Rare case of intracranial hemorrhage associated with seoul virus infection diagnosed by metagenomic next‐generation sequencing

BACKGROUND: Seoul virus (SEOV) is a Hantavirus and the causative pathogen of Hemorrhagic Fever with Renal Syndrome (HFRS). Diagnosing SEOV infection is difficult because the clinical presentations are often undistinguishable from other viral or bacterial infections. In addition, diagnostic tools including serological and molecular assays are not readily available in the clinical settings. CASE REPORT: A 57‐year‐old male presented with fever and a sudden loss of consciousness in November 2019. Computed tomography (CT) scan showed subdural hematoma, subfalcine herniation, and brain infarction. He developed thrombocytopenia and elevated transaminases, but no rashes or obvious kidney damage. He reported having a rat bite. HFRS was suspected. The Hantavirus IgG was positive, and the metagenomic next‐generation sequencing (mNGS) detected SEOV sequences directly in the blood. CONCLUSION: This report highlights the importance of suspecting SEOV infection in febrile patients with thrombocytopenia and elevated liver enzymes despite the absence of hemorrhagic manifestations of skin and renal syndromes. Next‐generation sequencing is a powerful tool for pathogen detection. Intracranial hemorrhage and brain infarction as extrarenal manifestations of HFRS are rare but possible as demonstrated in this case.