新型冠状病毒肺炎疫情防控措施对重庆市流行性感冒传播和流行的影响

目的 分析新冠肺炎疫情的防控措施对重庆市流感传播和流行的影响，为制定有针对性的流感防控措施提供重要参考。方法 通过国家流感哨点监测系统收集重庆市2018—2020年流感监测资料，分析流感流行的季节性特征，比较2020年与2018—2019年各年同期流感样病例百分比（ILI%）和流感病毒核酸阳性率，评价新冠肺炎疫情防控对流感流行特征的影响。结果 流感监测资料和实验室检测结果显示，2018—2020年度重庆市报告ILI%依次为3.53%、2.23%和1.20%；流感病毒核酸阳性检出率分别为13.97%、23.81%和2.65%。2018—2019年ILI%分布相似，2020年2月开始，ILI%骤降并维持在较低水平。流感病毒核酸阳性率在2018—2019年每年12月至次年3月达到高峰，2020年2月后迅速下降，3月降为0。ILI%与流感病毒核酸阳性率呈正相关（r=0.404 8,P<0.05）。2020年与2018—2019年各年同期相比，ILI%增长率分别为-66.09%和-46.32%，流感病毒核酸阳性率分别下降81.03%和88.87%，其中1月降幅较小，下降率为39.87%;2...

The influence of COVID-19 prevention and control measures on the transmission and epidemic of influenza in Chongqing

Objective To evaluate the influence of coronavirus disease 2019 (COVID-19) prevention and control measures on the transmission and epidemic of influenza in Chongqing, so as to provide references for formulating targeted influenza prevention and control strategies. Methods The influenza surveillance data, during the year 2018 to 2020, were collected through the "China Influenza Surveillance Information System", and the seasonal characteristics of influenza epidemic were analyzed. The percentage of influenza like cases (ILI%) and influenza virus positive rate between 2020 and 2018-2019 were compared, so as to evaluate the impact of COVID-19 prevention and control measures on influenza epidemic characteristics. Results The annual proportions of ILI cases in Chongqing were respectively 3.53%, 2.23% and 1.2% from 2018 to 2020, while the positive rates of influenza virus were respectively 13.97%, 23.81% and 2.65%. The distribution trend of ILI% from 2018 to 2019 fluctuated were similar, but it continued to drop and remain at a low level since February 2020. The positive rate of influenza virus showed an epidemic peak from December to March in 2018-2019, also peaked from November 2019 to January 2020, but decreased to 0 in March. ILI% was positively correlated with the positive rate of influenza virus (r= 0.404 8, P<0.05). In 2020, compared with the same period of 2018-2019, the growth rate of ILI% was -66.09% and -46.32%, respectively. The positive rate of influenza virus in 2020 decreased by 81.03% and 88.87% compared with the same period of 2018-2019, respectively. The growth rates of influenza virus positive rate in January 2020 were decreased with a small rate of about 39.87%, and with a significantly decline of more than 93.65% from February. No influenza epidemic was found after March. Conclusions Since COVID-19 prevention and control measures were implemented in January 2020 in Chongqing, the ILI% and the positive rate of influenza virus in sentinel hospitals decreased significantly. In the season of high incidence of respiratory infectious diseases, personal protection and other measures can effectively reduce influenza virus infection. © 2023 China Tropical Medicine. All rights reserved.