The influence of COVID-19 prevention and control measures on the epidemic of influenza in Huzhou / 预防医学

ABSTRACT

Objective@#To evaluate the impact of coronavirus disease 2019 ( COVID-19 ) prevention and control measures in Huzhou on influenza epidemic strength and characteristics in 2020, so as to provide reference for formulating influenza prevention measures. @*Methods@#Using the influenza surveillance data of the national influenza sentinel surveillance system from January 2015 to July 2020, the seasonal characteristics of influenza epidemic were analyzed, the proportion of influenza-like illness cases ( ILI% ) and the positive rate of influenza virus in January to July of 2020 were compared with those of the same period in 2015-2019, in order to evaluate the impact of COVID-19 prevention and control measures. @*Results @#The ILI% and the positive rate of influenza virus in Huzhou were 3.90% and 15.32% during 2015-2019, while were 4.41% and 12.63% from January to July of 2020. The trends of ILI% during 2015-2019 fluctuated similar, but continued to drop since January 2020. The positive rate of influenza virus peaked from December to March in 2015-2019, also peaked from December 2019 to January 2020, but decreased to 0 in March. ILI% was positively correlated with the positive rate of influenza virus ( r=0.682, P<0.05). The growth rates of ILI% from January to July 2020 were 4.75%, -11.27%, 0.68%, 19.84% and 0.92%, compared with the same period of 2015-2019, respectively. The growth rates of ILI% in January 2020 were much higher ( >57.00% ) and from April to July were much lower ( <-33.00% ) . The growth rates of influenza virus positive rate from January to July 2020 were -47.96%, -36.53%, -3.44%, -35.92% and -39.37%, compared to the same period of 2015-2019, respectively. The growth rates of influenza virus positive rate in January 2020 were much higher ( >11.00% ) and from February to March were much lower ( <-61.00% ). @*Conclusion@#Since COVID-19 prevention and control measures were implemented in January 2020 in Huzhou, the ILI% and the positive rate of influenza virus in sentinel hospitals decreased significantly.