A survey-informed mathematical model of preparedness-constrained cholera transmission in Sudan

Cholera outbreaks in humanitarian settings are driven by a complex interplay between environmental contamination, behavioural responses, and severe disruptions to public-health infrastructure. Although numerous mathematical models have incorporated awareness, vaccination, and environmental transmission, they generally assume that awareness translates directly into protective behaviour, overlooking the practical constraints imposed by displacement, poverty, misinformation, and limited access to water, sanitation, and healthcare. Motivated by the 2024–2025 Sudan cholera epidemic, we develop a survey-informed ordinary differential equation model that explicitly distinguishes between cholera knowledge and effective preparedness, thereby linking household-level behavioural information to population-level epidemic dynamics. Preparedness is modelled as a dynamic state that is promoted by disease knowledge while being diminished by structural vulnerability and misinformation. Model parameterization is performed in two stages: preparedness-related quantities are estimated from a community survey conducted among internally displaced populations, whereas the epidemic layer is semi-calibrated to the reconstructed national weekly cholera incidence curve. To evaluate the robustness of the calibration, deterministic digitization sensitivity, pixel-level Monte Carlo uncertainty analyses, and a practical identifiability assessment of the baseline treatment-entry parameter were performed. The calibrated model successfully reproduces the observed multi-wave epidemic pattern and demonstrates that repeated transient environmental amplification is necessary to explain the outbreak dynamics. The results further show that high cholera knowledge alone is insufficient to substantially reduce transmission when structural vulnerability remains high, whereas improvements in preparedness, treatment access, and environmental clearance markedly reduce both peak incidence and cumulative disease burden. These findings identify preparedness as a missing mechanistic link between awareness and epidemic control and provide a robust survey-informed modelling framework for investigating cholera transmission and intervention strategies in conflict-affected and displaced populations.