In January 2017, the U.S. Food and Drug Administration (FDA) officially reclassified antigen-based rapid influenza diagnostic tests (RIDTs) from Class I devices to Class II devices, which are subject to more rigorous performance requirements.
This decision came after years of concern about RIDT performance during severe influenza seasons, most notably the 2009 H1N1 pandemic, which resulted in 60 million cases of influenza, and more than 12,000 deaths, in the United States. The FDA’s goal for the reclassification is to improve point-of-care influenza testing by reducing misdiagnoses, thereby helping to accelerate linkage to appropriate treatment and address the significant public health burden posed by influenza.2
Every respiratory season, millions of Americans develop influenza-like illness and symptoms, leaving healthcare providers to try to differentiate influenza from other illnesses such as respiratory syncytial virus, rhinoviruses and bacterial infections.3,4
Class I RIDTs have been used to diagnose influenza infection for decades, but their limitations drove the FDA’s decision to reclassify RIDTs as Class II devices. In particular, before reclassification, the lack of ongoing assessment of influenza test performance made it difficult for clinicians to ascertain how one test compared to one another, or how any test performed across multiple respiratory seasons. This was especially troublesome for influenza testing, since circulating viruses can change and mutate rapidly and continuously.
The additional standards on testing imposed by the reclassification can also help to improve influenza infection control procedures to prevent the most at-risk populations from getting sick, reducing rates of repeat doctor visits.
As Class II devices, RIDTs must meet additional standards, called “special controls,” which are designed to ensure a high and consistent level of performance. Class II special controls call for devices to meet minimum requirements for sensitivity and specificity in comparison to FDA-accepted comparators. Additionally, manufacturers of Class II devices must collect post-marketing data, perform annual testing of their devices using currently circulating influenza strains and share performance data in the event of a declared influenza emergency.
Improving the performance of point-of-care influenza diagnostics benefits clinicians, patients and public health. According to the FDA, increasing accurate testing for influenza at the point of care will “lower the number of misdiagnosed influenza infections.” The right diagnosis – and treatment – of influenza can help to reduce the substantial morbidity, mortality and costs associated with influenza, and cut down on inappropriate antibiotic prescriptions. The additional standards on testing imposed by the reclassification can also help to improve influenza infection control procedures to prevent the most at-risk populations from getting sick, reducing rates of repeat doctor visits.
Ultimately, Class II point-of-care influenza tests should help increase clinicians’ confidence in the accuracy of test results, thereby contributing to better-informed clinical decision-making. Optimal treatment begins with appropriate, rapid diagnosis. As such, the more rigorous Class II standards, which manufacturers must fully adopt by January 12, 2018, will serve to improve health outcomes for influenza patients and help clinicians better prepare for each influenza season.