Differential Diagnosis in Crimean-Congo Hemorrhagic Fever: A Comprehensive Analysis in an Endemic Region During the COVID-19 Pandemic

Introduction: Crimean-Congo hemorrhagic fever (CCHF) is a tick-borne zoonotic viral infection, causing non-specific symptoms like headache, fever, sore throat, myalgia, and arthralgia. Due to its overlapping signs with various diseases, differential diagnosis becomes crucial, especially in the endemic regions. This study aimed to compare patients tested with a pre-diagnosis of CCHF.
Methods: Adult patients who presented with nonspecific symptoms such as headache, fever, and bleeding, were tested for CCHF between April 2019 and December 2022 were included. CCHF diagnosis is based on detecting RNA via real-time polymerase chain reaction or immunoglobulin M using enzyme-linked immunosorbent assay. Patients were categorized into three groups: Group 1 (Non-infectious disease), Group 2 (Infectious/Non-CCHF disease), and Group 3 (CCHF). Diagnoses and clinical features were determined for Groups 1 and 2. Laboratory parameters of all three groups were compared.
Results: Among 259 patients, 152 were diagnosed with CCHF, and 107 with non-CCHF conditions. coronavirus disease 2019 (COVID-19) was the most prevalent infectious disease, while toxic hepatitis led non-infectious cases. CCHF patients displayed distinctive laboratory values, with lower white blood cell count, lymphocyte count, platelet count, creatinine, fibrinogen, and higher Aspartate Aminotransferase, Alanine Aminotransferase, and Lactate dehydrogenase compared to other groups.
Discussion and Conclusion: The differential diagnosis of CCHF is crucial in endemic countries, with COVID-19 emerging as a significant associated disease. CCHF is discerned from infectious diseases by lower blood count parameters and higher liver function tests.

Keywords: COVID-19; Crimean-Congo hemorrhagic fever; Differential diagnosis; Infectious diseases