Zhang Anna J X, To Kelvin K W, Tse Herman, Chan Kwok-Hung, Guo Kun-Yuan, Li Can, Hung Ivan F N, Chan Jasper F W, Chen Honglin, Tam Sidney, Yuen Kwok-Yung
Research Centre of Infection and Immunology, State Key Laboratory for Emerging Infectious Diseases, Department of Microbiology, The University of Hong Kong, Pokfulam Road, Pokfulam, Hong Kong Special Administrative Region, China.
Clin Vaccine Immunol. 2011 Nov;18(11):1918-24. doi: 10.1128/CVI.05357-11. Epub 2011 Sep 7.
Age-specific epidemiological data on asymptomatic, symptomatic, and severe infections are essential for public health policies on combating influenza. In this study, we incorporated data on microbiologically confirmed infections and seroprevalence to comprehensively describe the epidemiology of pandemic H1N1 2009 influenza. Seroprevalence was determined from 1,795 random serum samples collected in our hospital in January 2007 (before the first wave of the pandemic) and March 2010 (after the second wave). Data on microbiologically confirmed infection and severe cases were obtained from the Centre for Health Protection in Hong Kong. Severe cases were most common in the 51- to 60-year-old age group. The microbiologically confirmed incidence rate was highest for children aged ≤10 years and dropped sharply for the adult population (ρ = -1.0; P < 0.01), but the incidence rate for severe disease was highest for the 51- to 60-year-old age group. For the 51- to 60-year-old age group, the seroprevalence was similar to that for the younger age groups, but the proportion of severe cases relative to seroprevalence was significantly higher than that for 11- to 50-year-old age groups. As judged from the percentage of specimens positive for other respiratory viruses compared with that for pandemic H1N1 virus, the impact of symptomatic disease due to pandemic H1N1 virus was higher than that for other respiratory viruses in people aged ≤50 years. In conclusion, the 51- to 60-year-old age group, which had the highest overall incidence and the highest rate of severe disease but is currently not considered by the World Health Organization to be an at-risk group, should be prioritized for influenza vaccination in areas where universal influenza vaccination is not practiced.
关于无症状、有症状和严重感染的特定年龄流行病学数据对于抗击流感的公共卫生政策至关重要。在本研究中，我们纳入了微生物学确诊感染和血清阳性率的数据，以全面描述2009年甲型H1N1流感大流行的流行病学情况。血清阳性率由2007年1月（在大流行第一波之前）和2010年3月（在第二波之后）在我院采集的1795份随机血清样本确定。微生物学确诊感染和重症病例的数据来自香港卫生防护中心。重症病例在51至60岁年龄组中最为常见。≤10岁儿童的微生物学确诊发病率最高，成年人群发病率急剧下降（ρ = -1.0；P < 0.01），但51至60岁年龄组的重症发病率最高。对于51至60岁年龄组，血清阳性率与较年轻年龄组相似，但重症病例相对于血清阳性率的比例显著高于11至50岁年龄组。从其他呼吸道病毒阳性标本百分比与甲型H1N1大流行病毒阳性标本百分比的比较来看，≤50岁人群中甲型H1N1大流行病毒引起的有症状疾病的影响高于其他呼吸道病毒。总之，51至60岁年龄组总体发病率和重症率最高，但目前世界卫生组织未将其视为高危人群，在未实施普遍流感疫苗接种的地区，该年龄组应优先接种流感疫苗。
