Comparative Evaluation of cobas Influenza A/B & RSV and Simplexa Flu A/B & RSV for Rapid Detection of Influenza and Respiratory Syncytial Viruses

Abstract

We compared two molecular point-of-care tests, the cobas Influenza A/B & RSV (cobas Liat) and the Simplexa Flu A/B & RSV (Simplexa). A total of 236 respiratory specimens from patients referred for respiratory viruses testing were retrospectively evaluated; 53 specimens tested positive for each of Flu A, Flu B, and RSV, and 77 specimens tested negative based on the results of the reference method, i.e. the Seegene Allplex Respiratory Panel 1/2/3 (Seegene, Seoul, Korea). The turnaround time (TAT) was 20 min per specimen for cobas Liat and 78 min per eight specimens for Simplexa. The numbers of invalid results were one (0.4%) in cobas Liat and 10 (4.2%) in Simplexa (p < 0.05). All results were consistent with those of the reference method in cobas Liat. The sensitivity and specificity for Flu A, Flu B and RSV A were 100% with Simplexa. However, the sensitivity for RSV B was 80.0% with Simplexa, which was significantly lower than that of cobas Liat (p < 0.05). Comparison of the cycle threshold (Ct) values for RSV with Simplexa and the reference method showed the correlation as continuous variables (p < 0.001) with a higher propensity for obtaining Ct values with Simplexa, the exception being the six false negative results; their Ct values were more than 30 in the reference method. Cobas Liat showed high sensitivity for the detection of RSV B with rapid TAT, and a good workflow efficiency.