When science remembers what is neglected: addressing the risks of rodent-borne diseases in urban Latin America.

Latin American cities face deep socio-economic inequalities that impact health, education and the environment. These disparities influence zoonotic disease dynamics through complex host-pathogen-environment-human interactions. This study explores zoonotic risks associated with rodent communities across diverse social and environmental settings in the Matanza-Riachuelo River Basin, one of the most polluted urban areas in Buenos Aires, Argentina. Between 2022 and 2023, rodent community composition and health status were assessed at 22 sites, ranging from low-income neighbourhoods to green areas along an urbanization gradient. A total of 366 rodents-comprising three synanthropic and four native species-were captured and tested for leptospirosis, Orthohantavirus, SARS-CoV-2 and zoonotic helminths. Rodent community structure reflected local environmental conditions: wild species dominated low-disturbance areas, while synanthropic species, especially Rattus norvegicus, prevailed in densely populated sites lacking basic urban services and hosted the highest pathogen richness. Pathogen presence was spatially heterogeneous and strongly linked to infrastructural deficiencies, underscoring the role of poor urban planning in the emergence of rodent-borne diseases. Findings informed the development of educational and training programmes to prevent zoonoses. Grounded in the One Health framework, this study emphasizes the interconnectedness of human, animal and environmental health, and the need for transdisciplinary strategies in neglected urban areas.