Evidence for bovine immunodeficiency virus infection in cattle in Zambia

We report herein on the first evidence for the presence of bovine immu­ nodeficiency virus (BIV) in Zambia. Serological surveillance of BIV and bovine leukemia virus (BLV) was conducted in traditional cattle herds in Zambia. Out of a total of262 sera analyzed, 1l. 4%were found positive for anti-BIV p26 an­ tibodies as determined by Western blot analysis, while 5.0% were positive for anti-BLV gp 51 antibodies as detected by immunodiffusion test. Peripheral blood mononuclear cells from BIV seropositive cattle were found to have BIV­ provirus DNA, as detected by nested polymerase chain reaction. A nucleotide sequence corresponding to a 298 bp fragment of the BIV pol gene was also analyzed. Amino acid sequences of these Zambian pol gene products showed 98.0 to 100% homology to the American strain BIV R29, 97.0 to 99.0% to Japanese BIV isolates, and divergence ranged from 0.0 to 2.0% among Zam­ bian BIV isolates.