Abstract：
In Japan, based on the National Epidemiological Surveillance of Infectious Diseases (NESID) Program, influenza cases from ~5,000 sentinel sites are monitored weekly as part of influenza surveillance (as number of influenza cases/sentinel site). One limitation is that the number of influenza tests conducted is not reported. Separately, the National Hospital Organization (NHO), with ~140 hospitals, routinely publishes three indicators: number of influenza tests, influenza-positive case counts, and test positivity. We used NESID and NHO data from April 2011 to June 2022 to assess the usefulness of multiple indicators to monitor influenza activity. Temporal trends of the NHO and NESID indicators were similar, and NHO indicator levels well-correlated with those of the NESID indicator. Influenza positivity in the NHO data, however, showed an earlier rise and peak time compared to the NESID indicator. Importantly, through the non-epidemic summer periods and the coronavirus disease 2019 pandemic, a sizable number of influenza tests continued to be done at NHO hospitals, with results showing considerably low case counts and test positivity. These data show that a relatively small number of sentinel sites is sufficient to monitor influenza activity nationally, and, that utilizing multiple indicators can increase our confidence in situational awareness and data interpretations.
摘要：
在日本,根据国家传染病流行病学监测（NESID）计划，作为流感监测的一部分，每周监测约5,000个哨点的流感病例(作为流感病例/哨点的数量)。一个限制是没有报告进行的流感测试的数量。分别,国家医院组织（NHO），拥有约140家医院，例行发布三个指标：流感测试的数量，流感阳性病例数,和测试积极性。我们使用2011年4月至2022年6月的NESID和NHO数据来评估多种指标监测流感活动的有用性。NHO和NESID指标的时间趋势相似，NHO指标水平与NESID指标水平密切相关。NHO数据中的流感阳性，然而,与NESID指标相比，显示出较早的上升和峰值时间。重要的是,通过非流行的夏季和2019年冠状病毒病的大流行，NHO医院继续进行大量的流感测试，结果显示病例数和测试阳性相当低。这些数据表明，相对较少的哨点足以监测全国的流感活动，and,利用多个指标可以增加我们对态势感知和数据解释的信心。
