Understanding how mobility and spatial disparities shape COVID-19 transmission under rotational and localized lockdowns

Abstract

Non-pharmaceutical interventions (NPIs) such as city-level curfews and local lockdowns were implemented to control SARS-CoV-2 transmission, yet their effectiveness at fine spatial scales remains uncertain. We evaluated a rotational lockdown policy in Bogotá, Colombia, applied at the locality level—an administrative aggregation of neighborhoods. Mobility patterns derived from mobile phone data were analyzed to quantify commuting changes, defined as relative variations in movement compared to a pre-intervention baseline (one month before restrictions). We distinguished between external mobility (between localities) and internal mobility (within localities). Using epidemiological surveillance data, we estimated the effective reproductive number ($\:{R}_{eff}$) and assessed its association with mobility reductions. A compartmental transmission model simulated counterfactual epidemic trajectories without NPIs, comparing predicted and observed infections, mortality, and $\:{R}_{eff}$. The intervention reduced inter-locality mobility by up to 40% but only minimally affected within-locality movement (median change < 5%), a descriptive result based on mobility data. Early lockdown cycles produced the largest declines in transmission (up to 27% reduction in cases), while subsequent rounds showed diminishing effects. Socioeconomic heterogeneity explained substantial spatial variability in transmission dynamics, revealing stronger associations between mobility and $\:{R}_{eff}$ in localities with lower socioeconomic status. Our findings demonstrate that fine-scale NPIs can transiently reduce community transmission, but their impact depends on the spatial distribution of mobility and socioeconomic inequalities across the urban landscape.