Clinical Management Strategies for Severe Fever with Thrombocytopenia Syndrome Induced by Tick Bites: A Case Report and Literature Review.

BACKGROUND Severe fever with thrombocytopenia syndrome (SFTS) has a high mortality rate, and diagnosis and treatment options for SFTS-associated encephalopathy/encephalitis(SFTSAE) are limited. CASE REPORT A 79-year-old male farmer developed progressive dyspnea and productive cough 72 hours after tick exposure, accompanied by persistent high-grade fever (38.9°C). Following failed empirical antimicrobial interventions, he was transferred to our institution. At the same time, the local disease control center diagnosed him with fever with thrombocytopenia syndrome (SFTS). Initial evaluations at peripheral hospitals revealed thrombocytopenia (platelet 25×109/L) and leukopenia (WBC 1.24×10⁹/L). Despite aggressive therapy, including intravenous immunoglobulin (IVIG), favipiravir, doxycycline, meropenem, and platelet transfusions, progressive multiorgan failure manifested as metabolic acidosis (pH 7.24, lactate 6.57 mmol/L), hepatorenal and kidney dysfunction (ALT 665.2 U/L, AST 7764 U/L, creatinine 191 umol/L), hypoxemic respiratory failure (PaO₂/FiO₂ 160), and neurological decline (GCS 10). Despite 72 hours of aggressive critical care interventions, the patient died due to refractory multiorgan failure secondary to viral sepsis. CONCLUSIONS This case is a stark reminder of the rapid progression and severe nature of fever with thrombocytopenia syndrome associated with tick bites, emphasizing the critical need for individualized treatment strategies tailored to the clinical classification of the illness, particularly in severe cases that might involve neurological complications.