Comparing the Cobas Liat Influenza A/B and RSV assay with multiplex nucleic acid testing.

Influenzavirus and respiratory syncytial virus (RSV) detection with short turn-around-time (TAT) is pivotal for rapid decisions regarding treatment and infection control. However, negative rapid testing results may come from poor assay sensitivity or from influenza-like illnesses caused by other community-acquired respiratory viruses (CARVs). We prospectively compared the performance of Cobas Liat Influenza A/B & RSV assay (LIAT) with our routine multiplexNAT-1 (xTAG Respiratory Pathogen Panel, Luminex) and multiplexNAT-2 (ePlex-RPP; GenMark) using 194 consecutive nasopharyngeal swabs from patients with influenza-like illness during winter 2017/18. Discordant results were reanalyzed by specific in-house quantitative NAT. LIAT was positive for Influenza-A, -B, and RSV in 18 (9.3%), 13 (6.7%), and 55 (28.4%) samples, and negative in 108 samples. Other CARVs were detected by multiplexNAT in 66 (34.0%) samples. Concordant results for influenza and RSV were seen in 190 (97.9%), discordant results in 4 (2.1%), which showed low-level RSV (<40000 copies/mL). Sensitivity and specificity of LIAT for Influenza-A, -B, and RSV was 100%, 100% and 100%, and 100%, 99.5% and 100%, respectively. The average TAT of LIAT was 20min compared to 6h and 2h for the multiplexNAT-1 and -2, respectively. Thus, LIAT demonstrated excellent sensitivity and specificity for influenza and RSV, which together with the simple sample processing and short TAT renders this assay suitable for near-patient testing. This article is protected by copyright. All rights reserved.