FluChip-8G Influenza A+B Assay

The FluChip-8G Influenza A+B Assay is a multiplex RT-PCR in vitro diagnostic test intended for the qualitative detection and differentiation of seasonal influenza A/H3N2, seasonal influenza A/H1N1pdm09, and “non-seasonal” influenza A subtypes other than seasonal H1N1pdm09 or H3N2. The assay is also intended for the qualitative detection and differentiation of the genetic lineage of human influenza B viruses as B/Victoria or B/Yamagata. The assay is designed for use on influenza nucleic acids isolated and purified from nasopharyngeal swab and nasal swab specimens from human patients with signs and symptoms of respiratory infection in conjunction with clinical and epidemiological risk factors.

This assay amplifies the hemagglutinin (HA) gene segment, neuraminidase (NA) gene segment, matrix (M) gene segment, non-structural (NS) gene segment, and nucleoprotein (NP) gene segment for detection and discrimination of influenza A, and amplifies the hemagglutinin (HA) gene segment and neuraminidase (NA) gene segment for detection and discrimination of influenza B. This assay is not intended to detect influenza C viruses.

FluChip-8G Influenza A+B Assay “non-seasonal” influenza A positive results are for the presumptive detection of influenza A subtypes other than seasonal influenza A/H1N1pdm09 or A/H3N2. The definitive identification of a “non-seasonal” influenza A case requires additional testing and confirmation procedures in consultation with the appropriate public health authorities (e.g., local or state public health departments, etc.) for whom reporting is necessary.

Negative results do not preclude influenza virus infection. FluChip-8G Influenza A+B Assay “non-seasonal” influenza A negative results, even in the context of a FluChip-8G Influenza A+B Assay positive result for seasonal influenza A/H1N1pdm09 or A/H3N2, or influenza B, do not preclude “non-seasonal” influenza A infection and should not be used as the sole basis for patient management decisions.

Performance characteristics of the FluChip-8G Influenza A+B Assay for detecting and differentiating seasonal influenza A viruses were established when seasonal influenza A/H3N2 was the predominant influenza A virus circulating in the United States. Performance characteristics may vary with other emerging seasonal influenza A viruses. Performance characteristics of the FluChip-8G Influenza A+B Assay for detecting and differentiating human influenza B genetic lineages were established when influenza B/Victoria was the predominant influenza B virus circulating in the United States.

Due to low prevalence of “non-seasonal” influenza A viruses, performance characteristics of the FluChip-8G Influenza A+B Assay for detecting “non-seasonal” influenza A viruses and distinguishing “non-seasonal” influenza A from seasonal influenza A H1N1pdm09 and H3N2 were assessed exclusively by conducting cross-validation on a total of 759 microarray images generated from bench testing contrived samples consisting of 352 unique “non-seasonal” influenza A strains representing 62 subtypes, and by bench testing contrived samples and surrogate clinical specimens consisting of 133 unique non-seasonal influenza A strains representing 46 subtypes. FluChip-8G Influenza A+B Assay performance may vary when testing “non-seasonal” influenza A strains not represented in the performance assessment.

If infection with a novel influenza A virus strain is suspected based on current clinical and epidemiological screening criteria recommended by public health authorities, specimens should be collected with appropriate infection control precautions for novel virulent influenza viruses and sent to local or state health department(s) for testing. Viral culture should not be attempted unless a BSL 3E facility is available to receive and culture specimens.