Metagenomic NGS Outperforms Standard PCR for Atypical HSV-2 Encephalitis Diagnosis
A retrospective analysis of seven patients with HSV-2 encephalitis demonstrated the diagnostic value of metagenomic next-generation sequencing when conventional CSF PCR may miss atypical presentations. Higher viral sequence counts correlated with worse outcomes, and early diagnosis within three days was associated with full recovery. The study adds to limited clinical data on adult HSV-2 encephalitis in immunocompetent individuals.
The original study
Analysis of the Clinical Features of HSV-2 Encephalitis Confirmed by the mNGS Technique: Insights Derived from Seven Patient Studies.
- Authors
- Xie S, Zhang H, Xie Y, Liu F, Ye S, Liu X, et al.
- Journal
- Infection and drug resistance
- PMID
- 41877907
Original abstract
BACKGROUND: Herpes simplex virus type 2 (HSV-2) encephalitis is rare in immunocompetent adults. Diagnosis typically depends on cerebrospinal fluid (CSF) polymerase chain reaction (PCR), which has limited sensitivity and potential for false negatives. Metagenomic next-generation sequencing (mNGS) provides unbiased pathogen detection, facilitating rapid HSV-2 identification in CSF and minimizing misdiagnosis risks, especially in atypical cases or immunocompetent individuals. This study examines the diagnostic value of mNGS in a cohort of patients with HSV-2 encephalitis presenting atypically. METHODS: A retrospective analysis was performed on patients diagnosed with HSV-2 encephalitis using mNGS at our institution between January 2022 and January 2025. Clinical characteristics, ancillary test results, and patient outcomes were analyzed to evaluate the diagnostic value of mNGS. RESULTS: Seven patients (2 males, 28.57%; 5 females, 71.43%) with a mean age of 33.57 years were included; one had pre-existing immunodeficiency (14.28%). Most presented atypical symptoms; six treated within three days fully recovered, while one with delayed treatment died. Mean follow-up was 14.71 ± 5.82 months. Higher viral sequence counts correlated with worse outcomes. Initial CSF analysis showed normal cell counts in one patient; all exhibited lymphocytic pleocytosis and elevated protein levels. CONCLUSION: This study contributes to the limited clinical data on adult HSV-2 encephalitis by summarizing clinical manifestations and treatment outcomes, thereby informing improved diagnostic and management strategies. It also highlights the prognostic importance of early diagnosis and immune status assessment through the application of mNGS.