MMWR Morb Mortal Wkly Rep. 2020 Sep 18;69(37):1305-1309. doi: 10.15585/mmwr.mm6937a6.
After recognition of widespread community transmission of SARS-CoV-2, the virus that causes coronavirus disease 2019 (COVID-19), by mid- to late February 2020, indicators of influenza activity began to decline in the Northern Hemisphere. These changes were attributed to both artifactual changes related to declines in routine health seeking for respiratory illness as well as real changes in influenza virus circulation because of widespread implementation of measures to mitigate transmission of SARS-CoV-2. Data from clinical laboratories in the United States indicated a 61% decrease in the number of specimens submitted (from a median of 49,696 per week during September 29, 2019-February 29, 2020, to 19,537 during March 1-May 16, 2020) and a 98% decrease in influenza activity as measured by percentage of submitted specimens testing positive (from a median of 19.34% to 0.33%). Interseasonal (i.e., summer) circulation of influenza in the United States (May 17-August 8, 2020) is currently at historical lows (median = 0.20% tests positive in 2020 versus 2.35% in 2019, 1.04% in 2018, and 2.36% in 2017). Influenza data reported to the World Health Organization's (WHO's) FluNet platform from three Southern Hemisphere countries that serve as robust sentinel sites for influenza from Oceania (Australia), South America (Chile), and Southern Africa (South Africa) showed very low influenza activity during June-August 2020, the months that constitute the typical Southern Hemisphere influenza season. In countries or jurisdictions where extensive community mitigation measures are maintained (e.g., face masks, social distancing, school closures, and teleworking), those locations might have little influenza circulation during the upcoming 2020-21 Northern Hemisphere influenza season. The use of community mitigation measures for the COVID-19 pandemic, plus influenza vaccination, are likely to be effective in reducing the incidence and impact of influenza, and some of these mitigation measures could have a role in preventing influenza in future seasons. However, given the novelty of the COVID-19 pandemic and the uncertainty of continued community mitigation measures, it is important to plan for seasonal influenza circulation in the United States this fall and winter. Influenza vaccination of all persons aged ≥6 months remains the best method for influenza prevention and is especially important this season when SARS-CoV-2 and influenza virus might cocirculate (1).
自 2020 年 2 月中、下旬普遍认识到 SARS-CoV-2（引起 2019 年冠状病毒病（COVID-19）的病毒）在社区中的传播以来，北半球的流感活动指标开始下降。这些变化归因于与呼吸道疾病常规求医减少有关的人为变化，也归因于由于广泛实施了减轻 SARS-CoV-2 传播的措施，流感病毒传播发生了真实变化。美国临床实验室的数据表明，提交的标本数量减少了 61%（从 2019 年 9 月 29 日至 2 月 29 日期间每周中位数为 49,696 份，降至 2020 年 3 月 1 日至 5 月 16 日的 19,537 份），流感活动的阳性率（从 19.34%的中位数降至 0.33%）也下降了 98%。美国（5 月 17 日至 8 月 8 日）的季节性（即夏季）流感目前处于历史最低水平（中位数为 2020 年阳性率为 0.20%，而 2019 年为 2.35%，2018 年为 1.04%，2017 年为 2.36%）。世界卫生组织（WHO）流感网络平台报告的三个南半球国家（大洋洲的澳大利亚、南美洲的智利和南部非洲的南非）的流感数据显示，2020 年 6 月至 8 月期间的流感活动非常低，这是典型的南半球流感季节。在广泛实施社区缓解措施的国家或司法管辖区（例如，戴口罩、保持社交距离、学校关闭和远程办公），在即将到来的 2020-21 北半球流感季节，这些地区的流感传播可能很少。为应对 COVID-19 大流行而采取的社区缓解措施以及流感疫苗接种可能会有效降低流感的发病率和影响，其中一些缓解措施可能会在未来季节发挥预防流感的作用。但是，鉴于 COVID-19 大流行的新颖性以及社区缓解措施持续的不确定性，重要的是要为今年秋季和冬季美国的季节性流感流行做好计划。所有 6 个月以上人群的流感疫苗接种仍然是预防流感的最佳方法，尤其是在 SARS-CoV-2 和流感病毒可能同时流行的这个季节（1）。
