BRAZILIAN OVERVIEW OF LEPTOSPIROSIS IN THE LAST 5 YEARS: ECOLOGICAL STUDY

Leptospirosis is a bacterial zoonosis of compulsory notification in Brazil, with transmission associated with exposure to environments contaminated by the urine of infected animals, especially rodents. Factors such as heavy rainfall, flooding and poor sanitation contribute to its spread, particularly in vulnerable urban areas. Given the increasing frequency of extreme weather events, it is necessary to monitor the distribution and temporal behavior of the disease to support public policies for prevention and control. This study aimed to analyze confirmed cases of leptospirosis in Brazil. Observational, ecological and retrospective study based on secondary data from the Notifiable Diseases Information System (SINAN), obtained via DATASUS. All confirmed cases of leptospirosis notified in Brazil between 2020 and 2024 were included and stratified by macro–geographic region. Data were organized by year of notification and summed for each region and for the national total. Temporal trends were assessed by simple linear regression, adopting a 5% significance level (p<0.05). A total of 12,013 confirmed cases of leptospirosis were recorded in Brazil between 2020 and 2024. Linear regression indicated an average increase of 175.6 cases per year (R² = 0.13; p=0.558), without statistical significance, indicating the absence of a consistent linear trend. The highest concentrations occurred in the South (4,015) and Southeast (3,820) regions, while the Center-West region had the lowest number of cases (234), demonstrating uneven geographic distribution of the disease. The study showed a heterogeneous distribution of leptospirosis in Brazil between 2020 and 2024, with predominance in the South and Southeast regions. Although there was an absolute increase in cases, no statistically significant trend was observed. The findings reinforce the need for region-specific strategies to tackle the disease, involving environmental monitoring, vector control, improvements in basic sanitation and strengthening of epidemiological surveillance, especially in contexts of social and environmental vulnerability.