Objective  To investigate the clinical significance of severe fever with thrombocytopenia syndrome virus (SFTSV) load combined with platelet count (PLT) and thrombin time (TT) in predicting the prognosis of fever patients with thrombocytopenia syndrome (SFTS).

Methods  A total of 100 patients with SFTS were selected and divided into survival group (n=77) and death group (n=23) based on their prognosis. Clinical general information, symptoms, PLT, coagulation indexes, and SFTSV load were compared between the survival and death groups, and their impacts on prognosis of patients were analyzed.

Results  The duration of fever in the death group was longer than that in the survival group (P < 0.05). The proportion of patients with gastrointestinal bleeding, altered mental status, renal impairment, cardiac impairment, and disseminated intravascular coagulation (DIC) was higher in the death group than in the survival group (P < 0.05). PLT was lower in the death group than in the survival group, while TT and activated partial thromboplastin time (APTT) were longer in the death group(P < 0.05). The proportion of patients with logarithm of copy number for SFTSV load ≥5 was higher in the death group than in the survival group (P < 0.05). Logistic regression analysis showed that gastrointestinal bleeding, renal impairment, cardiac impairment, DIC, PLT, TT, and SFTSV load were factors influencing patients' mortality (P < 0.05). The area under the receiver operating characteristic (ROC) curve of the equation predicting patients'mortality was 0.919 (95%CI, 0.860 to 0.977), with sensitivity and specificity of 95.70% and 81.80%, respectively.

Conclusion  The prognosis of SFTS patients is influenced by factors such asgastrointestinal bleeding, renal impairment, cardiac impairment, DIC, PLT, TT, and virus load. The equation constructed based on these influencing factors has certain value in predicting patients' prognosis.