Insecticide-treated net use and elimination of malaria in Sub-Saharan African countries: assessing the Global Technical Strategy using an evolutionary game approach.

backgroundMalaria continues to be a major public health challenge in Sub-Saharan Africa (SSA), where the majority of the countries have not met the World Health Assembly's endorsed Global Technical Strategy (GTS) milestones in 2020 for malaria reduction. Insecticide-treated net (ITN) usage is a well-established and effective intervention, often outperforming other measures such as indoor residual spraying (IRS). However, multiple survey studies have reported improper use of ITNs across various SSA countries. This misuse likely poses an important barrier to the intervention's success, although it remains a largely untested hypothesis.

methodsWe developed a behaviour-incidence model and statistical analysis of historical malaria case reports and ITN usage data to inform ITN utilization and assess progress toward GTS targets. The analysis was conducted in three phases: 1. pre-estimation; 2. estimation; and 3. projection. By fitting the behaviour-incidence model to malaria case and ITN usage data, we derived country-specific constraints that help explain the varying progress of SSA countries toward GTS objectives. Additionally, we employed clustering analyses and optimisation methods to classify countries and obtain country-specific recommendations to increase ITN usage and reduce malaria cases to achieve 2025 and 2030 GTS milestones.

resultsOur results indicate that countries can be classified into different categories based on the transmission rates, mosquito prevalence, and socioeconomic conditions. We demonstrate that while some countries can meet the GTS 2025 and 2030 targets through their ongoing efforts in ITN usage to control malaria, others require enhanced social awareness campaigns, economic assistance, and improvements in ITN efficacy to achieve success. Our analysis emphasizes that country-specific behavioural interventions are essential for accelerating malaria elimination.

conclusionWhile factors such as demographics, political instability, and climate change influence a country's malaria burden, and interventions like IRS are widely used for control, our research highlights the critical role of human behavioural practices in the proper use of ITNs and provides actionable policy insights to enhance their effectiveness. We emphasize the need for tailored strategies to optimize effective ITN use. Actions include improved ITN availability, effectiveness, and use that when combined with alternative vector control tools, vector behaviours, and shelter types, the effort will contribute greatly to countries achieving GTS malaria elimination targets. CLINICAL TRIAL: Not applicable.