The Viral Load Rather Than the Duration of Viremia Is Associated With the Severity of Hemorrhagic Fever With Renal Syndrome

Hemorrhagic fever with renal syndrome (HFRS) is caused by Hantavirus infection, with a case fatality rate of 0.1%–1%. We longitudinally monitored HTNV RNA kinetics in 345 plasma samples from 137 HFRS patients, with serial viral load measurements every 3 days until the virus was cleared. Our analysis showed no correlation between viremia duration and disease severity. However, the viral load during the febrile phase was identified as an independent predictor of HFRS severity. Significant differences (p < 0.001) were observed between mild and severe cases in white blood cell (WBC), procalcitonin (PCT), C-reactive protein(CRP), platelet (PLT), urea nitrogen (BUN), and creatinine (Cr). These findings suggest that immune dysregulation triggered by the virus, rather than direct cytopathic effects might drive the tissue injury. Further investigation of virus-host immune interactions is critical for informing therapeutic strategies.