Influenza Division, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia 30333, USA.
Clin Infect Dis. 2011 Jan 1;52 Suppl 1:S27-35. doi: 10.1093/cid/ciq009.
The emergence in April 2009 and subsequent spread of the 2009 pandemic influenza A (H1N1) virus resulted in the first pandemic of the 21st century. This historic event was associated with unusual patterns of influenza activity in terms of the timing and persons affected in the United States throughout the summer and fall months of 2009 and the winter of 2010. The US Influenza Surveillance System identified 2 distinct waves of pandemic influenza H1N1 activity--the first peaking in June 2009, followed by a second peak in October 2009. All influenza surveillance components showed levels of influenza activity above that typically seen during late summer and early fall. During this period, influenza activity reached its highest level during the week ending 24 October 2009. This report summarizes US influenza surveillance data from 12 April 2009 through 27 March 2010.
2009 年 4 月，甲型 H1N1 流感大流行病毒的出现和随后的传播导致了 21 世纪的第一次大流行。这一历史性事件与美国在 2009 年夏季和秋季以及 2010 年冬季流感活动的时间和受影响人群的不同寻常模式有关。美国流感监测系统确定了 2 波甲型 H1N1 大流行流感活动——第一波在 2009 年 6 月达到高峰，随后在 2009 年 10 月出现第二波高峰。所有流感监测组成部分显示，流感活动水平高于通常在夏末和初秋看到的水平。在此期间，流感活动在 2009 年 10 月 24 日当周达到最高水平。本报告总结了 2009 年 4 月 12 日至 2010 年 3 月 27 日期间美国的流感监测数据。
