Understanding the Epidemiology of Trypanosoma Evansi Infection in Dogs (Canis lupus familiaris) from Urban Areas of Colombia

Trypanosomaevansi is a protozoan parasite that is the causative agent of the animal disease known as "surra", which affects a wide variety of wild and domestic mammals including humans. This study aimed to evaluate the molecular point prevalence and clinic-epidemiological traits of T. evansi infection in dogs from municipalities of the Metropolitan Area of Bucaramanga (MAB), Santander, Colombia. From 2019 and 2020, a cross-sectional study in four municipalities of MAB was carried out to evaluate the above features in 213 healthy dogs from these cities. Molecular analysis using the primer ESAG/6 and ESAG/7, showed a T. evansi frequency of 1.8% (CI 95% = 0.04-3.68%), while Woo test didn't detect positive animals. A high prevalence of infection was detected in Piedecuesta (10.53%) and Bucaramanga (1.65%), apparently negative animals were detected in Giron and Florida Blanca. Clinical characteristics revealed that all positive animals (4/4) showed low Mean Corpuscular Hemoglobin (MCH) and (3/4) low Mean Corpuscular Volume (MCV), and one animal had a moderate fever with prolonged capillary refill time. The epidemiological characteristics showed that all animals received mixed food, (3/4) came from low socio-economic areas, and (2/4) from neighborhoods without weekly garbage collection. In conclusion, molecular methods detected a considerable prevalence of animals chronically infected by T. evansi in MAB, with more frequency in neighborhoods of a low socio-economic level where animals have more risk of oral transmission. These results should be considered during urban control programs of surra in MAB.