Diagnostic approaches for tick-borne haemoparasitic diseases in livestock

Abstract

Tick-borne diseases (TBDs) are a major economic constraint to livestock production affecting the productivity of livestock worldwide. Identification of these haemoprotozan and rickettsial infections is essential in understanding the epidemiology and it is important to distinguish between species and subspecies involved. Conventional techniques including serological and microscopic examinations do not always meet these requirements. Clinical diagnostic and surveillance tools, such as the complement fixation test (CFT), the indirect fluorescent antibody test (IFAT) and the enzyme linked immunosorbent assay (ELISA) have been successfully used over decades. In addition, DNA-based tests for diagnosis, differentiation and characterisation of different haemoparasites have been developed. Molecular diagnostic techniques, such as DNA hybridization and polymerase chain reaction (PCR), allow detection of parasites in blood, tissue or ticks with high levels of sensitivity, specificity and reliability. In addition, some techniques can identify multiple pathogens in the same samples. Furthermore, these techniques can also be exploited to identify unambiguous species and subspecies. Under the precondition that these tests are correctly designed and validated, they provide a powerful tool for epidemiology, with greater advantages of affordability and amenability to standardization. The implementation of these techniques for studying TBDs worldwide will be invaluable. Thus, the aim of this study is to put together the details of the techniques in the form of small review consultation of the practitioners and researchers.