Evaluation of real-time RT-PCR compared with conventional RT-PCR for detecting human metapneumovirus RNA from...

Human metapneumovirus (hMPV) is an etiologic agent of respiratory tract infections. In this study, we compared the sensitivity and specificity of real-time reverse transcription (RT)-polymerase chain reaction (PCR), conventional RT-PCR, and nested PCR in detecting hMPV genes. A total of 146 clinical specimens from 143 patients who showed acute respiratory tract infection symptoms were tested by real-time RT-PCR, conventional RT-PCR, and nested PCR targeting for the fusion gene. We detected hMPV RNA from 14 (9.6%) clinical specimens (real-time RT-PCR, 8; conventional RT-PCR, 5; and nested PCR, 13). When conventional RT-PCR was the reference standard, the sensitivity and specificity of real-time RT-PCR were 100 and 97.9%, respectively. When nested PCR was the standard, the sensitivity and specificity of real-time RT-PCR were 53.8 and 99.2%, respectively. Therefore, real-time RT-PCR was more sensitive than conventional RT-PCR but less so than nested PCR. Phylogenetic analysis showed that the real-time RT-PCR detected four genetic sublineages of hMPV. These results taken together indicate that real-time RT-PCR is an efficient method for detecting four genetic sublineages of hMPV from clinical specimens.