Severity scoring index for Crimean-Congo hemorrhagic fever and the impact of ribavirin and corticosteroids on fatality

Abstract

Background: Patients infected with Crimean-Congo hemorrhagic fever (CCHF) virus present with a wide clinical spectrum. In observational studies, the effects of therapeutic agents are confounded by severity. We describe use of a clinical severity scoring index (SSI) for CCHF patients and assess the effect of ribavirin and corticosteroid therapy on the case-fatality rate, stratified by SSI.

Methods: The study group included hospitalized patients who received a diagnosis of CCHF at the Infectious Diseases and Clinical Microbiology Clinic of Ankara Numune Education and Research Hospital between 2004 and 2011. The SSI included platelet count, bleeding, fibrinogen level, activated partial thromboplastin time, and somnolence. The effects of ribavirin and corticosteroid on the case-fatality rate were studied by univariate and multivariate analysis, stratified by SSI.

Results: Two hundred eighty-one confirmed cases of CCHF were included in the study. Of 281 patients, 23 (8%) died. The mean age (±SD) of the patients was 47 ± 16 years. Forty-nine percent were female. The mean duration of stay at our clinic after onset of symptoms was 4.4 days, with a range of 1-14 days. In multivariate analysis of factors for the prediction of death, the SSI (odds ratio [OR], 3.27; 95% confidence interval [CI], 2.09-5.13) and ribavirin use (OR, 0.04; 95% CI, .004-.48) were found to be statistically significant factors.

Conclusion: The SSI is an accurate predictor of death and will therefore be a useful tool for case management and for drug-assessment studies. After stratification of cases by SSI, ribavirin was found to be effective in reducing the case-fatality rate, especially among moderately ill patients, whereas steroids were found to be beneficial particularly among patients with severe disease.

Keywords: Crimean-Congo hemorrhagic fever; corticosteroids; ribavirin; severity scoring index.