Virus de la leucosis bovina (VLB) y evidencias de su potencial zoonótico

Abstract

Bovine Leukemia Virus (BLV) is a retrovirus with oncogenic potential which causes persistent infections in cattle, leading to chronic lymphocytosis processes, which could evolve into leukemias and/or lymphomas in advanced stages of the disease in cattle. In recent decades, this virus has aroused interest in the scientific community due to different studies reporting evidence of the provirus in humans, and its proposal as a potential risk factor for breast cancer development. However, its transmission pathway to humans remains uncertain, but it is suggested that it could be a zoonotic infection due to the increase of potential contact interfaces between animals and humans. Likewise, the virus has been found in multiple animal species, which proposes it as a versatile agent with a high potential for dissemination in its natural environment. Due to the difficulty in the diagnosis in the veterinary field, as well as the lack of vaccines, an increase in the prevalence rates of the virus has been reported worldwide, what makes the virus to remain unnoticed in animal populations, increasing the rates of propagation and dissemination. In this PhD research, it was proposed a study focused on the detection of the virus in Colombian women as well as in different animal species to provide evidence of the zoonotic potential of the virus and to contribute to the current knowledge of BLV in Colombia. A case-control study was carried out to identify whether the virus was associated with breast cancer in a population of Colombian women, and progress was made in the characterization of the zoonotic potential of the virus by evaluating shared biological markers between animal species and humans, and by experimental approaches to the virus's infection capacity in human cells and its potential cellular receptor. Although it is still necessary to carry out more studies to fully understand the impact of BLV in humans, the results obtained in this research contributed to the knowledge of the virus in the country by providing updates in the current status of BLV in Colombia, in terms of its prevalence rates in the Colombian cattle, identification of the virus as a potential risk factor for breast cancer development in Colombian women, and giving advances in the knowledge of its zoonotic potential approached from the principles of zoonotic infections, including the identification of accidental hosts, identification of shared biological markers between species, identification of potential dissemination routes and experimental evidence of the infection in humans.