2019—2020年乌鲁木齐市水痘流行强度及高峰期预测研究

Study on varicella epidemic intensity and peak period prediction in Urumqi City from 2019 to 2020

目的 利用移动流行区间法(moving epidemic method, MEM)评估乌鲁木齐市水痘流行强度,建立该市水痘监测阈值,为分级防控提供科学依据。方法 利用MEM对乌鲁木齐市2010—2019年每年第30周至次年第10周水痘监测发病数据建模,筛选指标包括灵敏度、特异度、阳性预测值、阴性预测值、马修斯相关系数和约登指数,评价2019—2020年乌鲁木齐市水痘流行状况。结果 2012—2013年和2018—2019年数据质量较差,予以剔除。利用剩余年份数据重新建模后,最优参数值为3.0,灵敏度、特异度和约登指数分别为0.73、0.98和0.71,模型拟合效果较好。中等、高和极高强度阈值分别为100、126和140例,2019年第36周进入水痘流行前阈值,随后快速上升超过中等强度阈值,并在2019年第45周到达高强度峰值水平。结论 利用MEM建立水痘流行预警模型,可计算水痘的流行开始时间及流行强度,预测疾病流行至高峰期的时间,在水痘的预警中效果较好。

Objective To assess the intensity of varicella epidemics in Urumqi City using the moving epidemic method(MEM),to establish the threshold for varicella surveillance in the city,and to provide a scientific basis for graded prevention and control.Methods MEM was used to model the incidence data of varicella surveillance in Urumqi City from the 30th week of each year to the 10th week of the following year from 2010 to 2019.The screening indexes,including sensitivity,specificity,positive predictive value,negative predictive value,Matthews correlation coefficient,and Youden index,were used to evaluate the epidemic situation of varicella in Urumqi City from 2019 to 2020.Results The data quality from 2012 to 2013 and 2018 to 2019 was poor and was excluded.After remodeling using the data of the remaining years,the optimal parameter value was 3.0,and the sensitivity,specificity and Youden index were 0.73,0.98,and 0.71,respectively,with a good model fitting.The thresholds of moderate,high,and extremely high intensity were 100,126,and 140 cases,respectively.The threshold for pre-epidemic varicella was entered in the 36th week of 2019,followed by a rapid rise above the moderate intensity threshold and reaching the highintensity peak level in the 45th week of 2019.Conclusion The varicella epidemic early warning model established by MEM can calculate the epidemic start time and epidemic intensity of varicella,and predict the time from the epidemic to the peak period,which is more effective in the early warning of varicella.