Evaluation of Indirect Enzyme-Linked Immunosorbent Assay (Elisa) Systems For The

Abstract

African animal trypanosomosis caused by Trypanosoma brucei Plimmer & Bradford 1899, T: congolense Broaden 1904 and T. vivax Ziemann 1905 remains one of the major constraints to health and productivity of cattle and other domestic animals in the tsetse infested areas of Tropical Africa. Owing to its varied clinical. Manifestations, diagnosis of trypanosomosis cannot be based on clinical signs alone (Nantulya 1990). Reliable diagnostic methods are a prelude to understanding the epidemiology of the disease and an important consideration when assessing the success of trypanosomosis control programmes. Conventional parasitological methods have a limited sensitivity and may lead to under-estimation of the prevalence of the disease (Paris et a/. 1982) More sensitive' diagnostic tests, including those for the detection of Trypanosoma specific antibodies (Luckins 1977) and antigens (Rae and Luckins, 1984; f'.iantulya et a/. 1992) have therefore been developed. Recently, four indirect ELiSAs have been developed, and their robustness and diagnostic performance evaluated (Rebeski et a/. 2000 a, b). One of the problems that has characterised users of the IAEA ELISA kits for bovine trypanosomosis has been that of maintaining the stability of the antigen during shipment to counterpart laboratories. This study utilised antigen pre-coated plates as a way to try and circumvent the problem. This paper reports on the validation of four indirect ELISA systems using antigen pre-coated polystyrene microplates. The usefulness of the current version of indirect ELISA as an epidemiological tool for studies in bovine trypanosomosis is discussed.