Trypanosoma evansi in Brazil: first evidence of infection in equines from Northeast region

The hemoprotozoan Trypanosoma evansi is a parasite that infects mammals, causing an infection known as trypanosomiasis. There is no report of T. evansi in horses in the State of Maranhão, highlighting the need to assess exposure and infection by the parasite and generate data for its monitoring. The objectives of this study were to identify T. evansi in blood samples from horses, investigate its occurrence in horses in this region, and analyze the associated risk factors. Three hundred blood samples were collected for parasitological (blood smear), serological (indirect enzyme-linked immunosorbent assay - ELISA), and molecular (polymerase chain reaction - PCR) diagnostic purposes. No trypomastigote forms of T. evansi were observed in the examined blood smears. Serological examined of 209 samples revealed that 33.01% (69/209) were positive for anti-T. evansi antibodies. No variable was identified as a risk factor. Among the 300 samples submitted to PCR, 1% (3/300) were positive, and sequencing showed 100% similarity with T. evansi species. The study identified exposure and infection of horses by T. evansi in Maranhão, expanding its geographic distribution in the country and highlighting the importance of periodic testing.