Influence of spatial connectivity on the spread of Mpox in Maï-Ndombe province, Democratic Republic of the Congo, 2025

Background The spread of Mpox in the DRC is strongly influenced by human mobility in a context of environmental constraints and inequalities in accessibility. The province of Maï-Ndombe, with its fragmented transport network and dependence on waterways, is a relevant setting for analyzing the impact of spatial connectivity on epidemic dynamics. Objective Quantify spatial connectivity in the area and assess its influence on the spread of Mpox in Maï-Ndombe province Methods A spatial connectivity analysis based on a gravity model integrating demographic attractiveness and distance-cost (slope, land use) was combined with a spatialized SEIR model. Inter-zone flows, centrality, and accessibility were quantified. The performance of SEIR models with and without connectivity was compared using RMSE, MAE, and precision gain per zone. Results Flows are concentrated around pivotal areas (Bokoro, Nioki, Mushie), while peripheral areas remain isolated, with accessibility mainly provided by river corridors. The integration of connectivity degrades the overall fit of the model, but improves forecasts in highly connected areas and deteriorates them in poorly connected areas, reflecting marked spatial heterogeneity. Conclusion Connectivity does not strengthen the overall prediction of incidence, but structures the spatial redistribution of risk. These results highlight the importance of targeting interventions in areas with high connectivity, while considering the limitations of local surveillance systems.