US Food and Drug Administration (FDA) regulators are proposing to reclassify some Influenza Antigen Detection Test Systems into a higher-risk category than the systems now inhabit, citing potential for the devices to fail to detect newer versions of the virus.

Background

The devices, which are used to detect the presence of influenza in a clinical sample, were Classified as low-risk Class I medical devices in 1982. Class I devices only require the company to adhere to general controls and do not require a premarket submission such as a 510(k) or premarket application.

As FDA explains, in 1982, "Influenza tests conceived to fall under this regulation were laboratory methods to detect antibodies that develop in response to influenza infection while the detection of the influenza virus itself was done primarily by viral culture. As enzyme immunoassay technology developed, tests capable of detecting viral proteins (antigens) directly in human respiratory samples began to come to FDA for clearance."

Since then, FDA notes that "methods utilizing antigens and antibodies as components of an influenza detection device" have been approved or cleared for use, and that 12 of those tests remain on the market today.

And while those devices are easier to use and provide the user with faster results than older influenza detection tests, they have been known to fail. FDA pointed to the 2009 flu pandemic, which was notable for the poor performance of Rapid Influenza Detection Tests (RIDTs). Misdiagnoses were common, and potentially resulted in serious and even fatal consequences for patients.

"Failure of the device to perform as indicated (producing erroneous or inaccurate results) could mislead the physician and cause inappropriate or delayed medical treatment of a patient," FDA wrote. "Failure of the test to produce accurate test results can also lead to inaccurate epidemiological information that may contribute to inappropriate public health responses and to facilitate spread of the infection in a community."

One of FDA's advisory panels recommended in 2013 that the device be reclassified as a Class II device to better reflect the special controls needed to ensure that devices are capable of detecting changes in the virus as it mutates over time.

Reclassification

FDA has now formally agreed with that assessment, and in a proposed rule published on 21 May 2014 has proposed classifying the devices as Class II, requiring the submission of a 510(k) application and subjecting the devices to special controls.

Those controls include requirements to meet at least one clinical performance criteria established by FDA, to perform annual testing with contemporary strains of the virus, and keep labeling up to date with current influenza emergency findings by FDA and other health agencies.

Federal Register Announcement