Challenges and Strategies for Influenza Response After COVID-19 Pandemic

After the World Health Organization(WHO)declared the coronavirus disease 2019(COVID-19)pandemic in March 2020,the implementation of the most effective interventions became a paramount public health priority in the global response to the COVID-19 pandemic,especially before vaccines were available.Several studies have demonstrated that nonpharmaceutical interventions(NPIs),such as social distancing,wearing facemasks,and school closures,can substantially control the transmission of respiratory infections,including severe acute respiratory syndrome,pandemic H1N1 in 2009,and the COVID-19 pandemic.[1–3]However,various respiratory infections have become more prevalent since the COVID-19 pandemic.Since 2021,the incidence of respiratory syncytial virus(RSV)has rapidly increased in numerous countries,including the United States,[4]Australia,[5]England,[6]Italy,[7]Germany,[8]and Switzerland.[9]In December 2022,5 European countries,including France and the United Kingdom。

SARS-CoV-2 Surveillance Through China Influenza Surveillance Information System—China,December 1,2022 to February 12,2023

Introduction:The World Health Organization(WHO)proposed using influenza surveillance systems to carry out coronavirus disease 2019(COVID-19)surveillance due to the similarity between the two diseases in some respiratory symptoms.To assess the prevalence of COVID-19,we analyzed the influenzalike illness(ILI)and positive rate of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)detections in ILI patients reported to the influenza Surveillance Information System(CNISIS)since late 2022.Methods:Data related to ILI were reported by national surveillance sentinel hospitals.Positive testing for SARS-CoV-2 and influenza viruses was conducted using real-time reverse transcription polymerase chain reaction(rRT-PCR)detection by the national influenza surveillance network laboratories.Surveillance data were reported to CNISIS.Results:Beginning on December 12,2022(Week 50),the ILI percentage increased dramatically,peaking in Week 51 at 12.1%.Subsequently,the ILI percentage began to decline rapidly from Week 52,2022,and by Week 6,2023(February 6-12),the ILI and ILI percentage had returned to the levels observed at the beginning of December 2022.From December 1,2022 to February 12,2023,115,844 specimens were tested for both SARS-CoV-2 and influenza virus.Of these,30,381(26.2%)were positive for SARSCoV-2 and 1,763(1.5%)were positive for influenza virus.The positive rate of SARS-CoV-2 tests peaked at 74.1%around December 23 and 25.Conclusions:Sentinel-based surveillance,previously established for influenza,is an effective way to track the circulation trend of SARS-CoV-2 during community-level epidemics.There was no coprevalence of SARS-CoV-2 and influenza virus during the outbreak of SARS-CoV-2,even during the winter influenza season.However,it is important to remain vigilant for the potential rise of influenza activities following the COVID-19 epidemic.