Comparison of two rapid influenza A/B test kits with reference methods showing high specificity and sensitivity for influenza A infection

Abstract

The rapid detection of influenza viruses is important for forming preventative strategies, directing initiation of anti-viral therapy, detecting potential avian influenza viruses, and excluding influenza-like pathogens, such as SARS. The ImmunoCard STAT! Flu A and B Plus test (Meridian Bioscience, Cincinnati, OH) is a new point of care (POC) test utilizing influenza-specific monoclonal antibodies for rapid diagnosis. The performance of this assay was compared to the established POC Binax NowFlu A and NowFlu B test, and the reference diagnostic standards of viral culture, indirect immunofluorescence (IFA), and RT-PCR where appropriate. Testing of nasopharyngeal aspirates (NPA) from children, throat swabs, and nasal swabs from adults indicated ImmunoCard STAT! specificity of 98% and 100% for influenza A and B, respectively in 224 specimens. The Binax test showed specificity of 99% and 100%, respectively for influenza A and B. Sensitivity results were identical for both rapid detection kits (80% and 47% for Flu A and B, respectively). Overall results were very similar for both testing devices with the advantage of ImmunoCard STAT! Flu A and B Plus test detecting influenza A and B with sharp and easy to read results.

Comparison of the BD Veritor System for Flu A+B with the Alere BinaxNOW Influenza A&B Card for Detection of Influenza A and B Viruses in Respiratory Specimens from Pediatric Patients

“…Two recent studies showed that BinaxNOW has 71% to 80% sensitivity for detecting influenza A and only 37% to 47% sensitivity for detecting influenza B in patients, compared with viral culture, indirect immunofluorescence (IFA), and real-time RT-PCR (13,14). In another retrospective study with frozen nasopharyngeal specimens from adult and pediatric patients, the authors reported sensitivities of 62.2% and 54.5% by BinaxNOW for influenza A and influenza B, respectively, compared with real-time RT-PCR (15).…”

Clinical Validation of a Point-of-Care Multiplexed In Vitro Immunoassay Using Monoclonal Antibodies (the MSD Influenza Test) in Four Hospitals in Vietnam

“…Combining the results of nasal and throat swabs did not change the sensitivity (74.0% versus 73.6%), but a larger number of patients were positive compared to the number when nasal swabs alone were used (177 versus 159). Sensitivities for influenza viruses A and B were similar, whereas previous POC test evaluations have reported lower sensitivities for influenza virus B (30 to 50%) than influenza virus A (6,7,9,14).…”

Influenza Virus

“…Virus culturing and/or IFT were predominantly used as reference method. Sensitivity of these rapid tests can be compared to that of IFT and EIA [29,30].…”