The U.S. Food and Drug Administration recently authorized emergency use of the first microarray-based H1N1 flu test. Use of the test, which remains uncleared by the agency, is authorized only for the duration of the declaration of 2009 H1N1 influenza virus as a public health emergency, which is currently set to expire on April 26, 2010.

Developed by TessArae using Affymetrix technology, the TessArray resequencing influenza A microarray detection panel (TessArray RM-Flu test) is a targeted sequencing assay. It is aided by an algorithm that relies on seasonal A/H1N1 and seasonal A/H3N2 influenza virus results.

The test, which uses throat swab samples, is authorized for use by CLIA High Complexity Laboratories that have access to Affymetrix microarray instrumentation.

The FDA previously granted EUAs to H1N1 flu tests manufactured by Roche (Basel, Switzerland), DxNA (St. George, Utah), Diatherix Laboratories (Huntsville, Ala.), Prodesse (now part of Gen-Probe), and Focus Diagnostics, the infectious disease diagnostics business of Quest Diagnostics (Madison, N.J.).

Focus's real-time reverse transcription polymerase chain reaction (rRT-PCR) diagnostic test was the first commercial H1N1 test to be granted an EUA. The FDA had previously granted the Centers for Disease Control and Prevention two EUAs for diagnostic tests.

For more on H1N1 flu testing, see the January issue of Diagnostic Testing and Technology Report.