Comparison of two new generation influenza rapid diagnostic tests with instrument-based digital readout systems for influenza virus detection.
BACKGROUND
Influenza rapid diagnostic tests (RDTs) have been developed to supply scientists with more sensitive and specific techniques. Newly developed digital reader-based techniques require test evaluations before their clinical application.


METHODS
Two types of digital influenza RDTs using a digital readout system and one conventional RDT were compared using 314 nasopharyngeal swabs of influenza. The swabs originated from symptomatic individuals suspected of influenza infection, and the presence of influenza was confirmed with influenza real-time polymerase chain reaction (PCR) testing and influenza subtyping. Methods were the Sofia® Influenza A + B Fluorescence Immunoassay (FIA), which uses a portable fluorescence analyser, the BD Veritor™ System Flu A + B, which uses a colorimetric immunochromatographic method with a reflectance-based measurement digital device, and the SD Bioline assay, which is based on a traditional immunochromatographic method.


RESULTS
The Sofia® Influenza A + B system, the BD Veritor™ System Flu A + B and the SD Bioline assay showed sensitivities in relative real-time PCR results of 74.2, 73.0 and 53.9%, respectively, for influenza A, and 82.5, 72.8 and 71.0%, respectively, for influenza B. All three RDTs showed 100% specificities for influenza A and influenza B. The Sofia® Influenza A + B Fluorescence Immunoassay showed sensitive and specific results for the detection of influenza B in contrast to the BD Veritor™ System Flu A + B. The two digital RDTs showed higher sensitivity and specificity than the conventional RDT in the detection of the influenza H3 subtype.


CONCLUSIONS
Digital-based readout systems for the detection of the influenza virus can be applied for more sensitive diagnosis in clinical settings than conventional RDTs.
a Department of Laboratory Medicine, School of Medicine , Kangwon National University , Chuncheon , Korea.
S-W
SW
Ryu
b Department of Laboratory Medicine , Osan Hankook General Hospital , Osan , Korea.
J-H
JH
Lee
c Department of Laboratory Medicine, College of Medicine , Korea University , Seoul , Korea.
J
J
Kim
c Department of Laboratory Medicine, College of Medicine , Korea University , Seoul , Korea.
M-A
MA
Jang
c Department of Laboratory Medicine, College of Medicine , Korea University , Seoul , Korea.
J-H
JH
Nam
c Department of Laboratory Medicine, College of Medicine , Korea University , Seoul , Korea.
M-S
MS
Byoun
c Department of Laboratory Medicine, College of Medicine , Korea University , Seoul , Korea.
C S
CS
Lim
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D002845:Chromatography / Q000379:methods; D003124:Colorimetry / Q000379:methods; D003955:Diagnostic Tests, Routine / Q000379:methods*; D005260:Female; D006801:Humans; D007118:Immunoassay / Q000379:methods; D007223:Infant; D009980:Influenza A virus; D009981:Influenza B virus; D007251:Influenza, Human / Q000175:diagnosis*; D008297:Male; D008875:Middle Aged; D060888:Real-Time Polymerase Chain Reaction; D012680:Sensitivity and Specificity; D055815:Young Adult
Influenza; instrument-based digital readout system; rapid diagnostic test; real-time PCR