The Epidemiological Scenario of Human Leptospirosis in Brazil from 2015 to 2024

Background: Leptospirosis is a neglected tropical disease with substantial public health impact in Brazil, closely associated with socio-environmental vulnerabilities and climatic extremes. This study analyzed the epidemiological profile and spatiotemporal distribution of leptospirosis incidence and lethality rates in Brazil from 2015 to 2024. Methods: An ecological time-series study was conducted using secondary data from the Notifiable Diseases Information System (SINAN). Variables included geographic region, probable infection environment, and occupational and educational level (ISCED-2011). Results: A total of 31,397 cases were notified, with an annual average of 3140 cases. The South and North regions exhibited the highest incidence rates, while the Northeast and Southeast presented lethality rates above the national average (9.20%). A marked reduction in notifications occurred during the COVID-19 pandemic. Infections occurred predominantly in the domiciliary environment (64%). Rural workers (27.45%) and civil construction workers (18.63%) were the most affected occupational groups, with a higher incidence rate among illiterate and low-education populations. Conclusions: The dynamics of leptospirosis in Brazil are complex and multifactorial, influenced by climatic variations and driven by deficits in basic sanitation and education level. Mitigating the disease burden requires sustained, region-specific public health strategies, targeted infrastructure improvements, and enhanced epidemiological surveillance to address underreporting.