Please cite this article in press as: Miernyk K, et al. Performance of a rapid antigen test (Binax NOW ® RSV) for diagnosis of respiratory syncytial virus compared with real-time polymerase chain reaction in a pediatric population. J Clin Virol (2010), doi:10.1016/j.jcv.2010.11.011 ARTICLE IN PRESS G Model JCV-2125; No. of Pages 4 Journal of Clinical Virology xxx (2010) xxx–xxx Contents lists available at ScienceDirect Journal of Clinical Virology journal homepage: www.elsevier.com/locate/jcv Performance of a rapid antigen test (Binax NOW ® RSV) for diagnosis of respiratory syncytial virus compared with real-time polymerase chain reaction in a pediatric population  Karen Miernyk a,b,∗ , Lisa Bulkow b , Carolynn DeByle b , Lori Chikoyak c , Kimberlee Boyd Hummel b , Thomas Hennessy a , Rosalyn Singleton a,b a Alaska Native Tribal Health Consortium, 4055 Tudor Centre Dr., Anchorage, AK 99508, United States b Arctic Investigations Program, Division of Preparedness and Emerging Infections, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, 4055 Tudor Centre Dr., Anchorage, AK 99508, United States c Yukon-Kuskokwim Health Corporation, Box 528, Bethel, AK 99559, United States article info Article history: Received 7 June 2010 Received in revised form 11 November 2010 Accepted 17 November 2010 Keywords: Respiratory syncytial virus RSV diagnosis Binax NOW ® RSV Alaska Native abstract Background: Infants from Alaska’s Yukon–Kuskokwim Delta (YKD) have a high respiratory syncytial virus (RSV) hospitalization rate (104/1000/yr). Appropriate patient management requires rapid and accu- rate RSV diagnosis. Antigen-based methods are often used in clinical settings, but these tests can lack sensitivity. Objective: We compared Binax NOW ® RSV (BN) used for RSV diagnosis in the YKD hospital with a real-time polymerase chain reaction assay (RT-qPCR) used for viral surveillance. Study design: Between October 2005 and September 2007 we obtained nasopharyngeal washes (NPW) from children <3 years hospitalized with a lower respiratory tract infection. The NPW were tested using BN and RT-qPCR. Results: 79/311 (25%) children had RSV infection as determined by RT-qPCR. As compared with RT-qPCR, sensitivity and specificity of BN were 72% and 97%, respectively. The sensitivity of BN was higher in children <1 year compared with children ≥1 year (79% vs. 52%; p = 0.025), children with bronchiolitis compared with children without bronchiolitis (89% vs. 38%; p < 0.001), and children with a shorter dura- tion of symptoms before testing (0–1 (92%) vs. 2–4 (78%) vs. 5+ (65%) days; p = 0.04). The median RSV viral load in NPW positive by BN and RT-qPCR was 1.01 × 10 9 copies/mL vs. a median of 5.25 × 10 7 copies/mL for NPW positive by RT-qPCR only (p < 0.001). Conclusion: RT-qPCR is more sensitive than BN in detecting RSV infection. BN sensitivity is high in chil- dren with bronchiolitis, but the sensitivity is low when children present with a non-bronchiolitis illness, especially after a longer duration of symptoms before testing. Published by Elsevier B.V. 1. Background Respiratory syncytial virus (RSV), a negative strand RNA virus and a member of the family Paramyxoviridae, is an important cause of respiratory tract infections in children. It is estimated that approximately 100,000 hospitalizations occur from RSV infection each year in the United States (U.S.). 1 Alaska Native infants and  The findings and conclusions in this report are those of the authors and do not necessarily represent the official positions of the Centers for Disease Control and Prevention. ∗ Corresponding author at: Arctic Investigations Program, Centers for Disease Control and Prevention, 4055 Tudor Centre Dr., Anchorage, AK 99508, United States. Tel.: +1 907 602 8908; fax: +1 907 729 3429. E-mail address: kmiernyk@cdc.gov (K. Miernyk). children have higher rates of RSV hospitalization than the general U.S. population. Passive surveillance from 2001 to 2004 in Alaska’s Yukon–Kuskokwim Delta (YKD) region showed the yearly rate of RSV hospitalization of infants less than 1 year of age was four times higher than the overall U.S. infant RSV hospitalization rate (104 vs. 25–30 per 1000 infants). 2,3 Rapid and accurate diagnosis of RSV infection is crucial for appropriate patient management and infection control. 4–6 Labo- ratory diagnosis of RSV infection can be made by virus isolation, detection of viral antigens, amplification of viral nucleic acids, or a rise in RSV antibody titer. Antigen-based methods are often used in clinical settings because they are inexpensive, easy to perform and interpret, and results are available quickly. However, these tests can lack sensitivity and specificity. 7–10 Tests that amplify viral nucleic acids are highly sensitive and specific and results are avail- 1386-6532/$ – see front matter. Published by Elsevier B.V. doi:10.1016/j.jcv.2010.11.011