Geospatial tuberculosis hotspots are hubs of TB transmission both within
and across community groups. We aimed to quantify the extent to which
these hotspots account for the spatial spread of TB in a high-burden
setting. We developed spatially coupled models to quantify the spread of
TB from geographic hotspots to distant regions in rural Ethiopia. The
population was divided into three ‘patches’ based on their proximity to
transmission hotspots, namely hotspots, adjacent regions and remote
regions. The models were fitted to five-year notification data aggregated
by the metapopulation structure. Model fitting was achieved with a
Metropolis-Hastings algorithm using a Poisson likelihood to compare
model-estimated notification rate with observed notification rates. A
cross-coupled metapopulation model with assortative mixing by region
closely fit to notification data as assessed by the Deviance Information
Criterion. We estimated 45 hotspot-to-adjacent regions transmission events
and 2 hotspot-to-remote regions transmission events occurred for every
1000 hotspot-to-hotspot transmission events. Although the degree of
spatial coupling is weak, the proportion of infections in the adjacent
region that resulted from mixing with hotspots was high due to the high
prevalence of TB cases in a hotspot region, with approximately 75% of
infections attributable to hotspot contact. Our results suggest that the
role of hotspots in the geospatial spread of TB in rural Ethiopia is
limited, implying that TB transmission is primarily locally driven. spatial_mathematical_modelThe file contains 1) a system of ordinary differential equations used in the model and 2). a model runner that calls the function