Evaluating the impact of South–North Joint Malaria Control Project on spatiotemporal transmission dynamics in South Korea using dynamic mode decomposition

BACKGROUND: Malaria re-emerged on the Korean Peninsula after elimination in 1979, driven by cross-border mosquito incursions and imported infections. Despite ongoing control efforts, transmission persists near the demilitarized zone (DMZ). Major national programs, including the South-North Joint Malaria Control Project (2008-2011) and the Korean 5-Year Malaria Re-Elimination Plan (2019-2023), aimed to interrupt transmission and achieve elimination. METHODS: We applied the compatible-window dynamic mode decomposition (CwDMD) framework to malaria incidence data from 2001 to 2024 across 17 provinces and 37 subregions. This data-driven approach identified dominant spatiotemporal transmission modes and assessed structural changes in regional synchrony and hotspot connectivity before and after interventions. RESULT: The South-North Joint Control Project (2008-2011) achieved a 63% reduction in national incidence between 2007 and 2011 and disrupted synchronization among border and metropolitan regions, indicating a shift in transmission structure. In contrast, the 5-Year Re-Elimination Plan (2019-2023) was associated with an approximately 49% decrease in incidence from 2018 to its lowest level in 2021; however, incidence subsequently increased by about 30% by 2023 relative to the pre-implementation level in 2018, accompanied by partial re-emergence of regional synchrony. CONCLUSION: Sustained malaria control requires not only reducing incidence but also weakening temporal and spatial coupling among high-risk regions. The CwDMD framework offers a robust tool for evaluating the impact of control measures and guiding adaptive, region-specific strategies toward malaria elimination in South Korea.