Abstract
Although infections with the novel pandemic 2009 influenza A (H1N1) virus (A/H1N1/2009) appear to be relatively mild during the summer months of circulation ('off season'), there has been significant morbidity and hospitalization and several fatal cases. Thus, rapid detection of A/H1N1/2009 is crucial. In contrast to seasonal influenza, where point-of-care (POC) rapid antigen tests and direct fluorescent antibody (DFA) staining ensure rapid detection, diagnosis of A/H1N1/2009 has so far been based mainly on RT-PCR due to lack of sensitivity of the other non-molecular methods. This study is aimed to evaluate the Xpert FluA/H1N1 test (Cepheid (R)), rapid molecular test for influenza A virus including A/H1N1/2009 for the detection of the recently emerged swine influenza A (H1N1) and compare it with RT-PCR. A total of 386 respiratory samples were tested in parallel using Cepheid Xpert FluA and compared with RT-PCR. We determined the analytical performance characteristics (sensitivity, specificity) of the xpert test using RT-PCR as the gold standard. RESULTS: Xpert Flu A Panel detected A(H1N1) seasonal and 2009 pandemic, A(H3N2), A(H5N2), A(H5N1) and A(H7N7) viruses and correctly subtyped A(H1N1) 2009 virus. Of 386 samples, 53 samples were positive by the two methods, RT-PCR detected 2 samples that were negative by Xpert Flu. Analytical sensitivity was comparable to RT-PCR. The Xpert Flu A Panel is the first commercially available rapid molecular test for detection of influenza A and B viruses and at the same time, it can determine H1 2009 subtype. The test has comparable sensitivity compared with RT-PCR and high specificity. Therefore, it represents a useful rapid test for molecular detection of Flu A and B viruses and can also rule out H1N1.