2009年北京市老年人甲型H1N1流感流行病学分析

Epidemiological analysis of elderly cases with the 2009 influenza A （H1N1） in Beijing

目的 分析2009年北京市老年人感染甲型H1N1流感（甲流）分布特征.方法 采用描述性流行病学研究方法对2009年北京市老年人甲流进行流行特征分析.结果北京市老年人确诊甲流病例321例,确诊发病率为13.2/10万;11、12月份发病最多,占84.7%;地区分布中以近郊区分布最多,占53.0%;通过年龄分布分析发现,85岁以上年龄组发病率最高,为19.2/10万,并随着年龄增长病情有加重趋势（x2=7.24,P＜0.01）;病例分型中轻症比例最高,占63.6%,重症和危重症病例占36.4%;轻、重、危重病例之间的体质指数（BMI）差异无统计学意义（x2=8.14,P=0.52）;甲流病情有随着基础性疾病加重的趋势,病情程度与基础性疾病的数量有关（x2=123.0,P＜0.01）.结论 北京市老年人甲流发病率较高,危重症比例较大,应是重点防控的人群之一.

Objective To analyze epidemiological characteristics of elderly cases with influenza A （H1N1） in Beijing. Methods Descriptive epidemiological methods were used to describe epidemiological characteristics of elderly cases with 2009 influenza A （H1N1） in Beijing. Results The 321 laboratory-confirmed elderly cases with influenza A （H1N1） were reported in Beijing, and the morbidity was 13.2/100 000. The peak of infection occurred during November and December, the cases in this period accounted for 84.7% of the whole year, and 53.0% of them were reported in suburb areas, with the highest morbidity （19.2/100 000） in people beyond 85 years, and the morbidity increased with age （x2 = 7.24, P＜0.01）. The mild cases accounted for 63.6 %, severe and critical cases accounted for 36.4%. No significant difference was found between severity and BMI （x2=8.14, P=0.52）. Severity was associated with number of chronic diseases （x2= 123.0, P＜0. 01）. Conclusions The H1N1 morbidity and proportion of severe cases are high among the elderly in Beijing, more attention should be paid to this population for influenza A （H1N1） prevention and control.