School of Public Health, Southern Medical University, Guangzhou, China; Guangdong Provincial Center for Disease Control and Prevention, Guangzhou, China.
Guangdong Provincial Center for Disease Control and Prevention, Guangzhou, China.
Int J Infect Dis. 2021 Mar;104:594-600. doi: 10.1016/j.ijid.2021.01.058. Epub 2021 Jan 27.
The moving epidemic method (MEM) has been well used for assessing seasonal influenza epidemics in temperate regions. This study used the MEM to establish epidemic threshold for influenza in Guangdong, a subtropical province in China.
Influenza virology surveillance data from 2011/2012 to 2017/2018 seasons in Guangdong were used with the MEM to calculate the epidemic thresholds and timeously detect the 2018/2019 influenza season epidemic. The weekly positive proportion of influenza A(H1N1)pdm09, A(H3N2), B/Victoria-lineage and B/Yamagata-lineage were separately adapted to calculate the subtype-specific epidemic thresholds. The performance of MEM was evaluated using a cross-validation procedure.
For the 2018/2019 influenza season, the epidemic threshold of a weekly positive proportion was 15.08%. Epidemic detection for the 2018/2019 season was 1 week in advance. Influenza A(H1N1)pdm09, B/Yamagata-lineage and B/Victoria-lineage prevailed during winter and spring and their epidemic thresholds were 5.12%, 4.53% and 4.38%, respectively. Influenza A(H3N2) was active in the summer, with an epidemic threshold of 11.99%.
Using influenza virology surveillance data stratified by types of influenza virus, the MEM was effectively used in Guangdong, China. This study provided a practical way for subtropical regions to establish local influenza epidemic thresholds.
移动疫情法（MEM）已被广泛用于评估温带地区的季节性流感疫情。本研究使用 MEM 建立了中国亚热带省份广东的流感流行阈值。
利用广东 2011/2012 至 2017/2018 流感季节的流感病毒学监测数据，采用 MEM 计算流行阈值并及时检测 2018/2019 流感季节的疫情。分别适应流感 A（H1N1）pdm09、A（H3N2）、B/Victoria 谱系和 B/Yamagata 谱系的每周阳性比例来计算亚型特异性流行阈值。通过交叉验证程序评估 MEM 的性能。
对于 2018/2019 流感季节，每周阳性比例的流行阈值为 15.08%。对 2018/2019 季节的流行检测提前了 1 周。流感 A（H1N1）pdm09、B/Yamagata 谱系和 B/Victoria 谱系在冬春季流行，其流行阈值分别为 5.12%、4.53%和 4.38%。流感 A（H3N2）在夏季活跃，流行阈值为 11.99%。
使用按流感病毒类型分层的流感病毒学监测数据，MEM 在广东得到了有效应用。本研究为亚热带地区建立本地流感流行阈值提供了一种实用方法。
