Identification of Adenovirus, Influenza Virus, Parainfluenza Virus, and Respiratory Syncytial Virus by Two Kinds of Multiplex Polymerase Chain Reaction (PCR) and a Shell Vial Culture in Pediatric Patients with Viral Pneumonia

Lee, Jong-Han; Chun, Jin-Kyong; Kim, Dong Soo; Park, Yongjung; Choi, Jong Rak; Kim, Hyon-Suk

We focused on the four major respiratory viruses of AdV, IFV, PIFV, and RSV. The exact concordance rate between the two kinds of multiplex PCR and R-Mix viral culture was 48.5% (50/103). Our results of the two multiplex PCR showed an equivalent or higher positive rate than in other studies. 9, 10, 14 Two kinds of multiplex PCR reagents showed different positivity according to the virus type. The positive rate of the Seeplex TM RV detection kit was higher than the Labopass TM RV kit for IFV and RhV. However, the Identification of Pediatric Respiratory Virus Labopass TM RV kit detected more HMPV than the Seeplex TM RV kit. Discrepant results between these two types of multiplex PCR and R-Mix culture comprised 51.5% (53/103) of the total. Weinberg, et al. 17 reported that the PCR method could detect viruses two times more, compared with virus culture. Our study showed that the concordance rate of Seeplex PCR to the virus culture was 83% (90/103), and that of Labopass PCR, 80.6% (83/103). These results were similar to previous reports, of 83.2% (556/668) 17 and 80% (40/50). 20 The discrepancy might be caused from multiplex PCR limitations. One of the major limitations of PCR detection is false-negative results as a consequence of PCR inhibitors present in clinical samples that are not removed by the extraction process. 9 Another limitation is the principle of PCRs, which could produce false results if a primer region has nucleotide variation and is unable to detect new types or strains of a virus. This is the reason that direct antigen tests or virus cultures cannot be completely substituted by solitary multiplex PCR tests until now. 21 We noticed a 6.8% (15/220) coinfection rate (more than 2 virus types identified) by the Seeplex TM RV kit and 5.9% (13/220) by the Labopass TM RV kit. Previous studies have suggested that double-virus infections are associated with greater severity of respiratory tract infection. 22 In our study, we could not find out any remarkable parameters or difference of clinical severity in cases of coinfection.