A children patient with intracranial infection after brain surgery associated with elevated Torque Teno Virus.

Introduction: Intracranial infections are challenging to diagnose, especially in immunocompromised patients. Next-generation sequencing (NGS) has emerged as a powerful tool for broad pathogen detection, including Torque Teno Virus (TTV). Elevated TTV loads have been associated with immune dysfunction, potentially serving as a biomarker for opportunistic infections. However, the clinical significance of TTV in intracranial infections remains unclear. Case presentation: An 8-year-old boy developed a complex intracranial infection following craniotomy, characterized by elevated TTV levels in cerebrospinal fluid (CSF) and subsequent fungal co-infection. Initial empirical antibiotics failed to fully control the infection. NGS identified TTV in the CSF, prompting the addition of intravenous immunoglobulin. Recurrent infection led to the suspicion of a fungal infection, confirmed by positive G/GM tests and successful treatment with fluconazole. Conclusion: Elevated TTV levels in CSF may indicate underlying immunodeficiency and predispose patients to opportunistic fungal infections. Prompt fungal testing including qPCR is recommended when TTV is detected in CSF. Further research is needed to elucidate the role of TTV in clinical infections and optimize management strategies.