Investigation into Trypanosoma evansi Infection in Horses in East Sumba-Indonesia

Abstract

Trypanosoma evansi (T. evansi) is a blood parasite, the causative agent of Trypanosomiasis (Surra) in many animal species primarily horses. In Indonesia, surra is a major disease of horses causing a catastrophic outbreak in Sumba Island killed thousands of horses during 2010-2012. Diagnosis of the disease is frequently based on parasitological technique. The aims of this study were to investigate T. evansi infection using both serological, parasitological and hematological techniques in horses in East Sumba. A total of 270 blood samples were randomly collected from both sexes of the healthy-looking animals for serum tested with Card Agglutination Test for Trypanosomiasis (CATT), and blood smear for detecting the presence of the parasite and for the leukocyte sub-population respectively. The results showed that 24.81% (67/270) of the samples were positive antibody to T. evansi antigen, and only 2.2% (6/270) of the serologically positive samples were also confirmed positive with the parasite. The leukocytes sub-population of the parasite-positive animals consisted of lymphocytes 60-98% (82.17 ± 14.43%), monocyte 0-4% (1.5 ± 1.76%), neutrophiles 0-40% (16.17±14.57%), eosinophils 0% and basophils 0-1% (0.17±0.41%) respectively. It was concluded that the seroprevalence of investigated animals were almost 25%, 2.2% of them suffered with parasitemia, lymphocytosis and neutropenia. This data suggesting a positive correlation between the applied tests, and it was considered as a novel diagnostic confirmation regarding Surra infection in the region.