Determination of Etiology and Epidemiology of Viral Central Nervous System Infections by Quantitative Real-Time Polymerase Chain Reaction in Central India Population.

INTRODUCTION: Viral infections of the central nervous system (CNS) are the most common cause of hospital admission in worldwide and remain a challenging disease for diagnosis and treatment. The most common infectious agents associated with viral CNS infections are cytomegalovirus (CMV), Epstein-Barr virus (EBV), varicella zoster virus (VZV), Japanese encephalitis virus (JEV), Dengue virus (DENV),West Nile virus(WNV), and Chandipura virus(CHPV). The aim of the present work was to find the etiology of CNS viral infection in the Central India population by transcriptase PCR (RT-PCR) comparing real-time polymerase chain reaction (PCR) method [one-step and two-step reverse transcriptase (RT-PCR)] in cerebrospinal fluid (CSF) and blood samples of CNS viral infections patients.

MATERIALS AND METHODS: One-step and two-step real-time PCR assays were evaluated in CSF and parallel blood samples from patients with viral CNS infections for detection of DNA and RNA viruses. A comparative analysis was also done between gDNA, gRNA, cDNA, and plasmid-based real-time PCR methods for an efficient quantitation of viral particles in clinical samples for determination of viral etiology.

RESULT: On evaluation of 150 CSF and 50 parallel blood samples from suspected cases of viral CNS infections, a viral etiology was confirmed in 21 (14%) cases, including 3% for EBV, 1% of CMV, and 5% for VZV and JEV. The one-step RT-PCR has a higher detection limit for detection and quantitation of viral RNA in comparison to two-step RT-PCR.

CONCLUSION: Our result reveals that VZV and JEV are the most usual cases of CNS viral infection in hospitalized patients in the Central India population and one-step RT-PCR shows higher viral load detection limits for quantitation of viral genome and more sensitivity in comparison to two-step RT-PCR.