Clinical characteristics and risk factors for mortality of patients with severe fever with thrombocytopenia syndrome

Abstract

Objective To summarize the clinical and laboratory characteristics of patients with severe fever with thrombocytopenia syndrome (SFTS) and to identify the related risk factors for mortality. Methods Clinical features and laboratory parameters were collected from 40 SFTS patients (7 deaths and 33 survivors). Dynamic changes of laboratory data were compared between the two groups, including white blood cell count (WBC), platelet count (PLT), alanine aminotransferase (ALT), aspartate aminotransferase (AST), creatine kinase (CK), lactate dehydrogenase (LDH), prothrombin time (PT), activated partial thromboplastin time (APTT) and thrombin time (TT). Continuous variables with normal distribution were compared with t test, and those with non-normal distribution were compared with nonparametric test; categorical variables were compared with χ2 test. Univariate Logistic regression was used to evaluate the risk factors associated with death. Results For the deceased patients and the survivors, the APTT were 56.40 s and 44.45 s, respectively (Z=5.419, P=0.04) at day 1—7. Those were 66.25 s and 36.85 s, respectively (Z=10.112, P=0.009) at day 8—10, and (125.06±11.88) s and (33.44±6.50) s, respectively (t=45.760, P 15 s (OR=24.00, 95%CI: 1.99—289.60), APTT>70 s (OR=42.67, 95%CI: 3.54—514.85) and TT>120 s (OR=0.14, 95%CI: 0.02—0.88) were risk factors for the death of SFTS patients (all P<0.05). Conclusion Prolonged APTT, TT and PT at early stage and progressively increasing during the disease course suggest poor prognosis of SFTS. Key words: Severe fever with thrombocytopenia syndrome bunyavirus; Orthobunyavirus; Death; Risk factors