Spatial Distribution of Leprosy in Urban Areas: Systematic Review of Environmental and Social Determinants (2015-2024)

Leprosy remains a relevant public health problem in Brazil and other endemic countries, reflecting deep social and environmental inequalities. This systematic review, conducted according to PRISMA 2020 guidelines (PROSPERO registration CRD420251129311), analyzed studies published between 2015 and 2024 that investigated the spatial distribution of leprosy in urban areas. A total of 44 studies were included, mostly conducted in Brazil, complemented by research in India, Indonesia, Bangladesh, Madagascar, and Nigeria. Most studies adopted ecological design and applied techniques such as Morans I, SaTScan, Bayesian estimators, Kernel density, and spatial regressions. Results revealed persistent clusters in urban peripheries, particularly in Northern and Northeastern Brazil, as well as a consistent association between leprosy and low income, low education, social inequality, and poor sanitation. International studies confirmed similar patterns in contexts of urban poverty. Methodological appraisal showed that 88.6% of the studies were of high quality. In conclusion, leprosy remains strongly associated with socio-environmental determinants, and spatial analysis is a strategic tool for surveillance and the targeting of public health interventions. This study reinforces the relevance of actions aligned with the Sustainable Development Goals (SDGs), particularly SDG 3 (Good Health and Well-being), SDG 6 (Clean Water and Sanitation), and SDG 10 (Reduced Inequalities), which are crucial for addressing the disease. Author summaryLeprosy remains a serious public health issue in Brazil and other endemic countries, often tied to social and environmental inequalities. We conducted a comprehensive review of 44 studies published between 2015 and 2024 to understand the spatial distribution of leprosy in urban areas. We found that the disease doesnt spread randomly; it consistently clusters in vulnerable, peripheral neighborhoods. Our analysis confirms a strong link between leprosy and key socioeconomic factors like low income, poor education, and inadequate sanitation. The presence of new cases in children signals ongoing active transmission within these communities. The findings highlight that fighting leprosy requires more than just medical treatment. We must also address the underlying structural inequalities, aligning health efforts with broader social and urban policies, such as those outlined in the Sustainable Development Goals (SDGs). This approach will allow us to create more effective and targeted public health strategies.