ATTEMPT TO ERADICATE BOVINE LEUKEMIA VIRUS-INFECTED CATTLE FROM HERDS

The bovine leukemia virus (BL V) is accepted universally as the causative agent of the enzootic from of bovine lymphosarcoma, a fatal neoplastic disease, and persistent lymphocytosis, usually a bening condition that is common in BL V-infected herds2). Although BLV is transmitted both vertically and horizontally3,1l), the latter is the predominant mode in field conditions 1,12). Evidence implicates the involvement of a blood-sucking vector 1, 14). Since practically all BL V-infected cattle possess a specific antibody to the virion glycoprotein antigen of the virus, several serological methods have been described for the detection of BL V antibodies in sera, such as the agar gel immunodiffusion (AGID) test9,12,20) and enzyme-linked immunosorbent assay (ELISA)5,18,21). Immunologically, it was reported that the complement-dependent anti-body cytotoxicity (CDAC) test for peripheral blood lymphocytes using monoclonal antibodies against tumor-associated antigen (T AA) might be useful in the diagnosis of enzootic bovine lymphosarcoma13). The most important principle in an eradication program is the elimination or segregation of infected cattle4,19). Successful results using this idea have been reported6, 10, 15, 17,22)