Objective To explore the effectiveness of the cumulative sum (CUSUM) and the exponentially weighted moving average (EWMA) for early warning of influenza epidemic using two datasets of reported influenza cases and influenza-like illness (ILI) cases. Methods Using the reported cases of influenza and ILI in Daxing District, Beijing, from week 23 of 2018 to week 22 of 2024 as data sets, the CUSUM and EWMA models were established, respectively. The positive rate of influenza etiology was used as the ^“gold standard^”, and the Youden index was used as the evaluation index to compare the early warning effect of the two models under different data sets and different parameters. Results In CUSUM, the optimal Youden indices of the reported influenza cases set and the ILI cases set were 0.751 and 0.635, respectively. In EWMA, the optimal Youden indices of the reported influenza cases set and the ILI cases set were 0.544 and 0.464, respectively. The optimal EWMA and CUSUM models could both issue early warning signals in advance of the ^“gold standard^”. Conclusion In the influenza epidemic early warning in Daxing District, Beijing, the CUSUM model established with the reported cases of influenza can achieve good early warning effects, but the model parameters need to be dynamically adjusted according to the local epidemic characteristics.

Objective To analyze the effects of change water sources on population iodine nutrition and goiter status in historical high water-iodine area in Yufa Town of Daxing District,Beijing,and evaluate the control effects.Methods A retrospective analysis method was used to collect epidemiological survey data such as water iodine content,urinary iodine content and goiter rate before and after iodine reduction in Yufa Town of Daxing District,Beijing,2005-2016,and the data were compared and analyzed.Results Yufa Town had implemented water reform since 2005.As of 2015,8 change water source projects had been built,and all historical high-water iodine villages had completed drinking water transformation.Totally 64,12,26,26,and 37 water samples were collected and tested in 2005,2009,2010,2011,and 2014,the medians of water iodine were 185.2,20.9,14.1,16.8,and 21.6 μg/L,respectively,and the medians of water iodine decreased significantly through changing water source.Totally 148,153,150,and 40 urine samples of children aged 8 to 10 years old were collected and tested in 2005,2009,2011,and 2016,the medians of urinary iodine were 520.1,201.6,143.0,and 135.0 μg/L,respectively,and the medians of urinary iodine decreased to a suitable range (100-199 μg/L) through changing water source.Totally 154,292,40,and 40 school-age children were tested for thyroid volume in 2005,2009,2011,and 2016,and 10,6,0,and 1 thyroid enlargements were detected,respectively.The thyroid enlargement rates were 6.49％.2.05％,0,and 2.50％,and the rates of goiter were reduced to less than 5％ through changing water source.Conclusion The high water-iodine in water-borne high iodine area in Yufa Town,Daxing District,Beijing is basically eliminated after change water sources,water improvement to reduce iodine is a basic measure to control high iodine damage in high water-iodine areas.