Comparison of multiplex reverse transcription-PCR-enzyme hybridization assay with immunofluorescence techniques for the detection of four viral respiratory pathogens in pediatric community acquired pneumonia
The burden of illness due to viral respiratory pathogens in the pediatric population is increasingly being recognized. Children are considered among the groups at highest risk for viral pneumonia-associated morbidity and mortality. Clinical discrimination between different causative agents is extremely difficult. The main problems have been the lack of ‘gold standard’ method for obtaining viral etiology (Liolios et al., 2001). We believe that the identification of these viruses as causes of respiratory disease in these patients is the first step in determining how frequently they may cause serious problems and, hence, how hard we should push with accepted treatments. In this study, our aim was to compare between two modalities for diagnosis of viral illness among children with community-acquired pneumonia (CAP). Multiplex reverse transcription-PCR-enzyme hybridization assay and immunofluorescence antigen detection techniques for the detection of four viral respiratory pathogens (Influenza viruses A & B and Respiratory Syncitial Viruses A & B) were targeted to evaluate their diagnostic yield for these patients in our study. Among 56 respiratory samples were evaluated from children with clinical and radiological criteria of CAP; twenty-one patients had viral pneumonia proved by multiplex RT-PCR and/or IF technique with disease prevalence 35% (95% CI: 23:49). All 21 specimens were positive by multiplex RT-PCR, while 20 out of them were positive by IF. All results showed no discordance of detected viral pathogen. Initial comparison of IF results to those of RT-PCR generated a sensitivity 100% (95% CI: 83:100), a specificity 97.2% (95% CI: 85:99.9), a positive predictive value 95% (95% CI: 23:49.6), and a negative predictive value of 100% (95% CI: 74:99).
Conclusion: Multiplex reverse transcription PCR has an excellent potentials for diagnosis of viral pneumonia with a cost effective advantage in assessing simultaneously multiple clinically significant viruses. Rapid antigen tests for diagnosis of variable respiratory viruses, can be useful in etiological diagnosis of community acquired lower respiratory tract infection as well specially with the proved high sensitivity and predectivity in our study.