metrics of net ownership such as nets-per-capita, access and use, alongside a downwards trend in utilisation – number of users per net. Coupled with observed stationary levels of use rate – proportion of people with access that also use nets. There are also early signs of interventions failing to meet the demands of increasing populations. Our results provide more nuanced metrics of ITN coverage that account for factors such as type and age, which may inform the design of future net allocation policies. Competing Interest Statement The authors have declared no competing interest. Funding Statement This work was supported, in whole or in part, by the Gates Foundation [INV-055192]. The conclusions and opinions expressed in this work are those of the author(s) alone and shall not be attributed to the Foundation. Under the grant conditions of the Foundation, a Creative Commons Attribution 4.0 License has already been assigned to the Author Accepted Manuscript version that might arise from this submission. This work also includes funding support from the Australian Government, National Health and Medical Research Council (Award No: GNT2025280). Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: The household-level survey data used in this analysis is publicly available from the DHS (https://dhsprogram.com/) and MICS (https://mics.unicef.org/) websites. The national-level-aggregated survey data were gleaned from reports available at the MIS website (https://www.malariasurveys.org/). Data on manufacturer delivery of nets are available from the AMP Net Mapping Project (https://allianceformalariaprevention.com/working-groups/net-mapping/). Data on NMCP distribution of nets were provided by WHO. I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes