Background: This study aimed to investigate region-specific epidemiologic characteristics of influenza and influenza transmission zones (ITZs).

Methods: Weekly influenza surveillance data of 156 countries from 1996 to 2021 were obtained using FluNet. Join-point regression was used to describe global influenza virus trends, and clustering analyses were used to classify the ITZs.

Results: The global median average positive rate for total influenza virus was 16.19% (interquartile range [IQR]:11.62%-25.70%). Overall, three major subtypes (influenza H1, H3, and B viruses) showed alternating epidemics. Notably, the proportion of influenza B viruses increased significantly from July 2020 to June 2021, reaching 62.66%. The primary peaks of influenza virus circulation in the north were earlier than those in the south. Global influenza virus circulation was significantly characterised by seven ITZs, including "Northern-America" (primary peak: week 10), "Eastern & Southern-Asia" (primary peak: week 10), "Europe" (primary peak: week 11), "Asia-Europe" (primary peak: week 12), "Southern-America" (primary peak: week 30), "Oceania-Melanesia-Polynesia" (primary peak: week 39), and "Africa" (primary peak: week 46).

Conclusions: Global influenza virus circulation was significantly characterised by seven ITZs that could be applied to influenza surveillance and warning.