Epidemiological characteristics of 420 influenza A (H1N1) cases confirmed in the early stage of the epidemic in mainland China
10.3760/cma.j.issn.0254-6450.2009.11.002
- VernacularTitle:中国大陆2009年早期确诊的420例甲型H1N1流感病例流行病学特征分析
- Author:
Ya-Pin LI
1
;
Quan QIAN
;
Li-Qun FANG
;
Hong YANG
;
Mao-Ti WEI
;
Yan GAO
;
Hua YANG
;
Yong ZHANG
;
Wu-Chun CAO
Author Information
1. 军事医学科学院微生物流行病研究所
- Keywords:
Influenza A(H1N1);
Epidemiological characteristics
- From:
Chinese Journal of Epidemiology
2009;30(11):1102-1105
- CountryChina
- Language:Chinese
-
Abstract:
Objective To describe the epidemical characteristics of A (H1N1) influenza identified in the early stage (from May 11 to June 22, 2009) of the epidemic, in mainland China. Methods Epidemical characteristics of 420 confirmed A (H1N1) influenza cases reported from May 11 to June 22, 2009 were analyzed descriptively, including the distribution of age, sex, source of infection, main symptoms and incubation period. Results A total of 77.8% early cases in mainland China were imported from other countries. Three countries including America, Canada and Australia were attributed to 90% of the imported cases. Most of the cases were from 6 months to 73 years old, with 94% of them under 50 years. Most of the symptoms would include fever (81%), cough (40%) and sore throat (35%). The mean incubation period of second-generation cases was 4.3 (4.2±1.5) days. Conclusion Imported cases dominated the total cases in the early stage of the epidemic had similar gender distribution of those from exporting countries. Fever, cough and sore throat were the three main symptoms manifested in influenza cases. 2.5±1.9(1-11)days was found in imported cases between the day of off-board and the onset of symptoms. The incubation period was 4.3±1.7 (1-8) days among the secondary cases.
