Clinical and Laboratory Factors Associated with Mortality in Crimean-Congo Emorrhagic Fever: A Retrospective Study of 100 PCR-Confirmed Cases in Nasiriyah, Iraq

Abstract

Background: Crimean-Congo hemorrhagic fever (CCHF) is a severe tick-borne viral zoonosis that can progress to hemorrhage, multiorgan dysfunction, and death. Local data on clinical and laboratory correlates of fatal outcome remain limited.

Objective: To describe the clinical and laboratory profile of PCR-confirmed CCHF and identify factors associated with in-hospital mortality in patients treated at a tertiary hospital in Nasiriyah, Iraq.

Methods: This retrospective observational study included 100 symptomatic patients with PCR-confirmed CCHF admitted to the isolation ward of Al-Hussein Teaching Hospital between February 2022 and April 2023. Demographic characteristics, animal-contact history, bleeding manifestations, hematologic indices, coagulation parameters, alanine aminotransferase (ALT), C-reactive protein (CRP), renal function, hospital course, complications, and outcomes were abstracted from medical records.

Results: Among 100 patients, 55 were male and 45 were female; 75 patients recovered and 25 died, giving an in-hospital mortality of 25%. Thrombocytopenia was present in 94%, CRP was elevated in 76%, ALT in 64%, white blood cell counts were outside the reference range in 72%, D-dimer was elevated in 38%, activated partial thromboplastin time was prolonged in 37%, and acute kidney injury was documented in 15%. Mortality was significantly associated with abnormal white blood cell counts, prolonged coagulation parameters, elevated D-dimer, elevated ALT, elevated CRP, impaired renal function, animal-contact history, and bleeding-status category. All 25 deaths occurred among patients with recorded complications and intensive care unit admission. Platelet status and hemoglobin category were not significantly associated with outcome in the original analysis.

Conclusion: Hematologic dysregulation, coagulation abnormalities, systemic inflammation, and hepatic and renal dysfunction were associated with mortality in this cohort. Because the study was retrospective and the analyses were unadjusted, these findings should be interpreted as clinical risk signals rather than independent prognostic effects and should be validated in larger multicenter cohorts.