Hossein Barzeghar - Department of Microbiology and Virology, School of Medicine, Zanjan University of Medical Sciences, Zanjan, Iran
Hessam Mirshahabi - Department of Microbiology and Virology, School of Medicine, Zanjan University of Medical Sciences, Zanjan, Iran
Nima Motamed - Department of Social Medicine, School of Medicine, Zanjan University of Medical Sciences, Zanjan, Iran
Massoud Yavarmanesh - Department of Food science and Technology, Ferdowsi University of Mashhad, Mashhad, Iran
Behroz Mahdavi Poor - Department of Laboratory Sciences, Faculty of Paramedicine, Tabriz University of Medical Sciences, Tabriz, Iran
Seyyed Reza Moaddab - Department of Laboratory Sciences, Faculty of Paramedicine, Tabriz University of Medical Sciences, Tabriz, Iran
Mohammad Asgharzadeh - Hematology and Oncology Research Center, Faculty of Paramedicine, Tabriz University of Medical Sciences, Tabriz, Iran

Bovine leukemiavirus (BLV) is one of the most important carcinogenic viruses genetically related to the human T-cell lymphotropic viruses (HTLV-۱ and HTLV-۲). The virus infects type B lymphocytes and creates lymph glands tumors. Recently, the association between the presence of this virus and breast cancer has been addressed in humans. Here, we studied the prevalence of BLV in the samples of raw milk of native Iranian and Iranian-foreign cows in traditional, semi-industrial and industrial dairy farms in rural and urban areas of Zanjan province. Raw milk samples of cows were collected manually in sterile tubes. The samples were tested by nested-PCR method. Forty samples (۹.۹۳%) out of ۴۰۳ samples showed BLV contamination. In this study, nested-PCR was successfully applied to determine the level of contamination in raw milk samples from cows infected with BLV. Furthermore, a relatively high rate of BLV infection was found in dairy cows in Zanjan province, northwestern of Iran.

Bovine leukemia virus, Breast cancer, Milk, Nested-PCR