Submitted to: United States Animal Health Association Proceedings
Publication Type: Proceedings
Publication Acceptance Date: November 4, 1994
Publication Date: N/A
Technical Abstract: The bovine immunodeficiency-like virus (BIV) is a lentivirus in the retrovirus family. BIV is related to other lentiviruses and has tat and rev nonstructural regulatory genes. BIV causes a persistent viral infection in cattle. Infected cattle generally develop an antibody response 3 to 4 weeks after infection, but virus can be isolated in experimental infections from blood samples often as early as 1 week post- inoculation (p.i.) and proviral DNA can be detected as early as 3 days p.i. from blood samples. BIV often causes a transient mononuclear cell increase, mainly a B cell expansion, early in infection. BIV has often been stated to cause, immunodeficiency, lymphadenopathy and encephalitis, but this has not been clearly demonstrated in experimental studies. An ideal method of detection for BIV has not been definitively found, but an ELISA screening test with a Western blot test for confirmation has been suggested. BIV appears to be very widespread in the cattle population, bu a true prevalence of infection has not been determined in the U.S. Most research on BIV has been done with the original R29 isolate. This isolate is thought to be attenuated, and caution must be used when interpreting studies that used this isolate. One study has suggested a link between lower milk production and BIV infection. Experimental studies with BIV have not established a specific disease that it might cause, but further studies are warranted to determine what role BIV may have in disease.