Impact of the COVID-19 related border restrictions on influenza and other common respiratory viral infections in New Zealand.

BACKGROUND: New Zealand's (NZ) complete absence of community transmission of influenza and respiratory syncytial virus (RSV) after May 2020, likely due to COVID-19 elimination measures, provided a rare opportunity to assess the impact of border restrictions on common respiratory viral infections over the ensuing 2 years. METHODS: We collected the data from multiple surveillance systems, including hospital-based severe acute respiratory infection surveillance, SHIVERS-II, -III and -IV community cohorts for acute respiratory infection (ARI) surveillance, HealthStat sentinel general practice (GP) based influenza-like illness surveillance and SHIVERS-V sentinel GP-based ARI surveillance, SHIVERS-V traveller ARI surveillance and laboratory-based surveillance. We described the data on influenza, RSV and other respiratory viral infections in NZ before, during and after various stages of the COVID related border restrictions. RESULTS: We observed that border closure to most people, and mandatory government-managed isolation and quarantine on arrival for those allowed to enter, appeared to be effective in keeping influenza and RSV infections out of the NZ community. Border restrictions did not affect community transmission of other respiratory viruses such as rhinovirus and parainfluenza virus type-1. Partial border relaxations through quarantine-free travel with Australia and other countries were quickly followed by importation of RSV in 2021 and influenza in 2022. CONCLUSION: Our findings inform future pandemic preparedness and strategies to model and manage the impact of influenza and other respiratory viral threats.

Comparison of the fast track diagnostics respiratory 21 and Seegene Allplex multiplex polymerase chain reaction assays for the detection of respiratory viruses.

BACKGROUND: Real-time multiplex PCR assays are increasingly used for respiratory virus detection, and offer automated analysis in a closed tube system, but they have the disadvantage of low-throughput due to multiplexing limitations. In this study, the established fast-track respiratory 21 assay (FTD) (fast-track diagnostics, Junglinster Luxembourg) was compared to the new Seegene Allplex assay (Seegene) (Seegene Inc. Seoul, Korea) which offers greater multiplexing as multiple targets can be detected in each fluorescence channel. The Seegene Allplex assay is quicker to perform than previous Seegene respiratory multiplex assays. MATERIALS AND METHODS: The assays were evaluated using 199 mostly upper respiratory tract samples. RESULTS: A respiratory pathogen was found in 127/199 (63.8%) of samples by the FTD assay and 123/199 (61.8%) using the Seegene assay. Kappa agreement was between 0.87 and 1 for all targets except human bocavirus and adenovirus. CONCLUSION: Although the performance of the assays were similar, the Seegene assay had the advantage of simultaneous detection of two gene targets for each of the common Influenza A subtypes, improved throughput of 30 samples per run and automated result analysis. The FTD assay could only test 17 samples per run but validation for use on several different real-time thermal cyclers made it easier to integrate into an existing laboratory system. Both assays were cost effective compared to in-house multiplex PCR respiratory virus screening.