Successful interruption of seasonal influenza transmission under the COVID-19 rapid response in Zhejiang Province, China

Objectives

The objective of this study was to evaluate whether the non-pharmaceutical interventions (NPIs) introduced to curb the spread of coronavirus disease 2019 (COVID-19) also interrupted the transmission of influenza.

Study design

This is a descriptive epidemiological study.

Methods

Data on changes in the number of reported influenza cases, number of influenza-like illness (ILI) visits, ILI percentage and influenza virus positivity were compared between the first 18 weeks of 2020 and the same period of 2019.

Results

The changes in the weekly average number of influenza cases were statistically significant between 2020 and 2019 (−4319 vs −525 per week; P < 0.05). The slopes of regression lines for the number of ILI visits were also statistically significant between 2020 and 2019 (−911 vs −98 per week; P < 0.05).

Conclusions

This study found that the prevalence of influenza was substantially decreased when NPIs were implemented for the containment of COVID-19.

•

The prevalence of influenza was substantially decreased when non-pharmaceutical interventions were implemented for the containment of coronavirus disease 2019.

•

Changes in the weekly average number of influenza cases were statistically significant between 2020 and 2019 (−4319 vs −525 per week; P < 0.05).

•

Changes in the number of influenza-like illness visits were also statistically significant between 2020 and 2019 (−911 vs −98 per week; P < 0.05).