Description and validation of a novel real-time RT-PCR enterovirus assay.

BACKGROUND Enteroviruses are a leading cause of aseptic meningitis in adult and pediatric populations. We describe the development of a real-time RT-PCR assay that amplifies a small target in the 5' nontranslated region upstream of the classical Rotbart enterovirus amplicon. The assay includes an RNA internal control and incorporates modified nucleotide chemistry. METHODS We evaluated the performance characteristics of this design and performed blinded parallel testing on clinical samples, comparing the results with a commercially available RT-PCR assay (Pan-Enterovirus OligoDetect kit) that uses an enzyme immunoassay-like plate end detection. RESULTS We tested 778 samples and found 14 discrepant samples between the 2 assays. Of these, the real-time assay detected 6 samples that were negative by the OligoDetect kit, 5 of which were confirmed as positive by sequence analysis using an alternative primer set. Eight discrepant samples were positive by the OligoDetect kit and real-time negative, with 6 confirmed by sequencing. Overall, detection rates of 97% and 96% were obtained for the OligoDetect kit and real-time assays, respectively. Sequence analysis revealed the presence of a number of single nucleotide polymorphisms in the targeted region. The comparative sensitivities of the 2 assays were equivalent, with the limit of detection for the real-time assay determined to be approximately 430 copies per milliliter in cerebrospinal fluid. CONCLUSIONS This novel real-time enterovirus assay is a sensitive and suitable assay for routine clinical testing. The presence of single nucleotide polymorphisms can affect real-time PCR assays.