摘要
Background:Seasonal influenza resurged in China in February 2023,causing a large number of hospitalizations.While influenza epidemics occurred across China during the coronavirus disease 2019(COVID-19)pandemic,the relaxation of COVID-19 containment measures in December 2022 may have contributed to the spread of acute respiratory infections in winter 2022/2023.Methods:Using a mathematical model incorporating influenza activity as measured by influenza-like illness(ILI)data for northern and southern regions of China,we reconstructed the seasonal influenza incidence from October 2015 to September 2019 before the COVID-19 pandemic.Using this trained model,we predicted influenza activities in northern and southern China from March to September 2023.Results:We estimated the effective reproduction number Re as 1.08[95%confidence interval(CI):0.51,1.65]in northern China and 1.10(95%CI:0.55,1.67)in southern China at the start of the 2022-2023 influenza season.We estimated the infection attack rate of this influenza wave as 18.51%(95%CI:0.00%,37.78%)in northern China and 28.30%(95%CI:14.77%,41.82%)in southern China.Conclusions:The 2023 spring wave of seasonal influenza in China spread until July 2023 and infected a substantial number of people.
基金
Supported by grants from the AIR@InnoHK Programme of the Innovation and Technology Commission of the Government of the Hong Kong Special Administrative Region and the Theme-based Research Scheme(T11-712/19-N)of the Research Grants Council of the Hong Kong SAR Government.
