Fatal patients with severe fever with thrombocytopenia syndrome in China

Severe fever with thrombocytopenia syndrome (SFTS) is an emerging tick-borne infectious disease with a high case fatality rate. Key gaps remained as to the assessment of the clinical picture in fatal cases.

A retrospective study was performed on 496 patients with fatal SFTS. The dynamic pattern of clinical manifestations and laboratory indicators were delineated.

The mean age of the fatal cases was 69.0 years (standard deviation: 9.3), and 52.8% were male. The median clinical course from disease onset to death was 11 (interquartile range: 10-13) days. A total of 11 laboratory indicators (neutrophil %, platelet, aspartate aminotransferase, aspartate aminotransferase/alanine transaminase, lactate dehydrogenase, creatine kinase, cystatin C, D-dimer, activated partial thromboplastin time, thrombin time, glucose) persistently deviated from normality across hospitalization. The critical time points when the rapid worsening of the indicators was at 6-9 days after disease onset. Alanine transaminase, AST, lactate dehydrogenase, total bile acid, gamma-glutamyl transpeptidase, and glucose were all elevated to a more pronounced level in fatal cases of those aged ≤70 years.

The fatal outcome was developed in rather a short course after the disease onset of SFTS. High vigilance should be put on the key time points when the severe worsening and severe complications occur.