A compartmental metapopulation mathematical model simulating malaria transmission across Namibia, Angola, and Zambia finds that Namibia could achieve pre-elimination status by 2034 — but only under a coordinated regional strategy. Managing cross-border travel targeting 50% of migrants and travelers, combined with scaled vector control across all three nations, could reduce Namibia's case burden by up to 33% over a decade. Critically, isolated national strategies proved insufficient to counter importation pressure from neighboring high-transmission Angola and Zambia. Simulated insecticide resistance produced only marginal incidence increases in Angola and Zambia, suggesting some health system resilience.
This modeling work adds quantitative weight to a long-recognized but politically difficult principle in infectious disease control: low-transmission countries embedded within high-transmission regions cannot eliminate a pathogen through domestic effort alone. The finding echoes lessons from malaria programs in southern Africa, where imported cases routinely undermine hard-won local gains. For global health practitioners, the 33% reduction figure from cross-border management alone — without additional interventions — is a striking policy lever. Practically, however, achieving 50% migrant screening coverage across porous borders in resource-limited settings is a substantial assumption. The model's reliance on climatic variability and current intervention coverage estimates introduces further uncertainty. As a preprint posted to medRxiv and not yet peer-reviewed, these projections should be treated as illustrative rather than definitive. Still, the framework is a meaningful, policy-relevant contribution to regional elimination strategy — confirmatory in principle, but usefully precise in its quantitative outputs.