Publication:

Multiplex PCR assay findings of patients with clinically suspected acute viral encephalitis: an observational study in a tertiary care hospital

Background Acute viral encephalitis is a life-threatening neurological emergency characterized by fever, seizures, and altered consciousness. Rapid identification of viral pathogens is essential for timely management, yet conventional diagnostic tools often have limited sensitivity. This study aimed to determine the multiplex PCR assay findings and describe the clinical, MRI, and CSF characteristics of patients with clinically suspected acute viral encephalitis in a tertiary care hospital.

Methods This observational study was carried out at the Department of Neurology during December 2024 to November 2025 in Chittagong Medical College Hospital, Chattogram, Bangladesh of 100 patients irrespective of age and sex with clinically suspected acute viral encephalitis. Detailed clinical evaluation, routine laboratory tests, CSF biochemical and cytological analysis, and MRI imaging were performed. CSF samples were tested using a multiplex PCR panel for detection of common viral pathogens.

Results The mean age of patients was 45.28±19.95 years, with nearly equal male (51%) and female (49%) distribution. Fever (100%), altered consciousness (97%), and confusion (81%) were the predominant clinical features. MRI abnormalities were observed in 53% of patients, mainly FLAIR/T2 changes (51%), restricted diffusion (51%), and hypoxic changes (43%). CSF analysis revealed a predominantly lymphocytic profile (median lymphocytes 98%) with preserved CSF/blood glucose ratio (median 0.555). Multiplex PCR detected viral pathogens in 32% of cases. The majority (68%) of patients were mPCR-negative.

Conclusions Despite characteristic clinical, MRI, and CSF features, most cases remained mPCR-negative, highlighting the limitations of current diagnostic panels and the likelihood of undetected viral etiologies. Integrating broader molecular testing may improve diagnostic yield in resource-limited settings.