Comparison of Luminex NxTAG Respiratory Pathogen Panel and xTAG Respiratory Viral Panel FAST Version 2 for the Detection of Respiratory Viruses

Lee, Chun Kiat; Lee, Hong Kai; Ng, Christopher Wei Siong; Chiu, Lily; Tang, Julian Wei-Tze; Loh, Tze Ping; Koay, Evelyn Siew-Chuan

We assessed the clinical performance of the new NxTAG RPP against that of the xTAG RVP FAST v2 using a representative panel of viral pathogens and negatives. Notably, the seasonal influenza A/H1N1 virus was not detected in our local population, and was not included in this study. This strain appears to have been completely replaced by the pandemic influenza A/ H1N1/2009 virus since 2009/2010 [8] . Overall, both assays showed comparable sensitivity and specificity for all viral targets, except for the influenza A/H3N2 virus. Notably, the xTAG RVP FAST v2 showed poor performance in influenza A/H3N2 subtyping, which may be due to primer mismatches. To the best of our knowledge, only one study has compared the performance of the NxTAG RPP with that of the xTAG RVP FAST v2; however, missed detection of influenza A/H3N2 was not reported [7] . It is unclear whether the missed detection by the xTAG RVP FAST v2 was related to the variant H3N2 virus reported by the Centers for Disease Control and Prevention (Atlanta) recently [9, 10] . Nonetheless, the inability to simultaneously detect and subtype these H3N2 viruses is a major hindrance for clinical laboratories to return test results within established turn-around-time. The influenza A/H3N2 virus is a clinically significant respiratory pathogen. Therefore, the ability to rapidly provide subtype information is important during an outbreak or in epidemiologic investigations. By contrast, the influenza A/H3N2 primers in the NxTAG RPP have been updated to detect these untypable strains. Our study suggests that existing xTAG RVP FAST v2 users should switch to the NxTAG RPP, which has better sensitivity for influenza A/H3N2, without a significant drop in sensitivity for the other respiratory viral targets.