FDA Approves New Flu Test
First rapid molecular test to differentiate influenza A and B
The FDA has cleared the Alere Influenza A & B test — the first molecular test to detect and differentiate influenza A and B viruses in less than 15 minutes — for marketing in the U.S.
The test’s clinical performance was established in a prospective study conducted at U.S. sites during the 2012–2013 flu season. In this investigation, 585 prospective nasal swab specimens, collected from patients presenting with flu-like symptoms, were evaluated with the Alere test, and the results were compared with viral culture. All specimens generating discrepant results between the Alere Influenza A & B test and culture were further evaluated using an FDA-approved reverse transcription polymerase chain reaction (RT-PCR) assay to confirm the specimens’ influenza status.
Molecular testing involves the extraction and analysis of DNA or RNA strands to detect sequences associated with viral and bacterial causes of infections. According to its manufacturer (Alere Inc.), the Alere Influenza A & B test is the first molecular diagnostic test that delivers actionable, accurate results in less than 15 minutes. Unlike PCR testing, the Alere test’s proprietary isothermal nucleic acid amplification technology (iNAT) does not require complex thermo cycling or DNA purification, and can therefore deliver PCR-caliber results more quickly. Tests for Streptococcus A, Clostridium difficile, respiratory syncytial virus,and chlamydia/gonorrhea are currently in development.
The Alere Influenza A & B Test is an in vitro immunochromatographic assay for the qualitative detection of influenza A and B nucleoprotein antigens in nasal swab specimens collected from symptomatic patients. It is intended to aid in the differential diagnosis of influenza A and B viral infections.
Negative results do not preclude influenza virus infection and should not be used as the sole basis for treatment or other management decisions.
The Alere Influenza A & B test was used to evaluate 55 archived respiratory specimens confirmed to be positive for the 2009 H1N1 influenza virus by an FDA-cleared RT-PCR assay. Overall, the test detected 45% (25/55) of the RT-PCR assay-positive specimens. The detection rates were 94% (16/17) with the higher-titer specimens and 24% (9/38) with the lower-titer specimens.
Influenza is a highly contagious, acute viral infection of the respiratory tract. It is a communicable disease that is easily transmitted through the coughing and sneezing of aerosolized droplets containing live virus. Influenza outbreaks occur each year during the fall and winter months. Type A influenza viruses are typically more prevalent than type B viruses and are associated with most serious influenza epidemics, while type B influenza infections are usually more mild.