Division of International Epidemiology and Population Studies, Fogarty International Center, National Institutes of Health, 16 Center Drive, Bethesda, MD 20892, USA.
Clin Infect Dis. 2011 Nov;53(10):985-93. doi: 10.1093/cid/cir644. Epub 2011 Oct 5.
The mortality burden of the 2009 A/H1N1 influenza pandemic remains controversial, in part because of delays in reporting of vital statistics that are traditionally used to measure influenza-related excess mortality. Here, we compare excess mortality rates and years of life lost (YLL) for pandemic and seasonal influenza in Mexico and evaluate laboratory-confirmed death reports.
Monthly age- and cause-specific death rates from January 2000 through April 2010 and population-based surveillance of influenza virus activity were used to estimate excess mortality and YLL in Mexico. Age-stratified laboratory-confirmed A/H1N1 death reports were obtained from an active surveillance system covering 40% of the population.
The A/H1N1 pandemic was associated with 11.1 excess all-cause deaths per 100,000 population and 445,000 YLL during the 3 waves of virus activity in Mexico, April-December 2009. The pandemic mortality burden was 0.6-2.6 times that of a typical influenza season and lower than that of the severe 2003-2004 influenza epidemic. Individuals aged 5-19 and 20-59 years were disproportionately affected relative to their experience with seasonal influenza. Laboratory-confirmed deaths captured 1 of 7 pandemic excess deaths overall but only 1 of 41 deaths in persons >60 years of age in 2009. A recrudescence of excess mortality was observed in older persons during winter 2010, in a period when influenza and respiratory syncytial virus cocirculated.
Mexico experienced higher 2009 A/H1N1 pandemic mortality burden than other countries for which estimates are available. Further analyses of detailed vital statistics are required to assess geographical variation in the mortality patterns of this pandemic.
2009 年甲型 H1N1 流感大流行的死亡负担仍然存在争议，部分原因是传统上用于衡量流感相关超额死亡率的生命统计数据报告存在延迟。在这里，我们比较了墨西哥大流行流感和季节性流感的超额死亡率和生命损失年数（YLL），并评估了实验室确诊的死亡报告。
使用 2000 年 1 月至 2010 年 4 月的每月年龄和病因特异性死亡率以及基于人群的流感病毒活动监测数据，估计墨西哥的超额死亡率和 YLL。从覆盖 40%人口的主动监测系统获得了分层年龄的实验室确诊 A/H1N1 死亡报告。
甲型 H1N1 大流行在墨西哥的 3 波病毒活动期间，与每 10 万人中 11.1 例全因超额死亡和 44.5 万例 YLL 相关。大流行的死亡负担是典型流感季节的 0.6-2.6 倍，低于 2003-2004 年严重流感流行的水平。与季节性流感相比，5-19 岁和 20-59 岁的人群受到的影响不成比例。实验室确诊的死亡人数总体上仅占大流行超额死亡人数的 1/7，但在 2009 年，60 岁以上人群的死亡人数中仅占 1/41。在 2010 年冬季，流感和呼吸道合胞病毒同时流行期间，老年人群中观察到超额死亡人数再次增加。
与其他有估计数据的国家相比，墨西哥在 2009 年甲型 H1N1 流感大流行中经历了更高的死亡负担。需要进一步分析详细的生命统计数据，以评估该大流行的死亡率模式的地理差异。
