Impact of China's COVID-19 prevention and control efforts on outbreaks of influenza

The COVID-19 pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has resulted in a serious public health burden. As the COVID-19 epidemic in China would coincide with a seasonal outbreak of influenza, there were serious concerns about whether influenza would be aggravated by the SARS-CoV-2 infection and COVID-19 pandemic. This article provides a brief overview of the impacts of the COVID-19 epidemic on influenza activity in China. The percentage of positive influenza tests decreased during the COVID-19 pandemic. During the first stage of the COVID-19 outbreak, the percentage of positive influenza tests reached to a peak of 47.7%. At the second stage, the percentage of positive influenza tests was dramatically decreased from 40.4% to 14.0%. Thereafter, it remains at a low level of less than 6.2%. In addition, the possible causes of this phenomenon have been summarized, including prevention and control measures and ecological competition. Lastly, this article suggests that the public health approach to preventing COVID-19 may also help to control other respiratory infectious diseases. Public health measures need to be maintained even in the later stages of the COVID-19 epidemic.