2016-2021年北京市西城区哨点医院流感样病例监测结果分析

Analysis on surveillance results of influenza-like illness in sentinel hospitals of Xicheng District in Beijing from 2016-2021

目的分析2016-2021年北京市西城区哨点医院流感样病例(influenza-like illness,ILI)流行病学特征和流行性感冒(流感)病原学变化规律,为西城区做好流感疫情防控提供参考依据.方法用描述流行病学方法对2016年第18周至2021年第17周北京市西城区哨点医院ILI信息进行流行病学分析,并对ILI监测结果进行病原学分析.结果2016年第18周至2021年第17周北京市西城区哨点医院累计报告ILI 436631例,门急诊病例数14433432例,ILI构成比为3.03%.5个年度ILI报告数均呈现冬春季高峰,其中2016-2017、2017-2018、2018-2019年度高峰时间相近,2019-2020年度高峰结束时间早于往年,2020-2021年度各时期流感样病例报告数均低于往年同期.各年度ILI发病均以<5岁人群为主,其次是5~<15岁人群.5个年度共采集ILI咽拭子标本12882件,流感病毒阳性标本1531件,总阳性率为11.88%.2016-2017、2017-2018、2018-2019年度的流感病毒阳性率较高,2019-2020年度流感病毒阳性率显著低于前3年,2020-2021年度降为0.各年度不同年龄组流感病毒阳性率比较,差异均有统计学意义(均P<0.05).各年度均以甲型流感流行为主,2017-2018、2018-2019、2019-2020年度兼有乙型流感流行.结论2016-2020年北京市西城区ILI报告数和流感病毒阳性率呈现冬春季高峰,ILI报告以<15岁为主要人群,优势毒株交替流行;新型冠状病毒肺炎疫情后,ILI报告数和流感病毒阳性率均明显下降.

Objective To analyze the epidemiological characteristics and change rules of influenza etiology of influenza-like illness(ILI) cases in sentinel hospitals of Xicheng District in Beijing from 2016-2021,provide scientific basis for influenza epidemic prevention and control in Xicheng District. Methods The data of ILI cases in sentinel hospitals of Xicheng District in Beijing from the 18th week of 2016 to the 17th week of 2021 were analyzed by descriptive epidemiology,and the surveillance results of ILI cases were analyzed by etiology. Results From the 18th week of 2016 to the 17th week of 2021,a total of 436 631 ILI cases were reported in sentinel hospitals in Xicheng District of Beijing. There were 14 433 432 cases in the outpatient and emergency departments,and the constituent ratio of ILI was 3.03%. The number of ILI reported cases in the five years showed peak in winter and spring,with similar time distribution in 2016-2017,2017-2018 and 2018-2019,the peak end time in 2019-2020 was earlier than the same period in previous years,and the number of ILI reported cases in 2020-2021 were all lower than the same period in previous years. The ILI cases in each year were mainly in <5 years old people,followed by 5-<15 years old people. A total of12 882 specimens were collected from throat swabs of ILI cases in five years,and 1 531 specimens were positive for influenza virus,with a total positive rate of 11.88%. The positive rate of influenza virus in 2016-2017,2017-2018 and 2018-2019 was higher,while the positive rate in 2019-2020 was significantly lower than that in previous three years,and decreased to 0 in2020-2021. There were statistically significant differences in the positive rate of influenza virus in different age groups in each year(all P <0.05). Influenza A was predominant in all years,and influenza B was prevalent in 2017-2018,2018-2019 and 2019-2020.Conclusion The number of ILI reported cases and the positive rate of influenza virus in Xicheng District of Beijing peak in winter and spring from 2016 to 2020,the ILI cases are mainly reported in <15 years old population,with dominant strains circulating alternately,and the number of ILI reported cases and the positive rate of influenza virus decreased significantly after the epidemic of Coronavirus Disease 2019.