Division of Infectious Diseases, Department of Medicine, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, USA.
Infect Control Hosp Epidemiol. 2010 Jul;31(7):676-82. doi: 10.1086/653204.
There are limited data comparing the clinical presentations, comorbidities, and outcomes of patients with infections due to seasonal influenza with patients with infections due to pandemic (H1N1) 2009 influenza.
To compare the epidemiological characteristics and outcomes of pandemic (H1N1) 2009 influenza with those of seasonal influenza.
A cross-sectional study was conducted among patients who received diagnoses during emergency department and inpatient encounters at 2 affiliated academic medical centers in Philadelphia, Pennsylvania. Cases of seasonal influenza during the period November 1, 2005, through June 1, 2008, and cases of pandemic influenza during the period from May 1, 2009, through August 7, 2009, were identified retrospectively.
Forty-nine cases of pandemic influenza and 503 cases of seasonal influenza were identified. Patients with pandemic H1N1 were younger (median age, 29 years) than patients with seasonal influenza (median age, 59 years) (P<.001). More patients with pandemic H1N1 (35 [71%] of 49) were African American, compared with patients with seasonal influenza (267 [53%] of 503; P=.02). Several symptoms were more common among patients with pandemic influenza infections than among patients with seasonal influenza infections: cough (98% vs 83%; P=.007), myalgias (71% vs 46%; P=.001), and pleuritic chest pain (45% vs 15%; P<.001). Pregnancy was the only comorbidity that occurred significantly more often in the pandemic influenza group than in the seasonal influenza group (16% vs 1%; P<.001). There were no significant differences in frequencies of deaths of hospitalized patients, intensive care unit admission, or length of hospitalization between groups.
Other than pregnancy, there were few clinically important differences between infections due to seasonal influenza and those due to pandemic influenza. The greater rate of lower respiratory tract symptoms in pandemic cases might serve to differentiate pandemic influenza from seasonal influenza.
目前有关季节性流感和大流行（H1N1）2009 流感所致感染患者的临床表现、合并症和结局的比较数据有限。
比较大流行（H1N1）2009 流感与季节性流感的流行病学特征和结局。
在宾夕法尼亚州费城的 2 所学术医学中心的急诊和住院患者中进行了一项横断面研究。回顾性确定了 2005 年 11 月 1 日至 2008 年 6 月 1 日期间的季节性流感病例和 2009 年 5 月 1 日至 2009 年 8 月 7 日期间的大流行流感病例。
共发现 49 例大流行 H1N1 流感和 503 例季节性流感。大流行 H1N1 流感患者（中位年龄，29 岁）比季节性流感患者（中位年龄，59 岁）年轻（P<.001）。与季节性流感患者（503 例中的 267 例[53%]）相比，更多的大流行 H1N1 流感患者（49 例中的 35 例[71%]）为非裔美国人（P=.02）。与季节性流感感染患者相比，大流行流感感染患者中出现几种症状的比例更高：咳嗽（98% vs 83%；P=.007）、肌痛（71% vs 46%；P=.001）和胸膜炎性胸痛（45% vs 15%；P<.001）。妊娠是大流行流感组比季节性流感组更常见的唯一合并症（16% vs 1%；P<.001）。两组患者的住院患者死亡率、重症监护病房入院率或住院时间无显著差异。
除妊娠外，季节性流感和大流行流感所致感染之间几乎没有明显的临床差异。大流行病例下呼吸道症状的发生率较高可能有助于将大流行流感与季节性流感区分开来。
