Detection of Trypanosoma evansi in healthy horses, cattle and buffaloes in East Sumba: eight years after outbreak

Abstract

Trypanosoma evansi is a widespread hemoflagellate parasite that causes surra (trypanosomiasis) in a variety of mammal species, including horses, cattle, and buffaloes. In 2010-2012, the greatest outbreak of surra in Indonesia occurred on one of Indonesia’s most remote islands, Sumba. This parasite has killed thousands of animals, particularly horses. The purpose of this study was to determine the prevalence of T. evansi infection in healthy livestock (buffaloes, cattle, and horses) after the 8th outbreak in East Sumba using different methods, including serological test (CATT/T. evansi), parasitological test (WBF, Giemsa-stained blood smears (GSBS), and Microhematocrit Centrifugation Test (MHCT), and molecular method by PCR. The survey was conducted during the arid season, when the population of vectors was at its lowest. Blood samples were taken from 111 animals in three subdistricts in East Sumba (Lewa, Wulla Waijelu, and Kota Waingapu). Results revealed that the infection rate of livestock with T. evansi varies by animal species and detection methods. No positive sampel found by Micro Hematocrit Centrifugation Test (MHCT), wet blood film (WBF), and Giemza-stained blood smears (GSBS). The overall infection prevalence according CATT/T.evansi and PCR were 7.2%(8/111) and 5.4% (6/111); respectively. The infection rates by CATT T.evansi and PCR were as follows: horse, 0/57 (0%) and 1/57(1.75%); buffalo 5/23 (21.7%) and 13.04% (3/23); cattle, 3/31 (9.7%) and 2/31(6.45%); respectively. Buffalo and cattle have a higher prevalence of T. evansi compared to horses. The results of the present study indicate that cattle and buffalo may serve as a reservoir for T. evansi, which poses a high risk to horses due to the virulence of Surra when vector populations are abundant.

Parasitological and serological detection of Trypanosoma evansi on Bali cattle at the Pesanggaran slaughterhouse, Denpasar, Indonesia using hematological profile

“…A low prevalence of T. evansi in healthy cattle was also reported in East Sumba, Indonesia, eight years after the surra outbreak in Sumba Island. The infection rates by CATT T. evansi were 9.7% (3/31), and by GSBS, 0% (0/31) (Sawitri and Wardhana 2024). Likewise, in South Sulawesi, Indonesia, only one out of 100 cattle tested positive for T. evansi using microscopic observation, but PCR analysis revealed a higher prevalence of 3%.…”

“…evansi) based on RoTat 1.2 (OIE 2021). The CATT is a serological test to detect antibodies and is the best test for detecting T. evansi in buffalo in Indonesia (Reid 2002;Ekawasti et al 2016;Sawitri and Wardhana 2024). CATT is relatively cheap, fast, and simple and can be implemented in the field for any host (Desquesnes et al 2022).…”

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

“…The incubation period of Surra in horses is 1-4 weeks followed by common but not specific clinical signs such as fluctuating fever, weakness, lethargy, anemia, severe weight loss, petechial hemorrhages sometime with nervous signs which are different from one host and one place to another associated with its immunosuppressive effects (Desquesnes et al 2013;Wardhana and Savitri 2018). The grates catastrophic outbreak of Surra in Sumba Island, as the largest source of horse breeding in Indonesia, was reported during 2010-2012 causing more than 2000 animal death, primarily horses followed by cattle (Sawitri and Wardhana 2024). This condition was very detrimental to horse breeders from economic and cultural aspects (Anggung et al 2019).…”