Distribution and prevalence of human leptospirosis in South America: a systematic review of the last 15 years

Leptospirosis is a neglected zoonotic disease with a high burden in South America, particularly in tropical regions where environmental and socioeconomic factors facilitate transmission. This systematic review synthesizes evidence on the distribution, prevalence, and risk factors of human leptospirosis across South American countries from 2010 to 2025, following PRISMA guidelines. A comprehensive search across seven databases identified observational studies reporting epidemiological data, with findings revealing a heterogeneous distribution, with Brazil, Colombia, and Peru as hotspots. Key drivers include heavy rainfall, flooding, poor sanitation, and occupational exposure, particularly among marginalized urban and rural populations. Diagnostic challenges, underreporting, and fragmented surveillance systems further complicate disease control. The review highlights the need for integrated interventions—combining improved diagnostics, rodent control, sanitation, and health education—alongside policies addressing social determinants of health. Future research should prioritize standardized methodologies, One Health approaches, and climate-resilient strategies to mitigate leptospirosis in the region.