Clinical performance of the 3M Rapid Detection Flu A+B Test compared to R-Mix culture, DFA and BinaxNOW Influenza A&B Test.

BACKGROUND

The rapid diagnosis of influenza allows for prompt patient management and the initiation of appropriate infection control measures to reduce spread in healthcare settings.

OBJECTIVE

To evaluate the clinical performance of the 3M Rapid Detection Flu A+B Test (3MA+B) as compared to R-Mix cell culture, direct immunofluorescence assay (DFA) and the BinaxNOW A&B Influenza Test (BinaxNOW).

STUDY DESIGN

Five hundred fresh respiratory samples, collected from patients aged 5 days to 99 years with respiratory symptoms, were tested by R-Mix culture, DFA, 3MA+B and BinaxNOW. Analytical sensitivity of 3MA+B was compared to BinaxNOW using replicates of serially diluted clinical samples positive for influenza A or B.

RESULTS

Sensitivity, specificity, PPV and NPV for the detection of influenza A and B, respectively, were for R-Mix (96.9%, 100%, 100%, 99.3%; 98.1%, 100%, 100%, 99.8%), DFA (80.4%, 99.2%, 96.1%, 95.3%; 74%, 100%, 100%, 97%), 3MA+B (70.1%, 99.8%, 98.6%, 93%; 86.5%, 98.7%, 88.2%, 98.4%) and BinaxNOW (46.4%, 100%, 100%, 88.6%; 34.6%, 100%, 100%, 93%). R-Mix, DFA and 3MA+B were significantly (P<or=0.0001) more sensitive than BinaxNOW for the detection of both influenza A and B. The analytical sensitivity of 3MA+B was greater than BinaxNOW. Excessive blood in samples may cause 3MA+B false positive influenza B results.

CONCLUSIONS

The 3MA+B provided superior results compared to BinaxNOW. The 3MA+B Reader eliminated user misinterpretation and provided quality control and result documentation. The improved sensitivity and easy of use makes 3MA+B an effective first line triage test for emergency departments, clinics and rapid response laboratories.