Bovine leukemia virus: an emerging concern for zoonotic cross-species transmission.

Bovine leukemia virus (BLV) is a retrovirus that causes leukemia-like disorders in cattle and sheep, as well as inflammatory conditions and reduced milk production in dairy cows, leading to substantial economic losses in the global cattle industry. BLV infection is widely prevalent among cattle populations worldwide. Emerging evidence has indicated a potential association between BLV infection and human breast cancer development. In several regions, BLV DNA has been detected in human breast tissue samples, particularly in tumor cells, suggesting that BLV may contribute to the development of breast cancer. This review summarizes recent advances in research on the possible link between BLV and human breast cancer, emphasizing its potential public health significance. Furthermore, we examine progress in the development of preventive vaccines, which may play a crucial role in mitigating BLV transmission.