Zhou Wangzhan, He Wei, Hu Yunshuang, Zhao Feng, Huang Jianfang
Objective To understand the epidemic situation of influenza A and influenza B in Wenzhou from 2017 to 2019. Methods The throat swabs and clinical data of influenzalike cases from January 2017 to December 2019 in two hospitals in Wenzhou were collected to analyze the number of influenza-like cases and the detection rate of influenza-like cases by gender, age, month and year. Results The number of influenza like cases received from 2017 to 2019 was 32 097, including 2 355 cases (7.3%) in 2017, 8 177 cases (25.5%) in 2018 and 21 565 cases (67.2%) in 2019. The detection rates in 2017, 2018 and 2019 were 44.4%, 35.8% and 39.7% respectively. The detection rates of influenza A were 6.6%, 15.5% and 27.2%, respectively, showing an increasing trend year by year. The detection rate of influenza B was 37.8%, 20.3% and 12.4%, respectively, which decreased year by year. There were 16 750 males (52.1%) and 15 347 females (47.9%) in 32 097 cases of influenza like diseases. From 2017 to 2019, the total detection rate of men was higher than that of women (P<0.001), and the detection rate of influenza A in men was higher than that in women (P<0.001). There was no significant difference between male and female (P=0.408). The age group of 4 to <7 years old and group of 7 to <19 years old were the main groups of influenza epidemic. The highest detection rate was found in the 7 to <19 age group, and the detection rates from 2017 to 2019 were 53.1%, 43.7% and 49.4% respectively. From 2017 to 2019, influenza epidemics were mainly distributed in January, February, March and December, and influenza A and B alternated. Conclusion From 2017 to 2019, influenza A and influenza B alternated in Wenzhou, and winter and spring were the peak periods of influenza; men are more likely to be infected with influenza A than women; The age group of 7 to <19 years old is the main group of influenza, which suggests that the prevention and control of influenza in campus should be done well.