The false perception of elimination in states classified as low endemicity masks a complex reality of diagnostic neglect and deficient surveillance. This study aimed to spatially map leprosy distribution in Santa Catarina (2010–2021), correlating epidemiological patterns with municipal social indicators to reveal the disease’s hidden dynamics and identify social determinants that perpetuate its invisibility in supposedly controlled territories. Ecological study with spatial analysis of 2,498 cases notified in SINAN. Crude and smoothed municipal detection rates were calculated, as well as the proportion of cases with grade 2 disability (G2D) at diagnosis as an indicator of late diagnosis. Spatial distribution was assessed using Global and Local Moran indices (LISA) with FDR correction. Spearman correlations evaluated associations between epidemiological variables and social indicators (literacy, housing, health, Family Health Strategy coverage). Thematic maps were produced using QGIS and GeoDa to visualize clusters and silent areas. A total of 2,498 cases were recorded, with an average rate of 0.30/10,000 inhabitants, showing marked spatial heterogeneity. Notably, 25% of municipalities reported no cases, forming suspicious “epidemiological voids”. High-detection clusters were identified in the western region, alongside extensive silent areas in the mountain and southern regions, some with no records for over a decade. Worse housing conditions and higher illiteracy rates correlated significantly with higher incidence of late-diagnosed cases. Municipalities with higher Family Health Strategy coverage had lower disability rates, highlighting the protective role of qualified primary care. Leprosy in Santa Catarina is not a resolved problem but has been systematically neglected. Case concentration in areas with deficient infrastructure and the epidemiological silence of historically hyperendemic municipalities reveal critical surveillance failures and unprepared health services. Spatial mapping goes beyond the delineation of risk boundaries, revealing the fallacy of apparent control. The persistence of hidden transmission urgently demands the implementation of active surveillance and continuing education for healthcare professionals.
Vitiritti et al. (2026) studied this question.