Authors : Carlos Souto dos Santos Filho, Ana Júlia Alves Câmara, Guilherme Aparecido Santos Aguilar
DOI : 10.47276/lr.97.2.2025107
Volume : 97
Issue : 2
Year : 2026
Page No : 1-15
Objectives Leprosy remains a significant public health challenge in Brazil, with distinct spatial and temporal patterns reflecting underlying socioeconomic inequalities. This study investigated the association between municipal socio-territorial indicators and the geographic distribution of leprosy in São Paulo State. Methods A total of 4562 new leprosy cases reported across 645 municipalities from 2017 to 2020 were analysed using Bayesian spatial modelling. The Besag–York–Mollié 2 (BYM2) model was implemented to estimate relative risk while accounting for spatial dependence, incorporating municipal wealth as a covariate. Expected case counts were calculated based on overall state incidence rates and local population sizes. Exceedance probabilities were computed to identify high-risk clusters using a threshold of relative risk >2.0. Results Local relative risk estimates ranged from 0.06 to 31.52 (median: 0.96), with substantial spatial heterogeneity across municipalities. Municipal wealth demonstrated a significant protective effect (posterior mean: –0.059, 95% CrI: –0.081 to –0.037), indicating lower leprosy incidence in economically advantaged areas. The mixing parameter (φ = 0.517) revealed approximately equal contributions of structured spatial and unstructured random effects. High-risk clusters were predominantly concentrated in western and northern regions of the state. Conclusions Leprosy distribution in São Paulo State exhibits significant spatial clustering associated with municipal wealth disparities. The persistent geographic patterns suggest that socioeconomic conditions are associated with variations in local leprosy risk across municipalities. These findings support targeted public health interventions in identified high-risk areas and highlight the importance of addressing underlying sociodemographic inequalities that may influence the local effectiveness of leprosy control strategies.