Crimean-Congo hemorrhagic fever: Strategies for diagnosis at initial admission

Area of Science:

• Infectious Diseases
• Epidemiology
• Clinical Diagnostics

Background:

• Crimean-Congo Hemorrhagic Fever (CCHF) is a significant viral hemorrhagic fever with a broad differential diagnosis.
• Accurate and timely diagnosis of CCHF is essential for appropriate patient management, including isolation and treatment protocols.

Purpose of the Study:

• To develop a predictive model for CCHF diagnosis using clinical and laboratory findings at the time of initial patient presentation.
• To identify independent risk factors and establish diagnostic cut-off values for CCHF.

Main Methods:

• A comparative study involving 74 patients with confirmed CCHF and 43 patients with a preliminary CCHF diagnosis but ultimately negative.
• Multivariate logistic regression and Receiver Operating Characteristics (ROC) curve analysis were employed to identify predictive variables.
• Demographic, clinical, and laboratory data were analyzed.

Main Results:

• Independent risk factors for CCHF diagnosis included residing in an endemic area, history of tick bite, fever, C-reactive protein (CRP) < 48 mg/L, and procalcitonin (PCT) < 0.52 ng/mL.
• Specific cut-off values demonstrated high diagnostic accuracy: WBC 2485 mm³ (86% specificity), Neutrophil count 970 mm³ (93% specificity), CRP 48 mg/L (90.5% sensitivity), PCT 0.52 ng/mL (82.4% sensitivity).
• Higher in-hospital and 28-day mortality rates were observed in the non-CCHF group.

Conclusions:

• The study successfully identified key indicators for the early diagnosis of CCHF.
• Utilizing easily accessible laboratory tests (WBC, neutrophil count, CRP, PCT) with established cut-off values can significantly aid in diagnosing CCHF upon initial presentation in endemic areas.
• Accurate CCHF diagnosis facilitates prompt treatment and isolation, while also enabling earlier consideration of alternative diagnoses in non-CCHF patients, potentially improving outcomes for high-mortality conditions.