Diagnosis of Babesia equi in horses belonging to resource-poor farmers in the northeastern Free State, South Africa
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Date
2005-10
Authors
Motloang, Makhosazana Yvonne
Journal Title
Journal ISSN
Volume Title
Publisher
University of the Free State
Abstract
Babesia (Theileria) equi, a tick transmitted protozoan parasite and one of the causative organisms of equine babesiosis is widespread in South Africa. This work reports on a study that evaluated the usefulness of the polymerase chain reaction (PCR) for detection of B. (Theileria) equi in horses belonging to resource-poor farmers in the northeastern Free State, South Africa. Blood samples from a total of 99 horses and seven from previously known B. (Theileria) equi infected horses on Kaai plaas farm (Onderstepoort Veterinary Institute) were examined for the presences of B. (Theileria) equi using Giemsa-stained blood smears, immunofluorescent antibody test (IF AT) and PCR technique. Giemsa-stained blood smears and serum samples were prepared from blood samples on arrival at the university laboratory. Aliquots of blood samples from EDT A coated vacutainers were transferred into marked cryogenic vials and stored at -35°C for further use in PCR. A PCR system that amplifies a 664 bp target of region of the l 6S rRNA gene and shown to specifically detect the genome of B. (Theileria) equi, was· used in this study. Examination of the 99 blood smears from the northeastern Free State revealed no parasites whilst serological analysis showed 98% of animals were seropositive for B. (Theileria) equi, 48% were seropositive for B. caballi and 58% had mixed infections for both Babesia species. However, PCR was negative for all the 99 horses from the northeastern Free State. Babesia equi parasites were demonstrated in blood smears from 4 out of 7 horses from the Kaai plaas farm. All these animals were also seropositive for B. (Theileria) equi while 3 out of 7 were seropositive for B. caballi. Three out of seven horses were seropositive for both B. (Thei/eria) equi and B. caballi. All seven Kaai plaas farm horses were PCR positive for B. (Theileria) equi infection. Questionnaire results indicated that 100% of resource-poor black farmers in the northeastern Free State did not know about equine babesiosis, its cause, symptoms, diagnosis or control. Based on the negative blood smears and PCR results, and the high prevalence of antibodies against B. (Theileria) equi as demonstrated by IF AT, the conclusion drawn from this study is that the status of equine babesiosis in the northeastern Free state region is endemically stable.
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Keywords
Dissertation (M.Sc. (Zoology and Entomology))--University of the Free State (Qwaqwa Campus), 2005, Horses -- South Africa -- Free State, Veterinary parasitology -- South Africa -- Free State, Babesiosis in horses -- South Africa -- Free State