MMWR Morb Mortal Wkly Rep. 2012 Jun 8;61(22):414-20.
During the 2011-12 influenza season in the United States, influenza activity* occurred at low levels during October through December and increased in January and February before peaking in mid-March. Influenza A (H3N2) viruses predominated overall, but influenza A (H1N1)pdm09 (pH1N1) and influenza B viruses also circulated widely. This influenza season was mild compared with recent years, with a lower percentage of outpatient visits for influenza-like illness (ILI),† lower rates of hospitalizations, and fewer deaths attributed to pneumonia and influenza. This report summarizes influenza activity in the United States during the 2011-12 influenza season (October 2, 2011-May 19, 2012) and reports the recommendations for the components of the 2012-13 Northern Hemisphere influenza vaccine.
在 2011-12 年美国流感季节期间，流感活动*在 10 月至 12 月期间处于低水平，并在 1 月和 2 月增加，然后在 3 月中旬达到高峰。甲型 H3N2 病毒总体上占主导地位，但甲型 H1N1pdm09（pH1N1）和乙型流感病毒也广泛传播。与近年来相比，本流感季节较为温和，因流感样疾病（ILI）就诊的门诊百分比较低，†住院率较低，因肺炎和流感导致的死亡人数较少。本报告总结了 2011-12 年流感季节（2011 年 10 月 2 日至 2012 年 5 月 19 日）期间美国的流感活动情况，并报告了 2012-13 年北半球流感疫苗成分的建议。
