Chowell G, Miller M A, Viboud C
Theoretical Division (MS B284), Los Alamos National Laboratory, Los Alamos, NM 87544, USA.
Epidemiol Infect. 2008 Jun;136(6):852-64. doi: 10.1017/S0950268807009144. Epub 2007 Jul 18.
Recurrent epidemics of influenza are observed seasonally around the world with considerable health and economic consequences. A key quantity for the control of infectious diseases is the reproduction number, which measures the transmissibility of a pathogen and determines the magnitude of public health interventions necessary to control epidemics. Here we applied a simple epidemic model to weekly indicators of influenza mortality to estimate the reproduction numbers of seasonal influenza epidemics spanning three decades in the United States, France, and Australia. We found similar distributions of reproduction number estimates in the three countries, with mean value 1.3 and important year-to-year variability (range 0.9-2.1). Estimates derived from two different mortality indicators (pneumonia and influenza excess deaths and influenza-specific deaths) were in close agreement for the United States (correlation=0.61, P60%) in healthy individuals who respond well to vaccine, in addition to periodic re-vaccination due to evolving viral antigens and waning population immunity.
在全球范围内，季节性流感疫情反复出现，造成了相当大的健康和经济后果。控制传染病的一个关键指标是繁殖数（reproduction number），它衡量病原体的传播能力，并决定控制疫情所需的公共卫生干预措施的力度。在此，我们应用一个简单的疫情模型，根据流感死亡率的每周指标，估算美国、法国和澳大利亚三个国家三十年间季节性流感疫情的繁殖数。我们发现这三个国家繁殖数估计值的分布相似，平均值为1.3，且年际变化较大（范围为0.9至2.1）。在美国，由两种不同死亡率指标（肺炎和流感超额死亡数以及流感特异性死亡数）得出的估计值高度一致（相关性=0.61，P<0.001）。此外，由于病毒抗原不断演变以及人群免疫力逐渐减弱，除了定期重新接种疫苗外，健康个体对疫苗反应良好时，超过60%的流感感染可通过疫苗预防。
