Tehran University of Medical Sciences Iranian Journal of Public Health 2251-6085 54 10 2025 11 01 2242 2250 Halil Doru Department of Emergency Medicine, Health Sciences University Erzurum City Hospital, Erzurum, Turkey Orhan Delıce Department of Emergency Medicine, Health Sciences University Erzurum City Hospital, Erzurum, Turkey Furkan Akpınar Department of Emergency Medicine, Health Sciences University Erzurum City Hospital, Erzurum, Turkey Onur Zengın Department of Emergency Medicine, Health Sciences University Erzurum City Hospital, Erzurum, Turkey Sibel Iba Yılmaz Department of Infectious Diseases, Health Sciences University Erzurum City Hospital, Erzurum, Turkey Sinan Yılmaz Department of Public Health, Atatürk University, Erzurum, Turkey 2025 02 22 2025 08 11 Background: Crimean-Congo Hemorrhagic Fever (CCHF) often presents with non-specific flu-like symptoms that resemble upper respiratory tract infections (URTI), especially in endemic areas. We aimed to evaluate whether complete blood count (CBC) parameters could distinguish between CCHF and URTI in emergency settings. Methods: We conducted a retrospective comparative analysis of 503 patients: 203 confirmed CCHF cases and 300 URTI cases. The study was carried out at Erzurum City Hospital, Erzurum, Turkey, between 2023 and 2024. Hematological parameters including WBC, PLT, RDW, MPV, and others were analyzed. ROC analysis was used to evaluate the prognostic value in CCHF patients. Results: Significant differences in multiple CBC parameters were observed between the two groups. CCHF patients had significantly lower WBC, PLT, and lymphocyte counts, and higher MPV and RDW values compared to URTI patients (P-value<0.001). Among CCHF cases, 40.4% were initially misdiagnosed as URTI. ROC analysis indicated moderate prognostic power for HGB and PLT in predicting mortality. Conclusion: CBC parameters can assist in distinguishing CCHF from URTI in endemic areas, especially when RT-PCR is unavailable. Emergency physicians should consider CCHF in differential diagnosis when specific hematological abnormalities are present.  https://ijph.tums.ac.ir/index.php/ijph/article/view/38265 https://ijph.tums.ac.ir/index.php/ijph/article/download/38265/8682