Abstract:

The COVID-19 pandemic has influenced human behaviours, which have in turn influenced respiratory disease transmission (e.g. influenza). In Hong Kong, during the COVID-19 pandemic, the number of closely contacted people reduced by 59% and the total close contact time reduced by 10%. These changes in human behaviours reduced the effective reproduction number of influenza from 1.41 at the end of December 2019 to 0.52 on 19 February 2020, a reduction of 63.1%. Close contact control contributed more than 47% to infection risk reduction, confirming that human behaviours were significantly influenced by the COVID-19 pandemic. These human behaviour changes in turn reduced the spread of other respiratory infections such as influenza. Thus, promoting positive human behaviours should be an important factor in intervention policies against infectious diseases.