RESUMEN
Monitoring wildlife health is essential for understanding global disease patterns, particularly as vector-borne infections extend the geographic ranges and thereby hosts due to environmental shifts. Anaplasma marginale, primarily impacting cattle, has economic implications and has been found in diverse hosts, yet its presence in capybaras (Hydrochoerus hydrochaeris), influential in tick-borne pathogen spread, lacks comprehensive understanding. From 2015 to 2022, 14 capybaras were surveyed across two different areas of northeastern Argentina. In 1 of 14 (7%) capybaras, the presence of A. marginale was confirmed through the amplification of specific genes, msp5 and msp1ß. In addition, A. marginale DNA was detected in the capybara's blood sample through quantitative PCR, with a cycle threshold value of 30.81 (800 copies per reaction). Amplification of a fragment of the msp1α gene revealed PCR products of three different sizes, suggesting the presence of at least three coinfecting A. marginale variants in the capybara host. This study suggests that capybaras are wild hosts for A. marginale in the Ibera Wetlands in Argentina, potentially influencing the infection dynamics of both domestic and wild species. This finding highlights the necessity for thorough studies on the role of capybaras in disease dynamics, crucial for understanding wildlife health and the spread of disease.