Analysis of clinical features and early warning indicators of death from severe fever with thrombocytopenia syndrome

Abstract

Objective: To determine the clinical features of confirmed cases of severe fever with thrombocytopenia syndrome (SFTS) and to explore the early warning indicators of death from SFTS.

Methods: A retrospective case-control study was performed at a single medical institution in Yantai. A total of 20 SFTS patients who died (death group) during January 2014 to December 2015 and another 40 age- and sex-matched SFTS patients who survived (survivor group) were identified from the case records. The differences in demographic characteristics, clinical signs and symptoms, and laboratory parameters in the early stage of disease were compared between the two groups. Conditional logistic regression was used to identify the independent risk factors for mortality in SFTS patients.

Results: Univariate logistic regression analysis showed that a disturbance of consciousness, pulse-temperature deficit, neurological signs, hemorrhagic manifestations, pulmonary infection, decreased lymphocyte percentage, high lactate dehydrogenase and creatine kinase levels, increased serum creatinine, blood urea nitrogen, and C-reactive protein (CRP), hyponatremia, and prolonged activated partial thromboplastin time (APPT) and prothrombin time were associated with mortality. On multivariate logistic regression analysis, the independent predictors of death were neurological signs (odds ratio (OR) 31.247, 95% confidence interval (CI) 4.813-202.853), hemorrhagic manifestations (OR 20.251, 95% CI 2.056-199.443), disturbance of consciousness (OR 15.359, 95% CI 2.139-110.268), hyponatremia (OR 5.280, 95% CI 1.235-22.575), increased CRP (OR 2.641, 95% CI 1.090-6.396), increased serum creatinine (OR 6.776, 95% CI 1.047-43.840), and prolonged APTT (OR 6.018, 95% CI 1.450-24.975).

Conclusions: Neurological signs, hemorrhagic manifestations, disturbance of consciousness, hyponatremia, prolonged APTT, and increased CRP and serum creatinine are risk factors for death in SFTS.

Keywords: Death; Orthobunyavirus; Prediction; Severe fever with thrombocytopenia syndrome.