Comparison of the NOW Influenza A & B, NOW Flu A, NOW Flu B, and Directigen Flu A+B assays, and immunofluorescence with viral culture for the detection of influenza A and B viruses.
To evaluate the Binax NOW Influenza A & B combination assay, we tested upper respiratory tract samples in parallel with the Binax NOW Flu A and Binax NOW Flu B assays, the Becton-Dickinson Directigen Flu A+B assay, and immunofluorescence, and the results were compared with viral culture. Of the 521 samples tested, influenza A was cultured from 113 and influenza B from 6. There were no significant differences in the performance of all rapid antigen tests, with sensitivities of 53% to 59% for detecting influenza A compared with culture and immunofluorescence (80%). The sensitivities for all rapid tests were significantly higher for nasopharyngeal samples than for throat swabs. The Binax NOW Influenza A & B assay performed as well as other rapid assays. Commercial antigen detection assays are useful tools for the rapid diagnosis of influenza; however, confirmatory testing is always recommended. The use of nasopharyngeal samples for all rapid detection methods should be strongly encouraged.
Smit
Marita
M
Canterbury Health Laboratories, Christchurch, New Zealand.
Beynon
Kirsten A
KA
Murdoch
David R
DR
Jennings
Lance C
LC
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000956:Antigens, Viral / Q000032:analysis*; D002648:Child; D002675:Child, Preschool; D005260:Female; D005455:Fluorescent Antibody Technique; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D009980:Influenza A virus / Q000302:isolation & purification*; D009981:Influenza B virus / Q000302:isolation & purification*; D007251:Influenza, Human / Q000175:diagnosis* / Q000821:virology; D008297:Male; D008875:Middle Aged; D009305:Nasopharynx / Q000821:virology; D010614:Pharynx / Q000821:virology; D011237:Predictive Value of Tests; D011933:Reagent Kits, Diagnostic; D012680:Sensitivity and Specificity; D013997:Time Factors; D014776:Virus Cultivation
D000956:Antigens, Viral; D011933:Reagent Kits, Diagnostic