The Global Epidemiology of Bovine Leukemia Virus: Current Trends and Future Implications

Simple Summary Bovine leukemia virus (BLV) is the causative agent of enzootic bovine leukosis (EBL), which is the most significant neoplastic disease in cattle. EBL is often overlooked in daily breeding processes due to the absence of obvious clinical symptoms. However, studies have revealed that EBL can severely impact the production performance of dairy cows, leading to a substantial economic burden on the cattle industry. In recent years, the global prevalence of EBL has been on the rise, and fragments of BLV nucleic acid have been detected in human breast cancer patients, raising public concerns. Due to the absence of an effective vaccine, controlling the disease is challenging. This review aims to provide a comprehensive overview of BLV, including its role in causing EBL, the genome of BLV, its current prevalence, transmission routes, clinical symptoms, detection methods, hazards, control strategies, and the current state of BLV research. The primary objective of this review is to offer breeders and researchers reliable veterinary knowledge on BLV and identify future research directions in this field.Abstract Bovine leukemia virus (BLV) is a retrovirus that causes enzootic bovine leucosis (EBL), which is the most significant neoplastic disease in cattle. Although EBL has been successfully eradicated in most European countries, infections continue to rise in Argentina, Brazil, Canada, Japan, and the United States. BLV imposes a substantial economic burden on the cattle industry, particularly in dairy farming, as it leads to a decline in animal production performance and increases the risk of disease. Moreover, trade restrictions on diseased animals and products between countries and regions further exacerbate the problem. Recent studies have also identified fragments of BLV nucleic acid in human breast cancer tissues, raising concerns for public health. Due to the absence of an effective vaccine, controlling the disease is challenging. Therefore, it is crucial to accurately detect and diagnose BLV at an early stage to control its spread and minimize economic losses. This review provides a comprehensive examination of BLV, encompassing its genomic structure, epidemiology, modes of transmission, clinical symptoms, detection methods, hazards, and control strategies. The aim is to provide strategic information for future BLV research.