Identify wild bird species responsible for 2022 introductions of HPAI H5 into Central and South America

Identify the migratory wild bird species that carried highly pathogenic avian influenza H5 viruses from North America to Colombia, Peru, Ecuador, and Venezuela during late 2022, coinciding with autumn migrations to South American wintering grounds, in order to clarify which species seeded these independent introductions documented by phylogeographic analyses.

Background

The review documents that, from late 2022, highly pathogenic avian influenza H5 viruses were introduced multiple times from North America into Central and South American countries including Colombia, Peru, Ecuador, and Venezuela. These introductions were supported by phylogeographic analyses and aligned temporally with autumn migrations.

Despite the temporal match with migration, the specific migratory species implicated in transporting the virus into these regions have not been determined. Resolving this would improve understanding of intercontinental transmission routes and support targeted surveillance and risk assessment for future outbreaks.

References

From late 2022, HPAI H5 viruses reached Central and South America via multiple independent viral introductions from North America to Colombia, Peru, Ecuador and Venezuela, as shown by phylogeographic analyses23,86-89 (Fig. 1). These introductions coincided with autumn migrations to South American wintering grounds90, although the specific species involved remain unclear.

— The role of wild birds in the global highly pathogenic avian influenza H5 panzootic  (2504.11910 - Couty et al., 16 Apr 2025) in Dissemination to Central and South America in 2022-2023