Diagnosis, management, and prevention of Crimean-Congo haemorrhagic fever: a Delphi-based consensus study in Türkiye.

Background: Crimean-Congo haemorrhagic fever (CCHF) is a widely distributed viral haemorrhagic fever with expanding geographic range. As new regions encounter the disease, clinicians must make high-stakes decisions despite limited standardised management frameworks. Methods: In this multicentre, modified Delphi study, infectious diseases specialists were recruited from 19 centres in Türkiye via an open call through the professional communication channels of the Turkish Society of Clinical Microbiology and Infectious Diseases (known as KLİMİK). Eligibility was determined based on self-reported clinical experience. Eligible participants reported managing more than ten patients with CCHF as primary physicians, with no additional demographic or professional exclusion criteria applied. The Delphi process included three sequential rounds of anonymous online surveys (between Sept 26 2025, and Jan 1, 2026) and an interim structured clarification meeting (Nov 28-29, 2025), to map areas of agreement and heterogeneity across diagnosis, monitoring, therapeutics, and exposure management. Statements were analysed using Likert-scale methodology. Responses were summarised using medians, interquartile ranges, and proportions of agreement. Consensus levels were defined a priori. Findings: Of 45 ID specialists invited to participate in Round 1, 35 completed the questionnaire and were included in the analysis (78% response rate). All 35 eligible participants were invited to Round 2, and 32 (91%) completed the questionnaire. All 32 participants completed Round 3, with no attrition between Rounds 2 and 3. All participants reported experience of managing more than ten patients with CCHF; ∼85% of participants reported managing at least 50 confirmed cases. In total, 146 candidate statements were evaluated, of which 72 achieved early consensus in Round 1. Following iterative refinement, 39 of 56 statements (69.6%) met predefined consensus criteria in the final round, including eight with very high agreement and 22 with high agreement. Strong convergence was observed for early molecular testing and risk-based hospitalisation, ribavirin initiation within 4 days of symptom onset in confirmed cases, risk-adapted transfusion strategies guided by bleeding severity, and post-exposure prophylaxis after high-risk occupational exposure. Persistent heterogeneity remained regarding ribavirin initiation beyond the early symptomatic window, immunomodulatory therapies, and transfusion de-escalation strategies in selected scenarios. Interpretation: These findings should not be interpreted as formal guidelines. By transparently quantifying expert agreement and non-consensus, this study synthesises specialist clinical experience from a high incidence country and delineates areas of convergence and ongoing uncertainty relevant to both endemic and newly affected regions. Prospective studies are needed to validate key therapeutic and management strategies identified in this work. Funding: None.