1951—2020年南京市猩红热时间变化特征及趋势分析

目的 分析南京市1951—2020年猩红热发病率时间序列,了解其变化特征及趋势。方法 运用移动平均、滑动T检验和小波时频分析方法,对南京市1951—2020年猩红热年发病率进行分析。结果 猩红热在南京市呈春夏季和冬季2个发病高峰,年发病率整体呈下降趋势,下降率为0.144 8（发病率/5年）。滑动t检验显示4个下降突变点和3个上升突变点。Morlet小波法时频分析呈现3个中心尺度和周期,分别在4、16和25尺度上,高低发病周期分别为4、8和13年;第1主周期在25尺度。周期分析2014年起猩红热发病呈上升势态。2020年初突发公共卫生应急响应一、二级时,发病明显下降,在三级响应时发病回升。结论 依据猩红热发病的周期性和趋势分析,应该加强对猩红热的监测,及时做好疫情处置,以控制其在人群中的传播。

Temporal variation characteristics and trend analysis of scarlet fever in Nanjing, 1951-2020

Objective To analyze the time series of incidence rate of scarlet fever in Nanjing from 1951 to 2020, and to understand its variation characteristics and trends. Methods The moving average, sliding t test and time-frequency method of wavelet transform were used to analyze the incidence rate of scarlet fever in Nanjing over the period of 1951-2020. Results Scarlet fever experience showed two peaks over the year in spring summer season and winter season respectively in Nanjing. The annual incidence rate was decreasing, with a decreasing rate of 0.144 8 （incidence rate /5 years）. The sliding t test showed 4 descending mutation points and 3 rising mutation points. The time-frequency analysis of Morlet wavelet method showed 3 central scales and cycles, which were 4, 16 and 25 scales respectively, and the high and low incidence cycles were 4, 8 and 13 years respectively. The first main cycle was on the scale of 25. From the cycle analysis results, the incidence of scarlet fever had been rising since 2014. At the beginning of 2020, during the first and second levels of public health emergency response, the incidence decreased significantly, and the incidence increased during the third level response. Conclusion According to the analysis of periodicity and trend of scarlet fever, we should strengthen the monitoring of scarlet fever and deal with the epidemic situation in a timely manner, so as to control its transmission within the population.