Comparison of Nasopharyngeal Aspirates and Nasal Swabs for the Detection of Respiratory Viruses by Multiplex RT-PCR / 소아알레르기및호흡기학회지

ABSTRACT

PURPOSE: Although the nasopharyngeal aspirate (NPA) is more commonly used because of relatively higher accuracy, the nasal swab (NS) is a less painful and easier method than NPA. A few recent reports have shown that NS is more effective than NPA for the detection of respiratory virus using immunofluorescence or viral culture. The objective of the present study was to compare the results of NPA and NS sampling specimens in children for respiratory viruses detection using multiplex RT-PCR. METHODS: From December 2008 to June 2009 Paired NPA and NS specimens were collected from 250 children admitted with symptoms of acute respiratory infections at the Department of Pediatrics, Soonchunhyang University Cheonan Hospital, Cheonan, Korea. The sensitivity and agreement of virus detection between NPA and NS using multiplex RT-PCR were compared and analyzed. RESULTS: The median age of the subjects was 1.3 years (range, 20 days to 16.5 years), and 228 patients (91.2%) were under the age of 5 years. The agreement of virus detection between NPA and NS was excellent (Cohen's kappa >0.8) for parainfluenza virus type 3 or substantial (0.6 to 0.8) for rhinovirus A, RSV A and RSV B, moderate (0.4 to 0.6) for adenovirus and metapneumovirus and poor (<0.4) for influenza A. The overall sensitivity of detection of respiratory viruses was significantly higher in NPA (0.96) than in NS (0.59, P<0.05). CONCLUSION: We recommend NPA may be more accurate specimen for detection of respiratory viruses in hospitalized children. NS might be used in limited cases at a office setting or for larger epidemiological studies. However, results obtained from NS for influenza virus type A, metapneumovirus and adenovirus, should be interpreted carefully.