Usefulness of real-time reverse transcription-polymerase chain reaction for the diagnosis of echovirus aseptic meningitis using cerebrospinal fluid.

Quantitative real-time reverse transcription-polymerase chain reaction (q-RT-PCR) was used to diagnose echovirus infection and the results were compared to those obtained with the viral culture rate. Cerebrospinal fluid (CSF) from a total of 40 aseptic meningitis patients was used. Positive CSF samples, determined by viral culture (n=29), contained significantly higher echovirus genome copy numbers (mean, 329 copies/microL) than did culture-negative CSF samples (n=11) (mean, 34.2 copies/microL; P<0.05). Echoviruses were identified as echovirus serotype 9 (E-9) (n=21); E-30 (n=16); and E-5, E-7, and E-18 (n=1 each) by neutralization and/or conventional PCR-sequencing techniques. Viral culture-positive samples were collected at 1.41-/+1.27 days after the onset of illness, and culture-negative samples were collected at 4.91-/+3.34 days. Samples from which virus could be isolated were collected significantly earlier than were samples from which virus could not be isolated. These results strongly suggest the importance of early collection of CSF for echovirus isolation, and demonstrate the high sensitivity of q-RT-PCR for the detection of echoviruses in CSF.