Evaluation of the Simplexa Flu A/B and RSV test for the rapid detection of influenza viruses.

Recently, various molecular systems have been introduced for the detection of influenza viruses. Among these, the Simplexa Flu A/B and respiratory syncytial virus (RSV) test can provide results in approximately 2 hr. Nasopharyngeal swabs from 241 patients (influenza A, n = 81; influenza B, n = 80; influenza A and influenza B mixed, n = 1; influenza A and RSV A mixed, n = 2; and influenza and RSV negative, n = 77) were analyzed using the Simplexa Flu A/B and RSV test, a conventional reverse-transcription polymerase chain reaction (RT-PCR) assay, and a real-time RT-PCR assay. Compared to conventional RT-PCR, the Simplexa test had respective sensitivities and specificities of 100% and 100% for influenza A and 100% and 99.4% for influenza B with extracted RNA samples, and 91.7% and 99.4% for influenza A, and 97.5% and 98.1% for influenza B with unprocessed patient specimens. All RSV A specimens were successfully detected by the Simplexa test using both extracted RNA samples and unprocessed patient specimens. The real-time RT-PCR assay had respective sensitivities and specificities of 96.4% and 99.4% for influenza A, and 98.8% and 99.4% for influenza B. The Simplexa test was effective at detecting influenza viruses from extracted RNA samples as well as from unprocessed patient specimens. The assay was not only simple and rapid for influenza detection, but the performance was also comparable to that of other conventional molecular methods.