Department of Epidemiology and Biostatistics, School of Public Health, Peking University, Beijing, China.
J Med Virol. 2023 Jun;95(6):e28888. doi: 10.1002/jmv.28888.
Nonpharmaceutical interventions to limit the coronavirus disease 2019 (COVID-19) pandemic might reduce the transmission of influenza viruses and disrupt the typical seasonality of influenza. However, changes in epidemiology and seasonal patterns of influenza remain unknown in China during the COVID-19 pandemic. Data on influenza-like illness (ILI) and influenza cases between surveillance Week 14 in 2010 and Week 6 in 2023 and ILI outbreaks between Week 14 in 2013 and Week 6 in 2023 were collected from the weekly reports of the Chinese National Influenza Center. A total of 32 10 735 ILI specimens were tested between Week 14 in 2010 and Week 6 in 2023 in China, with 12.4% of specimens positive for influenza. The influenza-positive percentage ranged from 11.8% to 21.1% in southern China and 9.5% to 19.5% in northern China between the 2010/2011 and 2019/2020 influenza seasons. The influenza-positive percentage was 0.7% in southern China and 0.2% in northern China in the 2020/2021 season. An increasing trend in influenza-positive percentage was observed in southern China in Weeks 18-27 in the 2022/2023 season, with a peak of 37.3%. A total of 768 ILI outbreaks reported in southern China in Weeks 14-26 in the 2022/2023 season were much more than those in the same period in the 2020/2021 and 2021/2022 seasons. In summary, seasonal influenza shifted from low to out-of-season epidemics during the COVID-19 pandemic in China, especially in southern China. Influenza vaccination and everyday preventive actions, such as mask wearing, appropriate air exchange, and good hand hygiene practices, are essential for the prevention of influenza virus infection during the COVID-19 pandemic.
非药物干预措施限制 2019 年冠状病毒病（COVID-19）大流行可能会减少流感病毒的传播，并打乱流感的典型季节性。然而，在中国 COVID-19 大流行期间，流感的流行病学和季节性模式变化仍不清楚。从中国国家流感中心每周报告中收集了 2010 年监测第 14 周至 2023 年第 6 周期间的流感样疾病（ILI）和流感病例以及 2013 年第 14 周至 2023 年第 6 周期间的 ILI 暴发的数据。在中国，2010 年第 14 周至 2023 年第 6 周期间共检测了 3210735 份 ILI 标本，其中 12.4%的标本流感呈阳性。在 2010/2011 至 2019/2020 流感季节期间，中国南方地区的流感阳性率在 11.8%至 21.1%之间，北方地区的流感阳性率在 9.5%至 19.5%之间。2020/2021 季节，中国南方地区的流感阳性率为 0.7%，北方地区为 0.2%。在 2022/2023 季节的第 18-27 周，中国南方地区的流感阳性率呈上升趋势，峰值为 37.3%。2022/2023 季节第 14-26 周期间，中国南方地区共报告了 768 起 ILI 暴发，明显多于 2020/2021 和 2021/2022 同期。总之，在中国 COVID-19 大流行期间，季节性流感从低流行转变为季节性外流行，尤其是在南方地区。流感疫苗接种和日常预防措施，如戴口罩、适当通风和良好的手部卫生习惯，对于 COVID-19 大流行期间预防流感病毒感染至关重要。
