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

Abstract

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.