One Health assessment of zoonotic intestinal parasites in humans, dogs, and soil of coastal Cartagena, Colombia.

Background and Aim: Zoonotic intestinal parasites remain a neglected public health problem in low-resource coastal communities where humans, free-roaming dogs, and contaminated environments interact closely. Cartagena, Colombia, lacks updated epidemiological data on intestinal parasitosis despite its high tourist influx and vulnerable populations. This study applied a One Health framework to investigate the prevalence of intestinal parasites in humans, dogs, and soil in two coastal regions of Cartagena (La Boquilla and Punta Arenas) and to identify associated risk factors and clinical manifestations. Materials and Methods: A cross-sectional survey was conducted between March 2024 and March 2025. Stool samples from 33 residents and 42 dogs were analyzed by direct microscopy with saline and Lugol's solutions, while 78 soil samples were assessed using the Krumbein, Sloss, and Willis techniques. Dogs suspected of Results: Soil samples showed high contamination with Conclusion: This One Health investigation highlights significant zoonotic risk from shared parasitic infections in humans, dogs, and contaminated soils in Cartagena's coastal regions. The lack of systematic deworming and vaccination in dogs, poor sanitation, and close human-dog contact amplify transmission. Strengths of this study include its integrative human-animal-environment approach, while limitations involve modest sample size and lack of molecular genotyping. Future work should apply molecular epidemiology to confirm cross-species transmission. Practical implications emphasize the urgent need for mass deworming campaigns, improved waste management, vector control, and public health education to reduce zoonotic intestinal parasite burden in vulnerable coastal communities.