Comparison of a conventional polymerase chain reaction with real-time polymerase chain reaction for the detection of neurotropic viruses in cerebrospinal fluid samples.

PURPOSE To compare a conventional polymerase chain reaction (PCR) and real-time PCR for the detection of neurotropic DNA viruses. MATERIALS AND METHODS A total of 147 cerebrospinal fluid (CSF) samples was collected from patients attending a tertiary care hospital in South India for a period from 2005 to 2008. All these samples were tested using a conventional multiplex/uniplex PCR and a real-time multiplex/uniplex PCR. This technique was used to detect a large number of herpes viruses responsible for central nervous system infections, including HSV-1, HSV-2, VZV, CMV and EBV and the polyoma virus JCV. RESULTS Overall, in the entire set of samples, the real-time PCR yielded 88 (59.9%) positives and conventional PCR had six (4.1%) positives. CONCLUSION Our results suggest that the real-time PCR assay was more sensitive compared with the conventional PCR. The advantage of real-time PCR is that it can be performed much faster than conventional PCR. Real-time PCR is less time-consuming, less labour-intensive and also reduces the chance of contamination as there is no post-amplification procedure. In the entire study population, the major viruses detected using real-time PCR were EBV (34%), HSV-2 (10.8%) and VZV (6.8%).