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

Crimean-Congo Hemorrhagic Fever (CCHF) is a viral hemorrhagic fever common in many regions of the world. There are many diseases in the differential diagnosis of CCHF. In our study, we aimed to predict the diagnosis of CCHF at the time of initial presentation by using clinical and laboratory findings in patients with a preliminary diagnosis of CCHF. In our study, 74 patients with a definitive diagnosis of CCHF and 43 patients with a preliminary diagnosis of CCHF but not diagnosed with CCHF were compared in terms of demographic, clinical and laboratory findings. Multivariate logistic regression analysis and Receiver Operating Characteristics (ROC) curve were used to determine variables to predict the diagnosis of CCHF. Living in an endemic area, tick bite, fever, CRP below 48 mg/L and PCT below 0.52 ng/mL were determined as independent risk factors for CCHF diagnosis. The specificity for cut off values of 2485 mm³ for WBC and 970 mm³ for neutrophil count were 86 % and 93 %, respectively. The sensitivity for cut off values of 48 mg/L for CRP and 0.52 ng/mL for PCT were 90.5 % and 82.4 %, respectively. In-hospital and 28-day mortality were higher in the non-CCHF group. The differential diagnosis of CCHF is important for planning appropriate isolation procedures and treatments for patients. Additionally, by excluding CCHF, it allows for the early consideration of other diseases in the non-CCHF group that show high mortality. In patients living in endemic areas with tick bites and clinical findings compatible with CCHF, easily accessible tests such as WBC, neutrophil count, CRP and PCT, within the cut-off values identified in our study, will assist in diagnosing CCHF at the initial presentation.