Objective:

To explore the challenges in diagnosing meningitis/encephalitis (M/E) and the potential of metagenomic next-generation sequencing (mNGS) to improve diagnostic outcomes, addressing the significant diagnostic gap.

Key Findings:

• Over 60% of M/E cases remain undiagnosed despite extensive testing, highlighting the need for improved diagnostic methods.
• Earlier use of mNGS could reduce microbiologic testing by over 60% in infectious cases and by more than 90% in autoimmune encephalitis, demonstrating its efficiency.
• Time to diagnosis could be shortened by approximately 7 days for infectious cases and 10 days for autoimmune encephalitis, significantly impacting patient management.

Interpretation:

mNGS can significantly streamline the diagnostic process for M/E, particularly in complex cases, by providing rapid and comprehensive pathogen detection, which is crucial for timely treatment.

Limitations:

• mNGS does not replace initial diagnostic tests and requires careful interpretation, particularly regarding false positives.
• Contamination control is crucial due to the assay's high sensitivity, necessitating strict laboratory protocols.

Conclusion:

Integrating mNGS earlier in the diagnostic pathway for M/E may enhance patient management, reduce unnecessary testing, and improve antimicrobial stewardship, ultimately leading to better patient outcomes.