Analysis of influenza A viruses from gulls: An evaluation of inter-regional movements and interactions with other avian and mammalian influenza A viruses

Abstract

Birds, including members of the families Anatidae (waterfowl) and Laridae (gulls and terns), serve as the major reservoir of influenza A viruses (IAVs). The ecogeographic contributions of gulls to global IAV dynamics, in terms of geographic scale and virus movements, are important and are distinct from those of waterfowl. Gulls primarily carry the H13 and H16 subtypes, yet can be infected by additional subtypes. Also, gulls are frequently infected by IAVs that contain mixtures of genes from different geographic phylogenetic lineages (e.g. North American and Eurasian). The present analysis examines a variety of viruses isolated from gulls and terns across the world that exhibit particularly high phylogenetic affinities to viruses found in other hosts. This illustrates the potential for gulls to act as highly pathogenic virus carriers, disseminators of viruses over long distances, and contributors in the genesis of pandemic strains. The historical evolution of an entirely Eurasian gull virus isolated in North America was also traced and indicates the Caspian Sea, in southwestern Asia, was an important area for the generation of this virus, and analysis of IAVs from terns also points to this region as relevant for the generation of novel strains.

Keywords:

• IAV
• gene migration
• virus evolution
• inter-species transmission

Public Interest Statement

Influenza A viruses are most well known for their effects on human health and the agriculture industry. However, the movement of these viruses among their natural reservoir species, which are wild birds, plays an important role in these human society-affecting outcomes. Within wild birds, gulls are one important host group and the dynamics of influenza A virus transmission and evolution within this group need to be considered alongside the dynamics in other host groups. This paper presents an analysis of gull viruses and gull biology relevant to this topic.

Competing Interests

The authors declare no competing interest.

Acknowledgments

We thank M. Canuti for comments on the manuscript.

Additional information

Notes on contributors

Andrew S. Lang

Research on influenza A viruses in the laboratory of Andrew Lang is focused on identification and characterization of viruses from wild birds. There is a particular emphasis on the study of gulls and seabirds as hosts of influenza A viruses, and this research is focused in the North Atlantic region of North America. These viruses are analyzed for their evolutionary relationships with those from other species and locations to follow virus transmission among different hosts and regions.