CLINICAL EVALUATION OF THE 3M RAPID DETECTION FLU A+B TEST

Introduction: Easy to use immunochromatographic methods for the detection of influenza A and influenza B can provide clinicians with rapid results.  The specificities of the assays are generally good when used during influenza season, but the tests often lack sufficient sensitivity.  Therefore, continued improvement of these test methods are desirable. This study evaluated the new 3M Rapid Detection Flu A+B Test (3M Medical Diagnostics, St. Paul, MN).  This qualitative test cartridge utilizes fluorescent-dyed latex test particles coated with anti-Influenza A and anti-Influenza B antibodies that bind to Influenza A or B antigens, respectively, if present in the sample. Detection is performed using the 3M Rapid Detection Reader.

Methods: In total, 350 respiratory samples (nasopharyngeal [NP] washes, NP aspirates or NP swabs in Universal Transport Media [UTM, Diagnostic Hybrids, Athens, OH]) collected for routine respiratory virus detection were randomly selected from patients of all age groups.  Neat sample was used for testing with the 3M device and with the BinaxNOW Influenza A+B Assay (Inverness Medical), according to each package insert. Samples were processed for direct immunofluorescence (DFA) and R-Mix cell culture (RC) (Diagnostic Hybrids).  3M test results were compared to DFA, RC and to BinaxNOW results  

Results: In total, 71 specimens (20.29%) were positive for influenza A and 37 specimens (10.57%) positive for influenza B.  The sensitivities and negative predictive values (NPV) of DFA, R-Mix culture, BinaxNOW A+B test and the 3M Rapid Influ A+B test for the detection of influenza A and B are as follows:

Conclusions: The 3M Rapid Detection Flu A+B Test is an easy and rapid (15 min) assay that provided superior detection of both influenza A and influenza B in comparison to the BinaxNOW Influenza A+B test. The use of a fluorescent reader removed the subjective nature of reading the test cards, which can lead to both false negative or false positive results.  The reader stores all internal instrument performance quality control (IQC) and external quality control data (LQC). The small printer generates a hard copy of all IQC, LQC and patient results.