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Evaluation of three commercial Rapid Antigen assays for the detection of influenza An/H1N1

Abstract number: P1101

Perez J., Culebras E., Alvarez-Buylla A., Betriu C., Picazo J.

Objectives: Pandemic influenza An/H1N1 emerged in mid-April 2009 leaving laboratories around the world scrambling to establish a diagnostic test to detect this novel influenza virus. Reverse-transcriptase polymerase chain reaction (RT-PCR) is considered the reference test for diagnosis of influenza because of its high sensitivity and specificity as well as its rapid turnaround time. However, RT-PCR is expensive and requires trained expertise and batch testing, which delays reporting. Rapid influenza antigen test might prove useful, because they have a fast turnaround time (10–15 min) and require minimal training to perform. We evaluated three rapid antigen detection test for their ability to detect influenza An/H1N1. We calculated the sensitivity for each test.

Materials and Methods: We tested 3 different rapid influenza antigen tests for pandemic infuenza An/H1N1 virus. We checked BinaxNow® Influenza A&B (CV. Inverness Medical), Influ A&B Uni-Strip (IAB. Materlab) and QuickVue® Influeza A+B test (QV. Biomerieux). Twenty two nasopharyngeal specimens that were positive for pandemic influenza A virus by RT-PCR (Roche) were included. We included samples with viral load between 1×102 and 1×108 copies/ml. Only 5 samples were tested for the IAB test.

Results: Sensitivities of test were low to moderate: BinaxNow® Influenza A&B (Inverness Medical) 3 of 22 specimens and QuickVue® Influeza A+B test (Biomerieux) 10 of 22 specimens. The detection limit of both systems was 1×106 copies/ml and 1×104 copies/ml respectively. IAB test was positive only in samples with >1times;106 copies/ml. All samples with viral load below 9×103 copies/ml were negative with all tests.

Conclusions:

1QV test showed the highest sensitivity of the evaluated tests.

2Positive results for rapid antigen tests correlates with higher viral load.

3Negative rapid influenza diagnostic test does not rule out infection with novel influenza A (H1N1) virus.

4Rapid influenza antigen tests can be used to avoid the RT-PCR assay in samples positive for the rapid tests.

Session Details

Date: 10/04/2010
Time: 00:00-00:00
Session name: Abstracts 20th European Congress of Clinical Microbiology and Infectious Diseases
Subject:
Location: Vienna, Austria, 10 - 13 April 2010
Presentation type:
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