University of Tabriz Journal of Zoonotic Diseases 2476-535X 2026 05 02 Detections of Brucella infection in serum samples and aborted fetuses of small ruminants in East Azerbaijan province (northwest Iran) 21523 10.22034/jzd.2026.21523 EN Yaser Jafari Khataylou Department of Pathobiology, Faculty of Veterinary Medicine, University of Tabriz, Tabriz, Iran Monireh Khordadmehr Department of Pathobiology, Faculty of Veterinary Medicine, University of Tabriz, Tabriz, Iran Hassan Sadri Department of Clinical Sciences, Faculty of Veterinary Medicine, University of Tabriz, Tabriz, Iran Jafar Shirazi Veterinary Organization, East Azerbaijan Province, Tabriz, Iran Saeed Babazadeh Veterinary Organization, East Azerbaijan Province, Tabriz, Iran Ali Mosayyebzadeh Department of Pathobiology, Faculty of Veterinary Medicine, University of Tabriz, Tabriz, Iran Farinaz Jigari Asl Department of Pathobiology, Faculty of Veterinary Medicine, University of Tabriz, Tabriz, Iran Saba Eskandari Department of Pathobiology, Faculty of Veterinary Medicine, University of Tabriz, Tabriz, Iran Abolfazl Hajibemani Department of Clinical Sciences, Faculty of Veterinary Medicine, University of Tabriz, Tabriz, Iran Katayoun Nofouzi Department of Pathobiology, Faculty of Veterinary Medicine, University of Tabriz, Tabriz, Iran Journal Article 2026 02 22 Brucellosis, a zoonotic disease caused by <em>Brucella species,</em> results in significant economic losses in both animal production and human health. The aim of the present study was to evaluate the presence of <em>Brucella </em>infection in aborted fetuses and serum samples from adults with history of recent abortion using serological, molecular, and pathological studies in East Azerbaijan Province. A total of 62 aborted fetuses and 373 blood samples were collected from sheep and goat flocks. The conventional PCR method was employed for the detection of <em>Brucella</em> infection following DNA extraction from the abomasal contents of the aborted fetuses. The serum samples from the adults were evaluated using the Rose Bengal Plate Test (RBPT), Wright, and 2-mercaptoethanol (2-ME). Moreover, the formalin-fixed tissue samples from the aborted fetuses were conducted for histopathological examinations. Molecular and serological findings revealed that <em>Brucella</em> infection was present in 88.7% (56 out of 62) of aborted fetuses and 79.09% (272 out of 373) of serum samples. Histopathological studies revealed necrotic and inflammatory responses associated with severe hyperemia and hemorrhagic lesions in the tissue sections, particularly in the brain, lung, liver, and kidney. In conclusion, the detection of <em>Brucella</em> infection in both aborted fetuses and blood samples indicates of its significant role in sheep and goat abortions in East Azerbaijan. More importantly, it remains one of the most common zoonotic diseases worldwide. Therefore, effective management and vaccination strategies are crucial for preventing and controlling the disease from a public health perspective. https://jzd.tabrizu.ac.ir/article_21523_d3d44b75f4710db982f68db65ec2b78a.pdf