[Prognostic Value of the CURB-65+B Score in Patients with Crimean Congo Hemorrhagic Fever and Its Comparison with...

Crimean-Congo hemorrhagic fever (CCHF) is a zoonotic viral hemorrhagic disease with a wide clinical spectrum ranging from mild clinical presentations to fatal outcomes. Reported case-fatality rates vary between 3% and 30%. Therefore, early identification of high-risk patients and referral to appropriate centers are of critical importance in reducing mortality. In this study, we aimed to evaluate the performance of the CURB-65+B score in predicting mortality in patients with CCHF and to compare it with the Acute Physiology and Chronic Health Evaluation II (APACHE II), Sequential Organ Failure Assessment (SOFA), Severity Grading System (SGS) and Severity Scoring Index (SSI) scoring systems. Data from 254 adult CCHF patients who were followed in a tertiary care center and whose diagnosis were confirmed by reverse transcription polymerase chain reaction and/or IgM positivity were retrospectively analyzed. Demographic, clinical and laboratory data were recorded and CURB-65, CURB-65+B, SOFA, APACHE II, SGS and SSI scores were calculated at admission. Survivors and non-survivors were compared; the predictive performance of each scoring system for mortality was assessed using receiver operating characteristic (ROC) analysis and multivariable logistic regression analysis was performed. The overall mortality rate was 2.8% (n= 7). Non-survivors were older and more frequently presented at admission with confusion, hypotension, tachycardia, tachypnea and bleeding. In laboratory analyses, platelet counts and fibrinogen levels were lower in non-survivors compared with survivors, whereas aspartate aminotransferase, alanine transaminase, lactate dehydrogenase, activated partial thromboplastin time, international normalized ratio, D-dimer and C-reactive protein (CRP) levels were higher. In ROC analysis, the most powerful laboratory predictors of mortality were CRP [>14.6 mg/L; area under curve (AUC)= 0.938], prothrombin time (>13.5 s; AUC= 0.996), creatinine (>1.2 mg/dL; AUC= 0.882), and D-dimer (>4770 µg/L; AUC= 0.662). The highest overall accuracy, however was obtained with the CURB-65+B score (AUC= 0.997; 100% sensitivity; 98.8% specificity; p< 0.001). In multivariable analysis, only the CURB-65+B score was identified as an independent predictor of mortality (Odds ratio≈ 14; 95% confidence interval= 2.7-72.6; p= 0.002). Moreover, mortality was markedly higher in patients with a CURB-65+B score ≥3, whereas no deaths were observed among patients with a score <3. With its simple and easily applicable structure, the CURB-65+B score represents a powerful tool for predicting mortality in CCHF. It may facilitate the rapid identification of high-risk patients, recognition of those requiring intensive care and timely referral to appropriate centers in emergency departments and endemic settings. Compared with existing mortality scoring systems, CURB-65+B appears to be more practical, distinctive and to possess a higher predictive accuracy and thus may fill an important gap in the clinical management of CCHF.