Chinese Journal of Geriatrics 2010;29(10):866-869

doi:10.3760/cma.j.issn.0254-9026.2010.10.025

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

Xinyu LI ; Yang LI ; Xin ZHAO ; Quanyi WANG ; Peng YANG ; Ting GAO ; Ying DENG ; Xinghuo PANG

Keywords

Influenza Avirus,H1N1 subtype; Epidemiologic factors

Country

China

Language

Chinese

Abstract

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.