Simultaneous detection of parainfluenza viruses 1 and 3 by real-time reverse transcription-polymerase chain reaction.

Human parainfluenza virus (HPIV) types 1 and 3 are major viral pathogens responsible for upper and lower respiratory tract infections. The diagnosis of these two species is achieved generally by specific reverse transcription-polymerase chain (RT-PCR) reaction methods. In this study, a real-time RT-PCR was developed using a common pair of primers–probe (HPIV-1+3) for the simultaneous detection of both HPIV-1 and HPIV-3 genomes. Results obtained in a 10-fold dilution series assay demonstrate a high sensitivity of the assay with a lowest detection limit of approximately one plasmid copy for both HPIV-1 and HPIV-3. A comparison of HPIV-1 and HPIV-3 clinical sample detection between specific HPIV-1/HPIV-3 pairs of primers–probes and the HPIV-1+3 combination clearly shows that the latter is significantly more sensitive (gain of about five threshold cycles) than the former for HPIV-3 detection, while equivalent values are observed for HPIV-1. The HPIV-1+3 combination constitutes a more rapid, more sensitive, and less expensive alternative than classical or multiplex real-time RT-PCR assays usually used in clinical laboratories.