Key predictors of mortality in Crimean-Congo haemorrhagic fever: a retrospective multicentre cohort study

Objective This study aimed to identify key predictors of mortality in patients with Crimean-Congo haemorrhagic fever (CCHF). Our specific goals included characterizing the demographic and clinical features of hospitalized CCHF patients in Türkiye, determining the factors associated with mortality among these patients, and evaluating the impact of early ribavirin administration. Methods A retrospective study was conducted on 1103 CCHF patients across 18 hospitals in Türkiye from 1 January 2019 to 20 November 2024. All data were obtained via an online data collection system by the designated physician at each centre. Patients with laboratory-confirmed CCHF infection who were hospitalized were included in the study. Univariate analyses and time-dependent Cox regression were conducted. Results Of the 1103 patients, 65.7% (725/1102) were men; 87.2% (962/1103) resided in rural areas; and the mean age was 53 years. Ticks were identified as the transmission route in 68.4% (755/1103) of the cases. Comorbidities included diabetes mellitus, chronic heart disease, and hypertension; 4.6% (51/1103) of the patients developed healthcare-related infections. Intensive care unit admission was required in 8.0% (88/1103) of the patients, and the overall mortality rate was 5.1% (56/1103). In univariate analyses, age ≥50 years (odds ratio [OR], 3.1; 95% CI, 1.58–6.08; p < 0.001) and diabetes mellitus (OR, 4.49; 95% CI, 2.20–9.18; p < 0.001) were associated with increased mortality. Both variables remained statistically significant predictors in the multivariate analysis. Although early ribavirin administration, ≤96 hours from symptom onset, did not reach statistical significance in univariate analysis (OR, 0.52; 95% CI, 0.26–1.05; p = 0.065), it was significantly associated with reduced mortality in time-dependent Cox regression (adjusted hazard ratios, 0.21; 95% CI, 0.07–0.69; p = 0.010). Discussion Key factors such as age and comorbidities can predict mortality in CCHF patients. Timely identification of these predictors, along with early administration of ribavirin, may contribute to improved survival and better clinical outcomes. © 2025 European Society of Clinical Microbiology and Infectious Diseases.