First outbreak of autochthonous “surra” in horses in Santa Catarina State, Brazil: Parasitological, hematological and biochemical characteristics.

The article describes the first local outbreak of “surra” in horses in the Santa Catarina State of Brazil. It studies the infection’s effect on horses from a parasitological, hematological, and biochemical perspective, including the recovery process.

Study Context and Methods

• The examined event represents the first time the surra disease, caused by the Trypanosoma evansi parasite, was identified among horses in the Santa Catarina State in southern Brazil.
• Six horses showing symptoms of trypanosomosis, the disease caused by the parasite, were confirmed to be infected using PCR (polymerase chain reaction) and rapid serum agglutination test.
• The research carried out initial observations (T0) to identify the clinical symptoms and abnormal biochemical parameters in the infected horses.
• A subsequent observation was conducted 90 days later (T1) to monitor the recovery process and changes in the health conditions of the horses.

Initial Findings (T0)

• All of the tested horses demonstrated severe clinical signs related to the T. evansi infection.
• The horses’ hematological and serum biochemical parameters, including hematocrit, leukocyte count, platelet count, hemoglobin levels, and levels of biochemicals like ALT, CPK, LDH, creatinine, bilirubin, and glucose, were out of normal range, indicating significant physiological changes caused by the disease.

Follow-up Findings (T1)

• 90 days after the initial observation, the horses showed progressive clinical recovery.
• The previously abnormal hemato-biochemical parameters had returned close to normal ranges, and PCR results for T. evansi came back negative, suggesting healing from the infection.

Implications and Recommendations

• The study could not identify the particular vector or transmission mechanism through which the horses were infected.
• Given this, the researchers suggest implementing surveillance and control measures to prevent the spread of the disease among horses, and potentially to other animal species, in the Santa Catarina State.