To date, 21 people have been killed during the current influenza season. Early flu symptoms may resemble other less virulent viral infections; thus, a prompt diagnosis can facilitate treatment. On January 6, the Food and Drug Administration (FDA) approved the use of a molecular test designed to quickly detect the presence of the influenza virus in a nasal swab. The Alere i Influenza A & B test (Alere Inc.) can now be used in a wide variety of clinical settings, including physician’s offices, emergency rooms, clinics, and other healthcare facilities. Previously, it could only be used in a limited number of laboratories.
Flu is an illness caused by two types of influenza viruses: Type A and Type B. The infections can range from mild to severe and can sometimes lead to hospitalization and death. According to the Centers for Disease Control and Prevention (CDC), more than 200,000 individuals in the US are hospitalized from seasonal flu-related complications each year.
“Today’s decision allows the first nucleic acid-based test to be available in clinical settings that previously could not use this technology,” explained Alberto Gutierrez, Ph.D., director of the Office of In Vitro Diagnostics and Radiological Health in the FDA’s Center for Devices and Radiological Health. He added, “We expect many other simple and accurate tests using nucleic acid-based technology to be developed in the near future. Once cleared by FDA, such tests can allow health care professionals to receive test results more quickly to inform further diagnostic and treatment decisions.”
The Alere i Influenza A & B test is conducted with a nasal swab sample from an individual with signs and symptoms of flu infection. Results are available in about 15 minutes and may be performed in the presence of the patient. Negative results do not completely rule out influenza virus infection; the test is intended to assist in diagnosis together with the evaluation of other risk factors.
The FDA notes that its waiver of the test is related to CLIA, federal standards that apply to clinical laboratory testing on humans, with certain exceptions. In June 2014, the FDA first approved the Alere i Influenza A & B test as a prescription-only product to detect influenza A and B viral RNA in nasal swab samples; the agency categorized it under CLIA as moderate complexity. The type of CLIA certificate that a lab obtains depends upon the complexity of the tests it performs. CLIA regulations describe three levels of test complexity: waived tests, moderate complexity tests, and high complexity tests.
The FDA granted a waiver under CLIA for the Alere i Influenza A & B test after the manufacturer submitted data that demonstrated the test’s ease of use and low risk of false results when used by untrained operators. This is mandatory if the test is to be allowed for use outside of moderate- and high-complexity laboratories. The agency reviewed clinical study data from more than 500 patients with signs and symptoms of respiratory viral infection tested for influenza using both the Alere i Influenza A & B test and an FDA-cleared molecular comparator. The Alere i Influenza A & B test was found to have high accuracy when identifying patients with or without influenza A and influenza B by users untrained in laboratory procedures.