Public Health-Seattle & King County, 401 Fifth Ave, CNK-0900, Seattle, WA 98104, USA.
Disaster Med Public Health Prep. 2009 Dec;3 Suppl 2:S109-16. doi: 10.1097/DMP.0b013e3181c6b818.
In April 2009, King County, Washington, experienced a sustained outbreak of 2009 H1N1 influenza A. This report describes the epidemiology of that outbreak in King County, home to a diverse population of 1.9 million people.
The 2 primary sources of data are case investigations of reported laboratory-confirmed 2009 H1N1 influenza A and a population-based syndromic surveillance system that captures data from emergency departments (EDs). A syndromic category for influenza-like illness was defined based on chief complaint and diagnosis.
ED visits for influenza-like illness peaked quickly in the first week of the outbreak and remained high for approximately 6 weeks, with school-age children accounting for the greater number of ED visits, followed by young adults. Children ages 0 to 4 years had the highest rate of hospitalization. Among reported cases, blacks, Asians, and Hispanics were more likely to be hospitalized. Predisposing factors associated with admission were immune compromise, chronic lung disease, chronic heart disease, pregnancy, diabetes, and asthma. Of people receiving antiviral treatment, 34% started their medication more than 2 calendar days after the onset of illness. Mean days between illness onset and antiviral treatment were greater for blacks, Hispanics, and foreign language speakers.
The spring 2009 influenza A H1N1 outbreak disproportionately affected children, young adults, and racial and ethnic minorities. Opportunities exist to improve the timeliness of antiviral treatment. Potential barriers to care for racial and ethnic minorities should be proactively addressed to ensure prompt evaluation and treatment.
2009 年 4 月，华盛顿州金县经历了一场持续的 2009 年 H1N1 甲型流感爆发。本报告描述了金县（拥有 190 万人口的多样化社区）爆发疫情的流行病学情况。
数据的 2 个主要来源是对报告的实验室确诊的 2009 年 H1N1 甲型流感病例的调查和基于人群的症状监测系统，该系统从急诊科（ED）捕获数据。根据主要投诉和诊断，定义了流感样疾病的症状类别。
流感样疾病的急诊科就诊量在疫情的第一周迅速达到高峰，并持续高企约 6 周，学龄儿童就诊量较大，其次是年轻成年人。0 至 4 岁的儿童住院率最高。在报告病例中，黑人、亚洲人和西班牙裔更有可能住院。与入院相关的易患因素包括免疫功能低下、慢性肺病、慢性心脏病、妊娠、糖尿病和哮喘。接受抗病毒治疗的人群中，有 34%的人在发病后超过 2 个日历日才开始服用药物。发病后开始抗病毒治疗的平均天数因黑人、西班牙裔和讲外语的人而增加。
2009 年春季甲型 H1N1 流感爆发对儿童、年轻成年人以及种族和族裔少数群体的影响不成比例。有机会提高抗病毒治疗的及时性。应主动解决种族和族裔少数群体的护理障碍，以确保及时评估和治疗。
