Comparison of a singleplex real-time RT-PCR assay and multiplex respiratory viral panel assay for detection of influenza "A" in respiratory specimens.
BACKGROUND
Evaluation of different molecular tests for the detection of pandemic (H1N1) 2009 virus is important before the next wave of the pandemic.


OBJECTIVE
To compare a hydrolysis probe-based real-time RTPCR assay recommended by the CDC to the xTAG respiratory viral panel (RVP) (Luminex Molecular Diagnostics) for the detection of influenza A.


METHODS
Eleven thousand eight hundred and ninety-eight respiratory specimens were tested by the real-time RT-PCR and RVP assays for the detection of influenza A. The distribution of seasonal H1, H3 and pandemic H1N1 subtypes in these specimens was compared.


RESULTS
The RVP assay was generally unable to identify influenza A–positive samples with a low viral load, whereas the real-time RT-PCR assay detected most of these samples resulting in a subset of specimens that could not be confirmed as either seasonal or pandemic influenza A subtypes.


CONCLUSIONS
When the prevalence of influenza A is high, the CDC recommended real-time RT-PCR has significant advantages as a frontline assay, namely higher sensitivity and shorter time to reporting a result. Anticipated scenarios would be during the peaks of the pandemic and episodes of seasonal influenza. Furthermore, the better sensitivity of the RT-PCR makes it the preferred assay to detect influenza in patients with severe respiratory disease tested late in their clinical course. If pandemic (H1N1) 2009 virus is not the dominant virus and there is a high proportion of other respiratory viruses circulating, laboratories will be faced with the decision to use the RVP assay for the detection of pandemic (H1N1) 2009 virus.
Provincial Laboratory for Public Health (Microbiology), Calgary Site, AB, Canada. K.Pabbaraju@provlab.ab.ca
Kanti
K
Pabbaraju
Sallene
S
Wong
Bonita
B
Lee
Raymond
R
Tellier
Kevin
K
Fonseca
Marie
M
Louie
Steven J
SJ
Drews
D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype / Q000235:genetics / Q000302:isolation & purification*; D007251:Influenza, Human / Q000175:diagnosis*; D009305:Nasopharynx / Q000821:virology*; D058873:Pandemics; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods*; D012680:Sensitivity and Specificity
J Clin Virol. 2009 Jul;45(3):191-5
19540158
N Engl J Med. 2009 Jun 18;360(25):2605-15
19423869
J Clin Virol. 2007 Nov;40 Suppl 1:S36-8
18162253
J Clin Virol. 2009 Jul;45(3):196-9
19540799
J Clin Microbiol. 2009 Sep;47(9):2812-7
19571025
J Clin Virol. 2007 Nov;40 Suppl 1:S39-46
18162254
J Virol Methods. 2009 Dec;162(1-2):184-7
19682498
J Clin Microbiol. 2007 Sep;45(9):2965-70
17596360
J Clin Microbiol. 2009 Nov;47(11):3714-6
19741076
Clin Chem. 2009 Aug;55(8):1555-8
19439731
J Clin Microbiol. 2000 Nov;38(11):4096-101
11060074
J Clin Virol. 2010 Jan;47(1):34-7
19857993
Euro Surveill. 2009 Sep 10;14(36):
19758541
J Clin Virol. 2009 Jul;45(3):200-2
19515609
J Clin Microbiol. 2009 Nov;47(11):3454-60
19726603