Annals of Clinical Microbiology, The official Journal of the Korean Society of Clinical Microbiology

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Weeks in Review

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Indexed in KCI, KoreaMed, Synapse, DOAJ
Open Access, Peer Reviewed
pISSN 2288-0585 eISSN 2288-6850
Original article

Comparison of Rapid Antigen Test and Real-Time Reverse Transcriptase PCR for Diagnosing Novel Swine Influenza A (H1N1)

Aerin Kwon, Jae-Seok Kim, Han-Sung Kim, Wonkeun Song, Ji-Young Park, Hyoun Chan Cho, Kyu Man Lee

Department of Laboratory Medicine, Hallym University College of Medicine, Seoul, Korea

Corresponding to Jae-Seok Kim, E-mail: jaeseok@hallym.or.kr

Ann Clin Microbiol 2010;13(3):109-113. https://doi.org/10.5145/KJCM.2010.13.3.109
Copyright © Korean Society of Clinical Microbiology.

Abstract

Background: Novel swine influenza (H1N1) was first identified in Mexico in April 2009. Because of its high infectivity and worldwide distribution, a rapid and efficient screening test is necessary. Here we evaluated the usefulness of a rapid antigen test currently in use, compared to real-time RT-PCR (rRT-PCR) as a screening test for detection of novel swine influenza (H1N1). 

Methods: A total of 1,228 patients who visited Hallym University Kangdong Sacred Heart Hospital with influenza-like illness between 14 August 2009 and 30 September 2009, and were tested by both rapid antigen and rRT-PCR tests, were enrolled in this study. 

Results: Sensitivity, specificity, predictive value of a positive test, and predictive value of a negative test for the rapid antigen test were 30.5%, 99.2%, 86.4% and 90.1%, respectively. Fifty-one (4.2%) patients were positive for both rapid antigen test and rRT- PCR, and 1,053 (85.7%) were negative for both rapid antigen test and rRT-PCR. A total of 124 (10.1%) patients showed a discrepancy between the two tests. Among them, 116 (9.4%) were only positive for rRT-PCR and 8 (0.7%) were only positive for the rapid antigen test. The latter 8 patients all showed negative H1/M2 results in rRT-PCR. There were significant differences in detection rates of the rapid antigen test between different H1 Ct (threshold cycle) interval groups and for different age groups (P<0.05). 

Conclusion: Although the rapid antigen test is easy to perform and provides fast results, its limits as a screening test for detection of novel swine influenza (H1N1) due to its low sensitivity compared to rRT- PCR need to be considered in practical situations. (Korean J Clin Microbiol 2010;13:109-113)

Keywords

Novel swine influenza, H1N1, Rapid antigen test, Real-time PCR, Sensitivity