Human pegivirus detected in patient with reversible severe encephalitis and axillary lymphadenopathy: a case report

Human pegivirus (HPgV) has been postulated as a potential etiological factor in encephalomyelitis and exhibits lymphotropic characteristics. However, the co-occurrence of encephalitis and lymphadenopathy with HPgV detected has never been reported. Herein, we report a case of a 48-year-old woman admitted with fever followed by sudden loss of consciousness. Radiological imaging demonstrated encephalitis and lymphadenopathy. Initial analysis of blood and cerebrospinal fluid (CSF) failed to reveal specific etiology. The only pathogen found in CSF was later determined to be HPgV using metagenomic next-generation sequencing (mNGS). After receiving treatment with acyclovir, meropenem, and ceftriaxone sodium, the patient fully recovered. This case contributes additional evidence in support of the hypothesis regarding the pathogenic potential of HPgV and highlights the diagnostic utility of mNGS in detecting rare pathogens.