[Temporal distribution characteristics of hand, foot and mouth disease in Beijing, 2008-2023]

Objective: To analyze the temporal distribution characteristics of hand, foot and mouth disease (HFMD) in Beijing and provide reference evidence in HFMD prevention and control. Methods: The monthly incidence data of HFMD in Beijing from 2008 to 2023 were collected from Notifiable Disease Management Information System of the Chinese Information System of Disease Control and Prevention, and the epidemiological characteristics of HFMD were analyzed by the methods of time series seasonal decomposition graph, concentration degree, and circular distribution.The WPS office software 2019 was used to clean the data, Python software 3.12 was used to analyze and make statistical charts. Results: The monthly incidence fluctuation of HFMD in Beijing from 2008 to 2015 was higher than that from 2016 to 2022. From 2016 to 2022, the fluctuation range of monthly incidence showed a gradually decreasing trend.From 2008 to 2015, the concentration (M) was 0.58, indicating a relatively strong seasonality; the mean angle (α) calculated by the circular distribution method was 174.95°, and the mean angle standard deviation (s) was 60.43°. The annual incidence peak occurred on June 27, and the incidence peak period was from April 27 to August 27. From 2016 to 2019 and 2023, the M was 0.57, indicating a relatively strong seasonality. The α was 228.05°, and s was 61.44°. The annual incidence peak occurred on August 20, and the incidence peak period was from June 18 to October 21. From 2020 to 2022, the M was 0.42, indicating a seasonality, the α was 238.27° and s was 76.35°. The annual incidence peak occurred on July 15, and the incidence peak period was from June 14 to November 14. The α of 2008-2015, 2016-2019 and 2023, and 2020-2022 were tested by the Watson-Williams method and the difference was statistically significant (F=33 443.09, P<0.001). In 2023, the M was 0.77, indicating a strong seasonality. The incidence peak occurred on September 16, and the incidence peak period was from August 5 to October 28. Conclusions: The seasonality of HFMD in Beijing was obvious from 2008 to 2023, and the incidence peak day and peak period overall had rearward shifts. It is necessary to strengthen the comprehensive analysis of the distribution characteristics at different dimensions and the comprehensive prevention and control in key areas, places, and populations during the peak incidence period.