The prevalence and influence of EBV infection in patients with severe fever with thrombocytopenia syndrome.

OBJECTIVE

Severe fever with thrombocytopenia (SFTS) is a fatal emerging infectious disease. Co-infection, mainly with bacterial and fungal infections, in association with poorer outcomes in SFTS, but few studies have examined on viral infections. We aimed to investigate the prevalence of Epstein‒Barr virus (EBV) infection and its effects on the clinical features and mortality in patients with SFTS.

METHODS

We retrospectively reviewed 104 patients with confirmed SFTS between 2011 and 2025, and analyzed their laboratory test results and clinical data.

RESULTS

Of 104 SFTS patients, 48.10% had EBV infection. Compared to those without EBV infection, these patients were more likely to have bacterial infection in blood (p = 0.027), lower white blood cell (p < 0.001) and neutrophil counts (p = 0.019), lower serum calcium (p = 0.043), and higher alanine aminotransferase (p = 0.013), adenosine deaminase (p = 0.018), and urinary protein (p = 0.005). Mortality rates were higher in EBV-infected patients (7 [14%] vs. 4 [7.4%], p = 0.275), though not statistically significant. In this study, decreased WBC count and elevated ALT level were independently associated with EBV infection in SFTS patients (OR = 0.391 [95% CI, 0.233-0.657] and 1.006 [95% CI, 1.001-1.011], both p < 0.05).

CONCLUSIONS

SFTS patients are at high risk for EBV infection. Those with EBV infection exhibit more severe clinical manifestations, although short-term survival does not differ significantly. Decreased WBC count and elevated ALT are risk factors for EBV infection in SFTS patients. The need for targeted treatment of EBV infection remains uncertain.