Tehran University of Medical Sciences Iranian Journal of Public Health 2251-6085 53 4 2024 04 08 799 808 Mehmet Çelik Department of Infectious Diseases and Clinical Microbiology, Faculty of Medicine, University of Harran, Şanlıurfa, Turkey Yeliz Çiçek Department of Infectious Diseases and Clinical Microbiology, Bingol State Hospital, Bingol, Turkey Ebru Atalay Department of Infectious Diseases and Clinical Microbiology, Cizre Dr. Selahattin Cizrelioğlu State Hospital, Şırnak, Turkey Deniz Altındağ Department of Infectious Diseases and Clinical Microbiology, Cizre Dr. Selahattin Cizrelioğlu State Hospital, Şırnak, Turkey Fethiye Akgül Department of Infectious Diseases and Clinical Microbiology, Batman Training and Research Hospital, Batman, Turkey Fatma Ürkmez Department of Infectious Diseases and Clinical Microbiology, Kırıkkale Yüksek İhtisas Hospital, Kırıkkale, Turkey Esra Gürbüz Department of Infectious Diseases and Clinical Microbiology, SBU Van Training and Research Hospital, Van, Turkey Ahmet Şahin Department of Infectious Diseases and Clinical Microbiology, Dr. Ersin Arslan Training and Research Hospital, Gaziantep, Turkey Sevda Özdemir Al Department of Infectious Disease and Clinical Microbiology, Turhal State Hospital, Tokat, Turkey Seval Bilgiç Atlı Department of Infectious Disease and Clinical Microbiology, Turhal State Hospital, Tokat, Turkey Sevil Alkan Department of Infectious Diseases and Clinical Microbiology,Faculty of Medicine,University of Canakkale Onsekiz Mart,Canakkale, Turkey Davut İpek Department of Infectious Diseases and Clinical Microbiology, Mardin Training and Research Hospital, Mardin, Turkey Serpil Oğuz Mızrakçı Department of Infectious Diseases and Clinical Microbiology, Gaziantep LIV Hospital, Gaziantep, Turkey Mehmet Reşat Ceylan Department of Infectious Diseases and Clinical Microbiology, Faculty of Medicine, University of Harran, Şanlıurfa, Turkey Pınar Yürük Atasoy Department of Infectious Diseases and Clinical Microbiology, Ankara City Hospital, Ankara, Turkey Mustafa Kasım Karahocagil Department of Infectious Diseases and Clinical Microbiology, Faculty of Medicine, University of Kırşehir Ahi Evran, Kırşehir, Van, Türkiye 2023 05 02 2023 09 28 Background: Brucellosis is one of the most common zoonotic infections. Although culture is the gold standard diagnostic method, bacterial growth in blood cultures may not always occur due to various factors. We aimed to investigate demographic, clinical, and laboratory findings that may have predictive significance for bacteremia in brucellosis. Methods: Patients older than 18 years of age followed up with a diagnosis of brucellosis between 2012 and 2022 were included in this retrospective multicenter study. They were divided into two main subgroups according to their Brucella species reproductive status as bacteremic and non-bacteremic. Results: A total of 743 patients, 370 (49.80%) bacteremic and 373 (50.20%) non-bacteremic brucellosis patients, were enrolled. The mean age of the bacteremic group (36.74 years) was lower than the non-bacteremic group (43.18 yr). High fever, chills/cold, sweating, nausea, vomiting, and weight loss were more common in the bacteremic group. In the bacteremic group, white blood cell count, platelet count, hemoglobin level, mean platelet volume, eosinophil, and neutrophil counts were lower, and lymphocyte, erythrocyte sedimentation rate, aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase, and ferritin levels were higher. According to the receiver operating characteristic (ROC) analysis, when the cut-off value of ferritin was considered 67, it was the parameter with the strongest predictive significance in Brucella bacteremia. Conclusion: High ferritin level, low eosinophil count, and increased erythrocyte sedimentation rate were determined as the most critical laboratory findings in predicting bacteremia in brucellosis. https://ijph.tums.ac.ir/index.php/ijph/article/view/31912 https://ijph.tums.ac.ir/index.php/ijph/article/download/31912/8208