Comparative analysis of Four sample-to-answer influenza A/B and RSV nucleic acid amplification assays using adult...

The use of Sample-to-answer (STA) platforms for the detection of influenza A/B and respiratory syncytial virus (RSV) have greatly improved patient care. These diagnostic assays based on nucleic acid amplification are rapid, accurate and relatively easy to perform.

We compared four such platforms for detecting FluA, FluB, and RSV from adult respiratory specimens: Hologic Panther Fusion® Flu A/B/RSV (Fusion), Cobas® Influenza A/B & RSV (Liat), Luminex Aries® Flu A/B & RSV (Aries), and Diasorin SimplexaTM Flu A/B & RSV (Simplexa).

Nasopharyngeal (NP) swabs (n = 224) from adults were tested on these platforms and results were compared to Center for Disease Control and Prevention recommended real-time RT-PCR assay for influenza A/B and RSV. Subtyping for FluA and FluB was performed for discrepant analysis where applicable.

Of the 82 FluA, 26 FluB, 15 RSV-positive specimens tested, the positive and negative percentage agreements (PPA and NPA respectively) for FluA detection were 100/100 (Fusion), 95.1/100 (Liat), 92.5/100 (Aries), and 84.1/99.3 (Simplexa); PPA and NPA for FluB detection were 92.3/99.5 (Fusion), 96/99.5 (Liat), 100/99.5 (Aries), and 80.8/100 (Simplexa); and for RSV detection were 100/100 (Fusion), 100/100 (Liat), 88.6/99.5 (Aries), and 73.3/100 (Simplexa). 82 confirmed FluA included 23 pH1N1 and 57 H3N2 strains with 2 strains remaining untyped. Of the 26 confirmed FluB, 25 were of the Yamagata lineage and 1 of unknown lineage.

Only 2 STA platforms demonstrated >95% PPA for the detection of all three targets while all the 4 platforms demonstrated >95% NPA for FluA, FluB and RSV.