Seasonal influenza poses a significant public health and economic burden, associated with the outcome of infection and resulting complications. The true burden of the disease is difficult to capture due to the wide range of presentation, from asymptomatic cases to non-respiratory complications such as cardiovascular events, and its seasonal variability. An understanding of the magnitude of the true annual incidence of influenza is important to support prevention and control policy development and to evaluate the impact of preventative measures such as vaccination. We use a dynamic disease transmission model, laboratory-confirmed influenza surveillance data, and randomized-controlled trial (RCT) data to quantify the underestimation factor, expansion factor, and symptomatic influenza illnesses in the US and Canada during the 2011-2012 and 2012-2013 influenza seasons. Based on 2 case definitions, we estimate between 0.42−3.2% and 0.33−1.2% of symptomatic influenza illnesses were laboratory-confirmed in Canada during the 2011-2012 and 2012-2013 seasons, respectively. In the US, we estimate between 0.08−0.61% and 0.07−0.33% of symptomatic influenza illnesses were laboratory-confirmed in the 2011-2012 and 2012-2013 seasons, respectively. We estimated the symptomatic influenza illnesses in Canada to be 0.32−2.4 million in 2011-2012 and 1.8−8.2 million in 2012-2013. In the US, we estimate the number of symptomatic influenza illnesses to be 4.4−34 million in 2011-2012 and 23−102 million in 2012-2013. We illustrate that monitoring a representative group within a population may aid in effectively modelling the transmission of infectious diseases such as influenza. In particular, the utilization of RCTs in models may enhance the accuracy of epidemiological parameter estimation.

中文翻译：

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量化季节性流感的年发病率和低估：一种建模方法。

季节性流感给感染和后果造成严重的公共健康和经济负担。由于表现形式多样，从无症状病例到非呼吸系统并发症（如心血管事件）及其季节性变化，很难真正把握疾病的真正负担。了解流感实际年度发病率的大小对于支持预防和控制政策的制定以及评估预防措施（如疫苗接种）的影响非常重要。我们使用动态疾病传播模型，实验室确认的流感监测数据和随机对照试验（RCT）数据来量化低估因子，扩展因子，和2011-2012年和2012-2013年流感季节期间在美国和加拿大的症状性流感疾病。根据2个病例的定义，我们估计在2011-2012年和2012-2013年季节期间，加拿大有0.42-3.2％至0.33-1.2％的症状性流感病是实验室确诊的。在美国，我们估计在2011-2012年和2012-2013季节分别有0.08-0.61％和0.07-0.33％的症状性流感疾病是实验室确诊的。我们估计加拿大的症状性流感疾病在2011-2012年为0.32-240万，在2012-2013年为1.8-820万。在美国，我们估计2011-2012年有症状流感疾病的数量为4.4-3400万，2012-2013年为23-1.02亿。我们说明，监测人群中的代表性人群可能有助于有效地模拟传染病（例如流感）的传播。特别是，在模型中利用随机对照试验可以提高流行病学参数估计的准确性。